1
|
Wong MK, Chen WJ. Exploring the phylogeny and depth evolution of cusk eels and their relatives (Ophidiiformes: Ophidioidei). Mol Phylogenet Evol 2024; 199:108164. [PMID: 39084413 DOI: 10.1016/j.ympev.2024.108164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 07/27/2024] [Accepted: 07/27/2024] [Indexed: 08/02/2024]
Abstract
With 289 known species in 51 genera, the ophidiiform family Ophidiidae together with their relatives from the Carapidae (36 species in eight genera) of the same suborder Ophidioidei dominate the deep sea, but some occur also in shallow water habitats. Despite their high species diversity in the deep sea and wide bathymetric distributions, their phylogenetic relationships and evolution remain unexplored due in part to sampling difficulties. Thanks to the biodiversity exploratory program entitled "Tropical Deep-Sea Benthos" and joint efforts between Taiwan and French teams for sampling from different localities across the Indo-West Pacific over the last two decades, we are able to compile comprehensive datasets for investigations. In this study, 59 samples representing 36 of 59 known ophidioid genera are selected and used to construct a multi-gene dataset to infer the phylogenetic relationships of ophidioid fishes and their relatives. Our results reveal that the Ophidiidae forms a paraphyletic group with respect to the Carapidae. The four main clades of Ophidioidei resolved are the (1) clade comprising species from the subfamily Brotulinae; (2) clade that includes species in the genera Acanthonus and Xyelacyba; (3) clade grouping Hypopleuron caninum with species from the family Carapidae; and (4) clade containing the species in the subfamily Brotulotaenilinae, Neobythitinae (in part), and Ophidiinae. Accordingly, we suggest the following new revisions based on our results and proposed morphological diagnoses. The subfamily Brotulinae should be elevated to the family level. The genera Xyelacyba and probably Tauredophidium (unsampled in this study) should be included in the newly established family Acanthonidae with Acanthonus. The families Carapidae and Ophidiidae are re-defined. Our time-calibrated phylogenetic and ancestral depth reconstructions enable us to clarify the evolutionary history of ophidiiform fishes and infer past patterns of species distributions at different depths. While Ophidiiformes is inferred to have originated in shallow waters around 96.25 million years ago (Mya), the common ancestor to the Ophidioidei is inferred to have invaded the deep sea around 90.22 Mya, the dates coinciding with the global anoxic event of the OAE2. The observed bathymetric distribution patterns in Ophidioidei most likely point to the mesopelagic zone as the center of origin and diversification. This was followed by multiple events of depth transitions or range expansions towards either shallower waters or greater depth zones, which were likely triggered by past climate changes during the Paleogene-Neogene.
Collapse
Affiliation(s)
- Man-Kwan Wong
- Institute of Oceanography, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
| | - Wei-Jen Chen
- Institute of Oceanography, National Taiwan University, No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
| |
Collapse
|
2
|
Brownstein CD, Near TJ. Colonization of the ocean floor by jawless vertebrates across three mass extinctions. BMC Ecol Evol 2024; 24:79. [PMID: 38867201 PMCID: PMC11170801 DOI: 10.1186/s12862-024-02253-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/07/2024] [Indexed: 06/14/2024] Open
Abstract
BACKGROUND The deep (> 200 m) ocean floor is often considered to be a refugium of biodiversity; many benthic marine animals appear to share ancient common ancestry with nearshore and terrestrial relatives. Whether this pattern holds for vertebrates is obscured by a poor understanding of the evolutionary history of the oldest marine vertebrate clades. Hagfishes are jawless vertebrates that are either the living sister to all vertebrates or form a clade with lampreys, the only other surviving jawless fishes. RESULTS We use the hagfish fossil record and molecular data for all recognized genera to construct a novel hypothesis for hagfish relationships and diversification. We find that crown hagfishes persisted through three mass extinctions after appearing in the Permian ~ 275 Ma, making them one of the oldest living vertebrate lineages. In contrast to most other deep marine vertebrates, we consistently infer a deep origin of continental slope occupation by hagfishes that dates to the Paleozoic. Yet, we show that hagfishes have experienced marked body size diversification over the last hundred million years, contrasting with a view of this clade as morphologically stagnant. CONCLUSION Our results establish hagfishes as ancient members of demersal continental slope faunas and suggest a prolonged accumulation of deep sea jawless vertebrate biodiversity.
Collapse
Affiliation(s)
- Chase Doran Brownstein
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA.
| | - Thomas J Near
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA
- Yale Peabody Museum, Yale University, New Haven, CT, 06511, USA
| |
Collapse
|
3
|
Priede IG, Jamieson AJ, Bond T, Kitazato H. In situ observation of a macrourid fish at 7259 m in the Japan Trench: swimbladder buoyancy at extreme depth. J Exp Biol 2024; 227:jeb246522. [PMID: 38230425 PMCID: PMC10917060 DOI: 10.1242/jeb.246522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 01/02/2024] [Indexed: 01/18/2024]
Abstract
A macrourid, Coryphaenoides yaquinae sp. inc., was observed to be attracted to bait and exhibiting normal foraging behaviour during a period of 80 min within view of a baited video camera on the sea floor at 7259 m - the deepest ever observation of a fish species with a swim bladder. The buoyancy provided by an oxygen-filled swim bladder at 74.4 MPa pressure was estimated to be 0.164 N, at a theoretical energy cost of 20 kJ, 200 times less than the cost of equivalent lipid buoyancy. During normal metabolism, 192 days would be required to fill the swimbladder. At these depths, oxygen is very incompressible, so changes in volume during ascent or descent are small. However, swimbladder function is crucially dependent on a very low rate of diffusion of oxygen across the swimbladder wall. The oxygen in the swimbladder could theoretically sustain aerobic metabolism for over 1 year but is unlikely to be used as a reserve.
Collapse
Affiliation(s)
- Imants G. Priede
- School of Biological Sciences, University of Aberdeen, Tillydrone Avenue, Aberdeen AB24 2TZ, UK
| | - Alan J. Jamieson
- Minderoo-UWA Deep-Sea Research Centre, School of Biological Sciences and Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Todd Bond
- Minderoo-UWA Deep-Sea Research Centre, School of Biological Sciences and Oceans Institute, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia
| | - Hiroshi Kitazato
- Department of Marine Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
- Danish Center for Hadal Research, Satellite office at TUMSAT, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| |
Collapse
|
4
|
Haddock SHD, Choy CA. Life in the Midwater: The Ecology of Deep Pelagic Animals. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:383-416. [PMID: 38231738 DOI: 10.1146/annurev-marine-031623-095435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
The water column of the deep ocean is dark, cold, low in food, and under crushing pressures, yet it is full of diverse life. Due to its enormous volume, this mesopelagic zone is home to some of the most abundant animals on the planet. Rather than struggling to survive, they thrive-owing to a broad set of adaptations for feeding, behavior, and physiology. Our understanding of these adaptations is constrained by the tools available for exploring the deep sea, but this tool kit is expanding along with technological advances. Each time we apply a new method to the depths, we gain surprising insights about genetics, ecology, behavior, physiology, diversity, and the dynamics of change. These discoveries show structure within the seemingly uniform habitat, limits to the seemingly inexhaustible resources, and vulnerability in the seemingly impervious environment. To understand midwater ecology, we need to reimagine the rules that govern terrestrial ecosystems. By spending more time at depth-with whatever tools are available-we can fill the knowledge gaps and better link ecology to the environment throughout the water column.
Collapse
Affiliation(s)
- Steven H D Haddock
- Monterey Bay Aquarium Research Institute, Moss Landing, California, USA;
| | - C Anela Choy
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, USA;
| |
Collapse
|
5
|
Baucon A, Ferretti A, Fioroni C, Pandolfi L, Serpagli E, Piccinini A, de Carvalho CN, Cachão M, Linley T, Muñiz F, Belaústegui Z, Jamieson A, Lo Russo G, Guerrini F, Ferrando S, Priede I. The earliest evidence of deep-sea vertebrates. Proc Natl Acad Sci U S A 2023; 120:e2306164120. [PMID: 37669391 PMCID: PMC10500276 DOI: 10.1073/pnas.2306164120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 07/25/2023] [Indexed: 09/07/2023] Open
Abstract
Vertebrate macroevolution has been punctuated by fundamental habitat transitions from shallow marine origins to terrestrial, freshwater, and aerial environments. Invasion of the deep sea is a less well-known ecological shift because of low fossilization potential and continual loss of abyssal fossil record by ocean floor subduction. Therefore, there has been a lack of convincing evidence of bottom-living vertebrates from pre-Paleogene deep seas. Here, we describe trace fossils from abyssal plain turbidites of the Tethys Ocean, which, combined with nannofossil dating, indicate that fishes have occupied the deep seafloor since at least the Early Cretaceous (Hauterivian-Barremian). These structures are identical to those produced by modern demersal fishes that feed by either scratching the substrate or expose their prey by water flow generated by suction or jetting. The trace fossils suggest activity of at least three fish species exploiting a productive abyssal invertebrate sediment fauna. These observations are consistent with Early Cretaceous vertebrate transition to the deep sea triggered by the availability of new food sources. Our results anticipate the appearance of deep-seafloor fishes in the fossil record by over 80 My while reassessing the mode of vertebrate colonization of the deep sea.
Collapse
Affiliation(s)
- Andrea Baucon
- Dipartimento di Scienze della Terra dell'Ambiente e della Vita, Università degli Studi di Genova, Genova 16132, Italy
- Geology Office of Idanha-a-Nova, Naturtejo UNESCO Global Geopark, Castelo Branco 6000, Portugal
- Museum of Nature South Tyrol, Bolzano 39100, Italy
- Dipartimento di Geoscienze, Università di Padova, Padova 35137, Italy
| | - Annalisa Ferretti
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Modena 41125, Italy
| | - Chiara Fioroni
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Modena 41125, Italy
| | - Luca Pandolfi
- Dipartimento di Scienze della Terra, Università di Pisa, Pisa 56126, Italy
| | - Enrico Serpagli
- Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Modena e Reggio Emilia, Modena 41125, Italy
| | - Armando Piccinini
- Spin Off Accademico Gen Tech, Università di Parma, Parma 43121, Italy
| | - Carlos Neto de Carvalho
- Geology Office of Idanha-a-Nova, Naturtejo UNESCO Global Geopark, Castelo Branco 6000, Portugal
- Instituto D. Luiz, Faculdade de Ciências da Universidade de Lisboa, Lisbon 1749-016, Portugal
| | - Mário Cachão
- Instituto D. Luiz, Faculdade de Ciências da Universidade de Lisboa, Lisbon 1749-016, Portugal
| | - Thomas Linley
- School of Natural and Environmental Sciences, Newcastle University, Newcastle Upon Tyne NE1 7RU, United Kingdom
- Armatus Oceanic, Tyne Subsea, National Centre for Subsea and Offshore Engineering, Newcastle Upon Tyne NE28 6DA, United Kingdom
| | - Fernando Muñiz
- Departamento de Cristalografía, Mineralogía y Química Agrícola, Universidad de Sevilla, Sevilla 41012, Spain
| | - Zain Belaústegui
- Departament de Dinàmica de la Terra i de l'Oceà, Facultat de Ciències de la Terra, Universitat de Barcelona, Barcelona 08007, Spain
- Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Barcelona 08007, Spain
| | - Alan Jamieson
- Armatus Oceanic, Tyne Subsea, National Centre for Subsea and Offshore Engineering, Newcastle Upon Tyne NE28 6DA, United Kingdom
- Minderoo-UWA Deep-Sea Research Centre, School of Biological Sciences and Oceans Institute, The University of Western Australia, Perth, WA 6009, Australia
| | | | | | - Sara Ferrando
- Dipartimento di Scienze della Terra dell'Ambiente e della Vita, Università degli Studi di Genova, Genova 16132, Italy
| | - Imants Priede
- Oceanlab, Institute of Biological & Environmental Sciences, University of Aberdeen, Newburgh, Aberdeen AB24 3FX, United Kingdom
| |
Collapse
|
6
|
Rabosky DL. Evolutionary time and species diversity in aquatic ecosystems worldwide. Biol Rev Camb Philos Soc 2022; 97:2090-2105. [PMID: 35899476 PMCID: PMC9796449 DOI: 10.1111/brv.12884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 01/01/2023]
Abstract
The latitudinal diversity gradient (LDG) is frequently described as the most dramatic biodiversity pattern on Earth, yet ecologists and biogeographers have failed to reach consensus on its primary cause. A key problem in explaining the LDG involves collinearity between multiple factors that are predicted to affect species richness in the same direction. In terrestrial systems, energy input, geographic area, and evolutionary time for species accumulation tend to covary positively with species richness at the largest spatial scales, such that their individual contributions to the LDG are confounded in global analyses. I review three diversity patterns from marine and freshwater systems that break this collinearity and which may thus provide stronger tests of the influence of time on global richness gradients. Specifically, I contrast biodiversity patterns along oceanic depth gradients, in geologically young versus ancient lakes, and in the north versus south polar marine biomes. I focus primarily on fishes due to greater data availability but synthesize patterns for invertebrates where possible. I find that regional-to-global species richness generally declines with depth in the oceans, despite the great age and stability of the deep-sea biome. Geologically ancient lakes generally do not contain more species than young lakes, and the Antarctic marine biome is not appreciably more species rich than the much younger Arctic marine biome. However, endemism is consistently higher in older systems. Patterns for invertebrate groups are less clear than for fishes and reflect a critical need for primary biodiversity data. In summary, the available data suggest that species richness is either decoupled from or only weakly related to the amount of time for diversification. These results suggest that energy, productivity, or geographic area are the primary drivers of large-scale diversity gradients. To the extent that marine and terrestrial diversity gradients result from similar processes, these examples provide evidence against a primary role for evolutionary time as the cause of the LDG.
Collapse
Affiliation(s)
- Daniel L. Rabosky
- Museum of Zoology & Department of Ecology and Evolutionary BiologyUniversity of Michigan2032 Biological Sciences BuildingAnn ArborMI48109USA
| |
Collapse
|
7
|
Alternating regimes of shallow and deep-sea diversification explain a species-richness paradox in marine fishes. Proc Natl Acad Sci U S A 2022; 119:e2123544119. [PMID: 36252009 PMCID: PMC9618140 DOI: 10.1073/pnas.2123544119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The deep sea contains a surprising diversity of life, including iconic fish groups such as anglerfishes and lanternfishes. Still, >65% of marine teleost fish species are restricted to the photic zone <200 m, which comprises less than 10% of the ocean's total volume. From a macroevolutionary perspective, this paradox may be explained by three hypotheses: 1) shallow water lineages have had more time to diversify than deep-sea lineages, 2) shallow water lineages have faster rates of speciation than deep-sea lineages, or 3) shallow-to-deep sea transition rates limit deep-sea richness. Here we use phylogenetic comparative methods to test among these three non-mutually exclusive hypotheses. While we found support for all hypotheses, the disparity in species richness is better described as the uneven outcome of alternating phases that favored shallow or deep diversification over the past 200 million y. Shallow marine teleosts became incredibly diverse 100 million y ago during a period of warm temperatures and high sea level, suggesting the importance of reefs and epicontinental settings. Conversely, deep-sea colonization and speciation was favored during brief episodes when cooling temperatures increased the efficiency of the ocean's carbon pump. Finally, time-variable ecological filters limited shallow-to-deep colonization for much of teleost history, which helped maintain higher shallow richness. A pelagic lifestyle and large jaws were associated with early deep-sea colonists, while a demersal lifestyle and a tapered body plan were typical of later colonists. Therefore, we also suggest that some hallmark characteristics of deep-sea fishes evolved prior to colonizing the deep sea.
Collapse
|
8
|
Bo J, Xu H, Lv W, Wang C, He S, Yang L. Molecular Mechanisms of the Convergent Adaptation of Bathypelagic and Abyssopelagic Fishes. Genome Biol Evol 2022; 14:evac109. [PMID: 35866587 PMCID: PMC9348623 DOI: 10.1093/gbe/evac109] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2022] [Indexed: 11/24/2022] Open
Abstract
Harsh environments provide opportunities to study how different species adapt, at the molecular level, to similar environmental stressors. High hydrostatic pressure, low temperature, and absence of sunlight in the deep-sea environment are challenging conditions for gene expression, cell morphology and vision. Adaptation of fish to this environment appears independently in at least 22 orders of fish, but it remains uncertain whether these adaptations represent convergent evolution. In this study, we performed comparative genomic analysis of 80 fish species to determine genetic evidences for adaptations to the deep-sea environment. The 80 fishes were divided into six groups according to their order. Positive selection and convergent evolutionary analysis were performed and functional enrichment analysis of candidate genes was performed. Positively selected genes (pik3ca, pik3cg, vcl and sphk2) were identified to be associated with the cytoskeletal response to mechanical forces and gene expression. Consistent signs of molecular convergence genes (grk1, ednrb, and nox1) in dark vision, skin color, and bone rarefaction were revealed. Functional assays of Grk1 showed that the convergent sites improved dark vision in deep-sea fish. By identifying candidate genes and functional profiles potentially involved in cold, dark, and high-pressure responses, the results of this study further enrich the understanding of fish adaptations to deep-sea environments.
Collapse
Affiliation(s)
- Jing Bo
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Han Xu
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenqi Lv
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cheng Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shunping He
- Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences, Sanya 572000, China
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650223, China
| | - Liandong Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- Academy of Plateau Science and Sustainability, Qinghai Normal University, Xining, China
| |
Collapse
|
9
|
Rodríguez-Flores P, Macpherson E, Schnabel K, Ahyong S, Corbari L, Machordom A. Depth as a driver of evolution and diversification of ancient squat lobsters (Decapoda, Galatheoidea, Phylladiorhynchus). Mol Phylogenet Evol 2022; 171:107467. [DOI: 10.1016/j.ympev.2022.107467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 03/09/2022] [Accepted: 03/15/2022] [Indexed: 11/28/2022]
|
10
|
Maduna SN, Vivian-Smith A, Jónsdóttir ÓDB, Imsland AK, Klütsch CF, Nyman T, Eiken HG, Hagen SB. Mitogenomics of the suborder Cottoidei (Teleostei: Perciformes): Improved assemblies, mitogenome features, phylogeny, and ecological implications. Genomics 2022; 114:110297. [DOI: 10.1016/j.ygeno.2022.110297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 01/05/2022] [Accepted: 02/01/2022] [Indexed: 11/04/2022]
|
11
|
Evolution and phylogeny of the deep-sea isopod families Desmosomatidae Sars, 1897 and Nannoniscidae Hansen, 1916 (Isopoda: Asellota). ORG DIVERS EVOL 2021; 21:691-717. [PMID: 34658667 PMCID: PMC8510888 DOI: 10.1007/s13127-021-00509-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 08/05/2021] [Indexed: 10/31/2022]
Abstract
In the deep sea, the phylogeny and biogeography of only a few taxa have been well studied. Although more than 200 species in 32 genera have been described for the asellote isopod families Desmosomatidae Sars, 1897 and Nannoniscidae Hansen, 1916 from all ocean basins, their phylogenetic relationships are not completely understood. There is little doubt about the close relationship of these families, but the taxonomic position of a number of genera is so far unknown. Based on a combined morphological phylogeny using the Hennigian method with a dataset of 107 described species and a molecular phylogeny based on three markers (COI, 16S, and 18S) with 75 species (most new to science), we could separate Desmosomatidae and Nannoniscidae as separate families. However, we could not support the concept of the subfamilies Eugerdellatinae Hessler, 1970 and Desmosomatinae Hessler, 1970. Most genera of both families were well supported, but several genera appear as para- or even polyphyletic. Within both families, convergent evolution and analogies caused difficulty in defining apomorphies for phylogenetic reconstructions and this is reflected in the results of the concatenated molecular tree. There is no biogeographic pattern in the distribution as the genera occur over the entire Atlantic and Pacific Ocean, showing no specific phylogeographical pattern. Poor resolution at deep desmosomatid nodes may reflect the long evolutionary history of the family and rapid evolutionary radiations. Supplementary Information The online version contains supplementary material available at 10.1007/s13127-021-00509-9.
Collapse
|
12
|
Thompson SP, Kennedy H, Butler BM, Day SJ, Safi E, Evans A. Laboratory exploration of mineral precipitates from Europa's subsurface ocean. J Appl Crystallogr 2021; 54:1455-1479. [PMID: 34667451 PMCID: PMC8493616 DOI: 10.1107/s1600576721008554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 08/17/2021] [Indexed: 11/10/2022] Open
Abstract
The precipitation of hydrated phases from a chondrite-like Na-Mg-Ca-SO4-Cl solution is studied using in situ synchrotron X-ray powder diffraction, under rapid- (360 K h-1, T = 250-80 K, t = 3 h) and ultra-slow-freezing (0.3 K day-1, T = 273-245 K, t = 242 days) conditions. The precipitation sequence under slow cooling initially follows the predictions of equilibrium thermodynamics models. However, after ∼50 days at 245 K, the formation of the highly hydrated sulfate phase Na2Mg(SO4)2·16H2O, a relatively recent discovery in the Na2Mg(SO4)2-H2O system, was observed. Rapid freezing, on the other hand, produced an assemblage of multiple phases which formed within a very short timescale (≤4 min, ΔT = 2 K) and, although remaining present throughout, varied in their relative proportions with decreasing temperature. Mirabilite and meridianiite were the major phases, with pentahydrite, epsomite, hydrohalite, gypsum, blödite, konyaite and loweite also observed. Na2Mg(SO4)2·16H2O was again found to be present and increased in proportion relative to other phases as the temperature decreased. The results are discussed in relation to possible implications for life on Europa and application to other icy ocean worlds.
Collapse
Affiliation(s)
- Stephen P. Thompson
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Hilary Kennedy
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey LL59 5AB, United Kingdom
| | - Benjamin M. Butler
- Environmental and Biochemical Sciences, The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, United Kingdom
| | - Sarah J. Day
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
| | - Emmal Safi
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom
- Astrophysics Group, Lennard-Jones Laboratories, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom
| | - Aneurin Evans
- Astrophysics Group, Lennard-Jones Laboratories, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom
| |
Collapse
|
13
|
Stumpf S, Etches S, Underwood CJ, Kriwet J. Durnonovariaodus maiseyi gen. et sp. nov., a new hybodontiform shark-like chondrichthyan from the Upper Jurassic Kimmeridge Clay Formation of England. PeerJ 2021; 9:e11362. [PMID: 34026354 PMCID: PMC8121075 DOI: 10.7717/peerj.11362] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/06/2021] [Indexed: 11/20/2022] Open
Abstract
A partial skeleton of a hybodontiform shark-like chondrichthyan from the Upper Jurassic Kimmeridge Clay Formation of Dorset, England, is described and designated as a new genus and species, Durnonovariaodus maiseyi gen. et sp. nov. The holotype and only known specimen, which is represented by disarticulated splanchnocranial elements with associated teeth, a single dorsal fin spine, the pelvic girdle, as well as unidentifiable cartilage fragments, plus countless dermal denticles, exhibits a puzzling combination of dental and skeletal features, providing important new insights into the morphological and ecological diversity of hybodontiforms. Durnonovariaodus gen. nov. displays a unique set of dental characters, showing close morphological resemblance to Secarodus from the Middle Jurassic of England, which was erected for distinctive, strongly labio-lingually compressed multicuspid cutting teeth originally described as Hybodus polyprion. Skeletally, Durnonovariaodus gen. nov. resembles Hybodus and Egertonodus in having a palatoquadrate with a palatobasal process and an ethmoidal articular surface, combined with the possession of dorsal fin spines ornamented with costae. Therefore, and given the absence of any conclusive phylogenetic framework, Durnonovariaodus maiseyi gen. et sp. nov. is here tentatively referred to Hybodontidae until more complete material becomes available in order to enable a more reliable suprageneric identification. The holotype of Durnonovariaodus maiseyi gen. et sp. nov. contains two separate pelvic half-girdles, a feature previously considered as evolutionarily primitive among hybodontiforms. However, unfused pelvic half-girdles also occur in the supposedly closely related species Hybodus hauffianus and may in fact have been more widely distributed among hybodontiforms than previously thought, thus rendering the phylogenetic utility of separated pelvic half-girdles for inferring hybodontiform interrelationships difficult and unresolved.
Collapse
Affiliation(s)
- Sebastian Stumpf
- Department of Palaeontology, University of Vienna, Vienna, Austria
| | - Steve Etches
- Museum of Jurassic Marine Life, Kimmeridge, Dorset, United Kingdom
| | - Charlie J Underwood
- School of Earth and Planetary Sciences, Birkbeck College, University of London, London, United Kingdom
| | - Jürgen Kriwet
- Department of Palaeontology, University of Vienna, Vienna, Austria
| |
Collapse
|
14
|
Lü Z, Gong L, Ren Y, Chen Y, Wang Z, Liu L, Li H, Chen X, Li Z, Luo H, Jiang H, Zeng Y, Wang Y, Wang K, Zhang C, Jiang H, Wan W, Qin Y, Zhang J, Zhu L, Shi W, He S, Mao B, Wang W, Kong X, Li Y. Large-scale sequencing of flatfish genomes provides insights into the polyphyletic origin of their specialized body plan. Nat Genet 2021; 53:742-751. [PMID: 33875864 PMCID: PMC8110480 DOI: 10.1038/s41588-021-00836-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 03/05/2021] [Indexed: 11/09/2022]
Abstract
The evolutionary and genetic origins of the specialized body plan of flatfish are largely unclear. We analyzed the genomes of 11 flatfish species representing 9 of the 14 Pleuronectiforme families and conclude that Pleuronectoidei and Psettodoidei do not form a monophyletic group, suggesting independent origins from different percoid ancestors. Genomic and transcriptomic data indicate that genes related to WNT and retinoic acid pathways, hampered musculature and reduced lipids might have functioned in the evolution of the specialized body plan of Pleuronectoidei. Evolution of Psettodoidei involved similar but not identical genes. Our work provides valuable resources and insights for understanding the genetic origins of the unusual body plan of flatfishes.
Collapse
Affiliation(s)
- Zhenming Lü
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Li Gong
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Yandong Ren
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Yongjiu Chen
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Zhongkai Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Liqin Liu
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Haorong Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Xianqing Chen
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Zhenzhu Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Hairong Luo
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Hui Jiang
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Yan Zeng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yifan Wang
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Kun Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Chen Zhang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Haifeng Jiang
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Wenting Wan
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Yanli Qin
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China
| | - Jianshe Zhang
- National Engineering Laboratory of Marine Germplasm Resources Exploration and Utilization, Zhejiang Ocean University, Zhoushan, China
| | - Liang Zhu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Wei Shi
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China
| | - Shunping He
- Key Laboratory of Aquatic Biodiversity and Conservation, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Wen Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China.
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, China.
| | - Xiaoyu Kong
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China.
| | - Yongxin Li
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, China.
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.
| |
Collapse
|
15
|
Berio F, Broyon M, Enault S, Pirot N, López-Romero FA, Debiais-Thibaud M. Diversity and Evolution of Mineralized Skeletal Tissues in Chondrichthyans. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.660767] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The diversity of skeletal tissues in extant vertebrates includes mineralized and unmineralized structures made of bone, cartilage, or tissues of intermediate nature. This variability, together with the diverse nature of skeletal tissues in fossil species question the origin of skeletonization in early vertebrates. In particular, the study of skeletal tissues in cartilaginous fishes is currently mostly restrained to tessellated cartilage, a derived form of mineralized cartilage that evolved at the origin of this group. In this work, we describe the architectural and histological diversity of neural arch mineralization in cartilaginous fishes. The observed variations in the architecture include tessellated cartilage, with or without more massive sites of mineralization, and continuously mineralized neural arches devoid of tesserae. The histology of these various architectures always includes globular mineralization that takes place in the cartilaginous matrix. In many instances, the mineralized structures also include a fibrous component that seems to emerge from the perichondrium and they may display intermediate features, ranging from partly cartilaginous to mostly fibrous matrix, similar to fibrocartilage. Among these perichondrial mineralized tissues is also found, in few species, a lamellar arrangement of the mineralized extracellular matrix. The evolution of the mineralized tissues in cartilaginous fishes is discussed in light of current knowledge of their phylogenetic relationships.
Collapse
|
16
|
Boscolo-Galazzo F, Crichton KA, Ridgwell A, Mawbey EM, Wade BS, Pearson PN. Temperature controls carbon cycling and biological evolution in the ocean twilight zone. Science 2021; 371:1148-1152. [PMID: 33707262 DOI: 10.1126/science.abb6643] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 01/28/2021] [Indexed: 12/16/2022]
Abstract
Theory suggests that the ocean's biological carbon pump, the process by which organic matter is produced at the surface and transferred to the deep ocean, is sensitive to temperature because temperature controls photosynthesis and respiration rates. We applied a combined data-modeling approach to investigate carbon and nutrient recycling rates across the world ocean over the past 15 million years of global cooling. We found that the efficiency of the biological carbon pump increased with ocean cooling as the result of a temperature-dependent reduction in the rate of remineralization (degradation) of sinking organic matter. Increased food delivery at depth prompted the development of new deep-water niches, triggering deep plankton evolution and the expansion of the mesopelagic "twilight zone" ecosystem.
Collapse
Affiliation(s)
| | | | - Andy Ridgwell
- Department of Earth and Planetary Sciences, University of California, Riverside, CA, USA
| | - Elaine M Mawbey
- Department of Earth Sciences, University College London, London, UK
| | - Bridget S Wade
- Department of Earth Sciences, University College London, London, UK
| | - Paul N Pearson
- School of Earth and Environmental Sciences, Cardiff University, Cardiff, UK
| |
Collapse
|
17
|
Evolutionary trends of the conserved neurocranium shape in angel sharks (Squatiniformes, Elasmobranchii). Sci Rep 2020; 10:12582. [PMID: 32724124 PMCID: PMC7387474 DOI: 10.1038/s41598-020-69525-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/19/2020] [Indexed: 11/24/2022] Open
Abstract
Elasmobranchii (i.e., sharks, skates, and rays) forms one of the most diverse groups of marine predators. With a fossil record extending back into the Devonian, several modifications in their body plan illustrate their body shape diversity through time. The angel sharks, whose fossil record dates back to the Late Jurassic, some 160 Ma, have a dorsoventrally flattened body, similar to skates and rays. Fossil skeletons of this group show that the overall morphology was well established earlier in its history. By examining the skull shape of well-preserved fossil material compared to extant angel sharks using geometric morphometric methods, within a phylogenetic framework, we were able to determine the conservative skull shape among angel sharks with a high degree of integration. The morphospace occupation of extant angel sharks is rather restricted, with extensive overlap. Most of the differences in skull shape are related to their geographic distribution patterns. We found higher levels of disparity in extinct forms, but lower ones in extant species. Since angel sharks display a highly specialized prey capture behaviour, we suggest that the morphological integration and biogeographic processes are the main drivers of their diversity, which might limit their capacity to display higher disparities since their origin.
Collapse
|
18
|
Maldonado E, Rangel-Huerta E, Rodriguez-Salazar E, Pereida-Jaramillo E, Martínez-Torres A. Subterranean life: Behavior, metabolic, and some other adaptations of Astyanax cavefish. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 334:463-473. [PMID: 32346998 DOI: 10.1002/jez.b.22948] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 03/25/2020] [Accepted: 04/04/2020] [Indexed: 12/20/2022]
Abstract
The ability of fishes to adapt to any aquatic environment seems limitless. It is enthralling how new species keep appearing at the deep sea or in subterranean environments. There are close to 230 known species of cavefishes, still today the best-known cavefish is Astyanax mexicanus, a Characid that has become a model organism, and has been studied and scrutinized since 1936. There are two morphotypes for A. mexicanus, a surface fish and a cavefish. The surface fish lives in central and northeastern Mexico and south of the United States, while the cavefish is endemic to the "Sierra del Abra-Tanchipa region" in northeast Mexico. The extensive genetic and genomic analysis depicts a complex origin for Astyanax cavefish, with multiple cave invasions and persistent gene flow among cave populations. The surface founder population prevails in the same region where the caves are. In this review, we focus on both morphotype's main morphological and physiological differences, but mainly in recent discoveries about behavioral and metabolic adaptations for subterranean life. These traits may not be as obvious as the troglomorphic characteristics, but are key to understand how Astyanax cavefish thrives in this environment of perpetual darkness.
Collapse
Affiliation(s)
- Ernesto Maldonado
- EvoDevo Research Group, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México
| | - Emma Rangel-Huerta
- EvoDevo Research Group, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México
| | - Elizabeth Rodriguez-Salazar
- EvoDevo Research Group, Unidad de Sistemas Arrecifales, Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México
| | - Elizabeth Pereida-Jaramillo
- Laboratorio de Neurobiología Molecular y Celular, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Santiago de Querétaro, México
| | - Ataulfo Martínez-Torres
- Laboratorio de Neurobiología Molecular y Celular, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Santiago de Querétaro, México
| |
Collapse
|
19
|
Yancey PH. Cellular responses in marine animals to hydrostatic pressure. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 333:398-420. [DOI: 10.1002/jez.2354] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/31/2020] [Accepted: 02/06/2020] [Indexed: 11/08/2022]
Affiliation(s)
- Paul H. Yancey
- Department of BiologyWhitman CollegeWalla Walla Washington
| |
Collapse
|
20
|
Long NP, Farina SC. Enormous gill chambers of deep-sea coffinfishes (Lophiiformes: Chaunacidae) support unique ventilatory specialisations such as breath holding and extreme inflation. JOURNAL OF FISH BIOLOGY 2019; 95:502-509. [PMID: 31073988 DOI: 10.1111/jfb.14003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
Deep sea habitats tend to favor species with low energetic demands, and therefore we predict that deep sea fishes will have behavioral and morphological specializations of the gill ventilatory system to reduce the energetic cost of pumping water across the gills. However, it is difficult to study functional morphology of deep sea fishes due the lack of ability to conduct laboratory experiments with living fishes. For this study, we combined analysis of publicly available video recorded by remote-operated vehicles (ROV) with detailed anatomical study of museum specimens to document the functional morphology of the massive gill chambers that are observed in coffinfishes (Lophiiformes: Chaunacidae). Chaunacids, like other lophiiforms, exhibit highly specialised ventilatory anatomy such as an enlarged branchiostegal apparatus and restricted gill openings, but videos show them using this anatomy in a new and unusual way. We observed eight individuals ventilating extremely slowly at rates of 0.03-0.004 Hz, during which the gill chambers were full yet we saw no inhalation or exhalation for periods of 26 to 245 s. This holding breath behaviour has not been observed in any other fishes and is probably highly energetically efficient. This inflation of the gill chambers also increases body volume by up to 30%, making them more globose and difficult to be taken as prey, much like stomach inflation in pufferfishes (Tetraodontidae). We also used micro computed-tomography (CT) scans to document the enormous branchiostegal rays and associated muscles that support this unique behaviour.
Collapse
Affiliation(s)
- Nicholas P Long
- Department of Biology, Dickinson College, Carlisle, Pennsylvania, USA
| | - Stacy C Farina
- Department of Biology, Howard University, Washington, District of Columbia, USA
| |
Collapse
|
21
|
Ma J, Song J, Li X, Yuan H, Li N, Duan L, Wang Q. Environmental characteristics in three seamount areas of the Tropical Western Pacific Ocean: Focusing on nutrients. MARINE POLLUTION BULLETIN 2019; 143:163-174. [PMID: 31789152 DOI: 10.1016/j.marpolbul.2019.04.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/12/2019] [Accepted: 04/16/2019] [Indexed: 06/10/2023]
Abstract
Nutrients distribution and influencing factors in three seamount areas named Y3, M2 and C4 of the Tropical Western Pacific Ocean (TWPO) were investigated. Nutrients showed obvious uplifts around the three seamounts, consistent with the uplifts of isotherms and isohalines, indicating the existence of a bottom-up process of nutrients. Meanwhile, compared with the stations away from seamount and the reference stations in the TWPO, nutrients concentrations around seamount were much higher. Among the three seamounts, the average nutrients concentrations were highest in Y3, while they were lowest in C4. Moreover, compared with the obvious nitrogen limitation in Y3 and M2, the N:P (13.5:1) and Si:N (6.1:1) were closed to the Redfield ratio. The current-seamount interaction was the determining influencing factor on nutrients distribution, causing the hydrology dynamic changes such as uplifts and Taylor column. Meanwhile, T and S also affected nutrients distribution, especially nutrients and T showed significant negative correlations.
Collapse
Affiliation(s)
- Jun Ma
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Jinming Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Xuegang Li
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Huamao Yuan
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Ning Li
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Liqin Duan
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Qidong Wang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Function Laboratory of Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| |
Collapse
|
22
|
Abstract
Deep-sea trenches, depths 6000-11,000 m, are characterized by high pressures, low temperatures, and absence of sunlight. These features make up the majority of the deepest marine habitat-the hadal zone-home to distinct communities from those in the surrounding abyssal plains. The snailfishes, family Liparidae (Scorpaeniformes), have found notable success in the hadal zone from ∼6000 to 8200 m, comprising the dominant ichthyofauna in at least six trenches worldwide. The hadal fish community is distinct from the abyssal community where elongate, scavenging fishes such as rattails (Macrouridae), cutthroat eels (Synaphobranchidae), tripodfishes (Ipnopidae), eelpouts (Zoarcidae), and cusk eels (Ophidiidae) are most common. Until recently, little was known about the biology of these deepest-living fishes, or the factors that drive their success at hadal depths. Here, I review recent investigations spanning the abyssal-hadal boundary and discuss the factors structuring these communities, including the roles of pressure adaptation, feeding ecology, and life history. Hadal fishes show specialized adaptation to hydrostatic pressure both in accumulation of the pressure-counteractant trimethylamine n-oxide and in intrinsic changes to enzymes. Stomach content and amino acid isotope analyses, and jaw morphology suggest that suction-feeding predatory fishes like hadal liparids may find an advantage to descending into the trench where amphipods are increasingly abundant. Analysis of otolith growth zones suggest that snailfishes may be adapted to a seismically active, high-disturbance hadal environment by having relatively short life-spans. This review synthesizes the known literature on the planet's deepest-living fishes and informs new understanding of adaptations to life in the trenches.
Collapse
Affiliation(s)
- M E Gerringer
- Friday Harbor Laboratories, University of Washington, Friday Harbor, WA 98250, USA
| |
Collapse
|
23
|
Lemaire B. Hydrostatic pressure and the experimental toxicology of marine fishes: The elephant in the room. MARINE POLLUTION BULLETIN 2017; 124:206-210. [PMID: 28739107 DOI: 10.1016/j.marpolbul.2017.07.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/10/2017] [Accepted: 07/11/2017] [Indexed: 06/07/2023]
Abstract
Hydrostatic pressure (HP) increases linearly with depth in aquatic environments, so that many fish species routinely experience moderate-to-high HP levels (i.e., from a few to dozens of MPa). Biological effects of this thermodynamic variable are evidenced by a reduced functionality of many biomolecular systems, even in barotolerant and barophilic species. It is likely that environmentally-relevant HP levels (i.e., above atmospheric) could also modulate the responsiveness to and toxic effects of pollutants in fish. Still, only a few laboratories have investigated this possibility. The already-published ecobarotoxicological studies have brought strong support to the notion that HP can indeed modulate pollutant response in shallow-water and deep-sea animals. A careful reassessment of toxicity responses is therefore required. To quantify the exact influence of HP in marine fish toxicology, a research framework is proposed that should ensure the collection of meaningful data for risk assessment, using standard toxicity testing and mechanistic approaches.
Collapse
Affiliation(s)
- Benjamin Lemaire
- Institut des Sciences de la Vie, Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium.
| |
Collapse
|
24
|
|
25
|
Solbakken MH, Voje KL, Jakobsen KS, Jentoft S. Linking species habitat and past palaeoclimatic events to evolution of the teleost innate immune system. Proc Biol Sci 2017; 284:20162810. [PMID: 28446692 PMCID: PMC5413918 DOI: 10.1098/rspb.2016.2810] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/21/2017] [Indexed: 12/14/2022] Open
Abstract
Host-intrinsic factors as well as environmental changes are known to be strong evolutionary drivers defining the genetic foundation of immunity. Using a novel set of teleost genomes and a time-calibrated phylogeny, we here investigate the family of Toll-like receptor (TLR) genes and address the underlying evolutionary processes shaping the diversity of the first-line defence. Our findings reveal remarkable flexibility within the evolutionary design of teleost innate immunity characterized by prominent TLR gene losses and expansions. In the order of Gadiformes, expansions correlate with the loss of major histocompatibility complex class II (MHCII) and diversifying selection analyses support that this has fostered new immunological innovations in TLRs within this lineage. In teleosts overall, TLRs expansions correlate with species latitudinal distributions and maximum depth. By contrast, lineage-specific gene losses overlap with well-described changes in palaeoclimate (global ocean anoxia) and past Atlantic Ocean geography. In conclusion, we suggest that the evolvability of the teleost immune system has most likely played a prominent role in the survival and successful radiation of this lineage.
Collapse
Affiliation(s)
- Monica Hongrø Solbakken
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
| | - Kjetil Lysne Voje
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
| | - Kjetill Sigurd Jakobsen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
| | - Sissel Jentoft
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, PO Box 1066, Blindern, 0316 Oslo, Norway
- Department of Natural Sciences, University of Agder, Kristiansand, Norway
| |
Collapse
|
26
|
Djurhuus A, Boersch-Supan PH, Mikalsen SO, Rogers AD. Microbe biogeography tracks water masses in a dynamic oceanic frontal system. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170033. [PMID: 28405400 PMCID: PMC5383857 DOI: 10.1098/rsos.170033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 02/14/2017] [Indexed: 05/11/2023]
Abstract
Dispersal limitation, not just environmental selection, plays an important role in microbial biogeography. The distance-decay relationship is thought to be weak in habitats where dispersal is high, such as in the pelagic environment, where ocean currents facilitate microbial dispersal. Most studies of microbial community composition to date have observed little geographical heterogeneity on a regional scale (100 km). We present a study of microbial communities across a dynamic frontal zone in the southwest Indian Ocean and investigate the spatial structure of the microbes with respect to the different water masses separated by these fronts. We collected 153 samples of free-living microorganisms from five seamounts located along a gradient from subtropical to subantarctic waters and across three depth layers: (i) the sub-surface chlorophyll maximum (approx. 40 m), (ii) the bottom of the euphotic zone (approx. 200 m), and (iii) the benthic boundary layer (300-2000 m). Diversity and abundance of microbial operational taxonomic units (OTUs) were assessed by amplification and sequencing of the 16S rRNA gene on an Illumina MiSeq platform. Multivariate analyses showed that microbial communities were structured more strongly by depth than by latitude, with similar phyla occurring within each depth stratum across seamounts. The deep layer was homogeneous across the entire survey area, corresponding to the spread of Antarctic intermediate water. However, within both the sub-surface layer and the intermediate depth stratum there was evidence for OTU turnover across fronts. The microbiome of these layers appears to be divided into three distinct biological regimes corresponding to the subantarctic surface water, the convergence zone and subtropical. We show that microbial biogeography across depth and latitudinal gradients is linked to the water masses the microbes persist in, resulting in regional patterns of microbial biogeography that correspond to the regional scale physical oceanography.
Collapse
Affiliation(s)
- Anni Djurhuus
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
- College of Marine Science, University of South Florida, 830 1st St SE, St Petersburg, FL 33701, USA
- Author for correspondence: Anni Djurhuus e-mail:
| | - Philipp H. Boersch-Supan
- Department of Integrative Biology, University of South Florida, 4202 E Fowler Avenue, Tampa, FL 33620, USA
- Department of Geography, University of Florida, Gainesville, FL 32611, USA
| | - Svein-Ole Mikalsen
- Department of Science and Technology, University of the Faroe Islands, Noatun 3, Torshavn, Faroe Islands
| | - Alex D. Rogers
- Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK
| |
Collapse
|
27
|
Solbakken MH, Rise ML, Jakobsen KS, Jentoft S. Successive Losses of Central Immune Genes Characterize the Gadiformes' Alternate Immunity. Genome Biol Evol 2016; 8:3508-3515. [PMID: 27797950 PMCID: PMC5203787 DOI: 10.1093/gbe/evw250] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2016] [Indexed: 12/22/2022] Open
Abstract
Great genetic variability among teleost immunomes, with gene losses and expansions of central adaptive and innate components, has been discovered through genome sequencing over the last few years. Here, we demonstrate that the innate Myxovirus resistance gene (Mx) is lost from the ancestor of Gadiformes and the closely related Stylephorus chordatus, thus predating the loss of Major Histocompatibility Complex class II (MHCII) in Gadiformes. Although the functional implication of Mx loss is still unknown, we demonstrate that this loss is one of several ancient events appearing in successive order throughout the evolution of teleost immunity. In particular, we find that the loss of Toll-like receptor 5 predates the loss of Mx involving the entire Paracanthopterygii lineage. Using a time-calibrated phylogeny, we show that loss of MHCII and Mx overlap with major paleoclimatic and geological events indicating that these genetic changes were adaptive responses to the changing environment at the time.
Collapse
Affiliation(s)
- Monica H Solbakken
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Kjetill S Jakobsen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Sissel Jentoft
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
- Department of Natural Sciences, University of Agder, Kristiansand, Norway
| |
Collapse
|
28
|
Gaither MR, Violi B, Gray HW, Neat F, Drazen JC, Grubbs RD, Roa-Varón A, Sutton T, Hoelzel AR. Depth as a driver of evolution in the deep sea: Insights from grenadiers (Gadiformes: Macrouridae) of the genus Coryphaenoides. Mol Phylogenet Evol 2016; 104:73-82. [DOI: 10.1016/j.ympev.2016.07.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 07/12/2016] [Accepted: 07/25/2016] [Indexed: 11/26/2022]
|
29
|
Mindel BL, Neat FC, Trueman CN, Webb TJ, Blanchard JL. Functional, size and taxonomic diversity of fish along a depth gradient in the deep sea. PeerJ 2016; 4:e2387. [PMID: 27672494 PMCID: PMC5028789 DOI: 10.7717/peerj.2387] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 07/31/2016] [Indexed: 11/20/2022] Open
Abstract
Biodiversity is well studied in ecology and the concept has been developed to include traits of species, rather than solely taxonomy, to better reflect the functional diversity of a system. The deep sea provides a natural environmental gradient within which to study changes in different diversity metrics, but traits of deep-sea fish are not widely known, hampering the application of functional diversity to this globally important system. We used morphological traits to determine the functional richness and functional divergence of demersal fish assemblages along the continental slope in the Northeast Atlantic, at depths of 300-2,000 m. We compared these metrics to size diversity based on individual body size and species richness. Functional richness and size diversity showed similar patterns, with the highest diversity at intermediate depths; functional divergence showed the opposite pattern, with the highest values at the shallowest and deepest parts of the study site. Species richness increased with depth. The functional implications of these patterns were deduced by examining depth-related changes in morphological traits and the dominance of feeding guilds as illustrated by stable isotope analyses. The patterns in diversity and the variation in certain morphological traits can potentially be explained by changes in the relative dominance of pelagic and benthic feeding guilds. All measures of diversity examined here suggest that the deep areas of the continental slope may be equally or more diverse than assemblages just beyond the continental shelf.
Collapse
Affiliation(s)
- Beth L. Mindel
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Francis C. Neat
- Marine Scotland, The Scottish Government, Aberdeen, United Kingdom
| | - Clive N. Trueman
- Ocean and Earth Science, University of Southampton, Southampton, United Kingdom
| | - Thomas J. Webb
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Julia L. Blanchard
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| |
Collapse
|
30
|
Casane D, Rétaux S. Evolutionary Genetics of the Cavefish Astyanax mexicanus. ADVANCES IN GENETICS 2016; 95:117-59. [PMID: 27503356 DOI: 10.1016/bs.adgen.2016.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Blind and depigmented fish belonging to the species Astyanax mexicanus are outstanding models for evolutionary genetics. During their evolution in the darkness of caves, they have undergone a number of changes at the morphological, physiological, and behavioral levels, but they can still breed with their river-dwelling conspecifics. The fertile hybrids between these two morphotypes allow forward genetic approaches, from the search of quantitative trait loci to the identification of the mutations underlying the evolution of troglomorphism. We review here the past 30years of evolutionary genetics on Astyanax: from the first crosses and the discovery of convergent evolution of different Astyanax cavefish populations to the most recent evolutionary transcriptomics and genomics studies that have provided researchers with potential candidate genes to be tested using functional genetic approaches. Although significant progress has been made and some genes have been identified, cavefish have not yet fully revealed the secret of their adaptation to the absence of light. In particular, the genetic determinism of their loss of eyes seems complex and still puzzles researchers. We also discuss future research directions, including searches for the origin of cave alleles and searches for selection genome-wide, as well as the necessary but missing information on the timing of cave colonization by surface fish.
Collapse
Affiliation(s)
- D Casane
- Laboratory EGCE, CNRS and University of Paris-Sud, Gif-sur-Yvette, France; Paris Diderot University, Sorbonne Paris Cité, France
| | - S Rétaux
- Paris-Saclay Institute of Neuroscience, CNRS and University Paris-Sud, Gif-sur-Yvette, France
| |
Collapse
|
31
|
Yancey PH, Siebenaller JF. Co-evolution of proteins and solutions: protein adaptation versus cytoprotective micromolecules and their roles in marine organisms. ACTA ACUST UNITED AC 2016; 218:1880-96. [PMID: 26085665 DOI: 10.1242/jeb.114355] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Organisms experience a wide range of environmental factors such as temperature, salinity and hydrostatic pressure, which pose challenges to biochemical processes. Studies on adaptations to such factors have largely focused on macromolecules, especially intrinsic adaptations in protein structure and function. However, micromolecular cosolutes can act as cytoprotectants in the cellular milieu to affect biochemical function and they are now recognized as important extrinsic adaptations. These solutes, both inorganic and organic, have been best characterized as osmolytes, which accumulate to reduce osmotic water loss. Singly, and in combination, many cosolutes have properties beyond simple osmotic effects, e.g. altering the stability and function of proteins in the face of numerous stressors. A key example is the marine osmolyte trimethylamine oxide (TMAO), which appears to enhance water structure and is excluded from peptide backbones, favoring protein folding and stability and counteracting destabilizers like urea and temperature. Co-evolution of intrinsic and extrinsic adaptations is illustrated with high hydrostatic pressure in deep-living organisms. Cytosolic and membrane proteins and G-protein-coupled signal transduction in fishes under pressure show inhibited function and stability, while revealing a number of intrinsic adaptations in deep species. Yet, intrinsic adaptations are often incomplete, and those fishes accumulate TMAO linearly with depth, suggesting a role for TMAO as an extrinsic 'piezolyte' or pressure cosolute. Indeed, TMAO is able to counteract the inhibitory effects of pressure on the stability and function of many proteins. Other cosolutes are cytoprotective in other ways, such as via antioxidation. Such observations highlight the importance of considering the cellular milieu in biochemical and cellular adaptation.
Collapse
Affiliation(s)
- Paul H Yancey
- Department of Biology, Whitman College, Walla Walla, WA 99362, USA
| | - Joseph F Siebenaller
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| |
Collapse
|
32
|
Treberg JR, Speers-Roesch B. Does the physiology of chondrichthyan fishes constrain their distribution in the deep sea? J Exp Biol 2016; 219:615-25. [DOI: 10.1242/jeb.128108] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The deep sea is the largest ecosystem on Earth but organisms living there must contend with high pressure, low temperature, darkness and scarce food. Chondrichthyan fishes (sharks and their relatives) are important consumers in most marine ecosystems but are uncommon deeper than 3000 m and exceedingly rare, or quite possibly absent, from the vast abyss (depths >4000 m). By contrast, teleost (bony) fishes are commonly found to depths of ∼8400 m. Why chondrichthyans are scarce at abyssal depths is a major biogeographical puzzle. Here, after outlining the depth-related physiological trends among chondrichthyans, we discuss several existing and new hypotheses that implicate unique physiological and biochemical characteristics of chondrichthyans as potential constraints on their depth distribution. We highlight three major, and not mutually exclusive, working hypotheses: (1) the urea-based osmoregulatory strategy of chondrichthyans might conflict with the interactive effects of low temperature and high pressure on protein and membrane function at great depth; (2) the reliance on lipid accumulation for buoyancy in chondrichthyans has a unique energetic cost, which might increasingly limit growth and reproductive output as food availability decreases with depth; (3) their osmoregulatory strategy may make chondrichthyans unusually nitrogen limited, a potential liability in the food-poor abyss. These hypotheses acting in concert could help to explain the scarcity of chondrichthyans at great depths: the mechanisms of the first hypothesis may place an absolute, pressure-related depth limit on physiological function, while the mechanisms of the second and third hypotheses may limit depth distribution by constraining performance in the oligotrophic abyss, in ways that preclude the establishment of viable populations or lead to competitive exclusion by teleosts.
Collapse
Affiliation(s)
- Jason R. Treberg
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
- Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
| | - Ben Speers-Roesch
- Department of Ocean Sciences, Memorial University of Newfoundland, St John's, Newfoundland, Canada A1C 5S7
| |
Collapse
|
33
|
Yancey PH, Gerringer ME, Drazen JC, Rowden AA, Jamieson A. Marine fish may be biochemically constrained from inhabiting the deepest ocean depths. Proc Natl Acad Sci U S A 2014; 111:4461-5. [PMID: 24591588 PMCID: PMC3970477 DOI: 10.1073/pnas.1322003111] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
No fish have been found in the deepest 25% of the ocean (8,400-11,000 m). This apparent absence has been attributed to hydrostatic pressure, although direct evidence is wanting because of the lack of deepest-living species to study. The common osmolyte trimethylamine N-oxide (TMAO) stabilizes proteins against pressure and increases with depth, going from 40 to 261 mmol/kg in teleost fishes from 0 to 4,850 m. TMAO accumulation with depth results in increasing internal osmolality (typically 350 mOsmol/kg in shallow species compared with seawater's 1,100 mOsmol/kg). Preliminary extrapolation of osmolalities of predicted isosmotic state at 8,000-8,500 m may indicate a possible physiological limit, as greater depths would require reversal of osmotic gradients and, thus, osmoregulatory systems. We tested this prediction by capturing five of the second-deepest known fish, the hadal snailfish (Notoliparis kermadecensis; Liparidae), from 7,000 m in the Kermadec Trench. We found their muscles to have a TMAO content of 386 ± 18 mmol/kg and osmolality of 991 ± 22 mOsmol/kg. These data fit previous extrapolations and, combined with new osmolalities from bathyal and abyssal fishes, predict isosmotic state at 8,200 m. This is previously unidentified evidence that biochemistry could constrain the depth of a large, complex taxonomic group.
Collapse
Affiliation(s)
- Paul H. Yancey
- Biology Department, Whitman College, Walla Walla, WA 99362
| | - Mackenzie E. Gerringer
- Biology Department, Whitman College, Walla Walla, WA 99362
- Department of Oceanography, University of Hawaii, Honolulu, HI 96822
| | - Jeffrey C. Drazen
- Department of Oceanography, University of Hawaii, Honolulu, HI 96822
| | - Ashley A. Rowden
- National Institute of Water and Atmospheric Research, Wellington 6021, New Zealand; and
| | - Alan Jamieson
- Oceanlab, Institute of Biological and Environmental Sciences, University of Aberdeen, Newburgh, Aberdeenshire AB41 6AA, United Kingdom
| |
Collapse
|