1
|
Abe S, Takahata Y, Miyakawa H. Daphnia uses its circadian clock for short-day recognition in environmental sex determination. Curr Biol 2024; 34:2002-2010.e3. [PMID: 38579713 DOI: 10.1016/j.cub.2024.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 02/12/2024] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Some organisms have developed a mechanism called environmental sex determination (ESD), which allows environmental cues, rather than sex chromosomes or genes, to determine offspring sex.1,2,3,4 ESD is advantageous to optimize sex ratios according to environmental conditions, enhancing reproductive success.5,6 However, the process by which organisms perceive and translate diverse environmental signals into offspring sex remains unclear. Here, we analyzed the environmental perception mechanism in the crustacean, Daphnia pulex, a seasonal (photoperiodic) ESD arthropod, capable of producing females under long days and males under short days.7,8,9,10 Through breeding experiments, we found that their circadian clock likely contributes to perception of day length. To explore this further, we created a genetically modified daphnid by knocking out the clock gene, period, using genome editing. Knockout disrupted the daphnid's ability to sustain diel vertical migration (DVM) under constant darkness, driven by the circadian clock, and leading them to produce females regardless of day length. Additionally, when exposed to an analog of juvenile hormone (JH), an endocrine factor synthesized in mothers during male production, or subjected to unfavorable conditions of high density and low food availability, these knockout daphnids produced males regardless of day length, like wild-type daphnids. Based on these findings, we propose that recognizing short days via the circadian clock is the initial step in sex determination. This recognition subsequently triggers male production by signaling the endocrine system, specifically via the JH signal. Establishment of a connection between these two processes may be the crucial element in evolution of ESD in Daphnia.
Collapse
Affiliation(s)
- Shione Abe
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Yugo Takahata
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | - Hitoshi Miyakawa
- Center for Bioscience Research and Education, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan.
| |
Collapse
|
2
|
Timmins-Schiffman E, Maas AE, Khanna R, Blanco-Bercial L, Huang E, Nunn BL. Removal of Exogenous Stimuli Reveals a Canalization of Circadian Physiology in a Vertically Migrating Copepod. J Proteome Res 2024. [PMID: 38690632 DOI: 10.1021/acs.jproteome.4c00086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Diel rhythms are observed across taxa and are important for maintaining synchrony between the environment and organismal physiology. A striking example of this is the diel vertical migration undertaken by zooplankton, some of which, such as the 5 mm-long copepod Pleuromamma xiphias (P. xiphias), migrate hundreds of meters daily between the surface ocean and deeper waters. Some of the molecular pathways that underlie the expressed phenotype at different stages of this migration are entrained by environmental variables (e.g., day length and food availability), while others are regulated by internal clocks. We identified a series of proteomic biomarkers that vary across ocean DVM and applied them to copepods incubated in 24 h of darkness to assess circadian control. The dark-incubated copepods shared some proteomic similarities to the ocean-caught copepods (i.e., increased abundance of carbohydrate metabolism proteins at night). Shipboard-incubated copepods demonstrated a clearer distinction between night and day proteomic profiles, and more proteins were differentially abundant than in the in situ copepods, even in the absence of the photoperiod and other environmental cues. This pattern suggests that there is a canalization of rhythmic diel physiology in P. xiphias that reflects likely circadian clock control over diverse molecular pathways.
Collapse
Affiliation(s)
- Emma Timmins-Schiffman
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| | - Amy E Maas
- Bermuda Institute of Ocean Sciences, Arizona State University, St. George's 98C3+8F, Bermuda
| | - Rayhan Khanna
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
- Cornell University, Ithaca, New York 14850, United States
| | - Leocadio Blanco-Bercial
- Bermuda Institute of Ocean Sciences, Arizona State University, St. George's 98C3+8F, Bermuda
| | - Eric Huang
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
- Just-Evotec Biologics, Seattle, Washington 98109, United States
| | - Brook L Nunn
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, United States
| |
Collapse
|
3
|
Steinberg DK, Stamieszkin K, Maas AE, Durkin CA, Passow U, Estapa ML, Omand MM, McDonnell AMP, Karp‐Boss L, Galbraith M, Siegel DA. The Outsized Role of Salps in Carbon Export in the Subarctic Northeast Pacific Ocean. Global Biogeochem Cycles 2023; 37:e2022GB007523. [PMID: 37034114 PMCID: PMC10078299 DOI: 10.1029/2022gb007523] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 06/19/2023]
Abstract
Periodic blooms of salps (pelagic tunicates) can result in high export of organic matter, leading to an "outsized" role in the ocean's biological carbon pump (BCP). However, due to their episodic and patchy nature, salp blooms often go undetected and are rarely included in measurements or models of the BCP. We quantified salp-mediated export processes in the northeast subarctic Pacific Ocean in summer of 2018 during a bloom of Salpa aspera. Salps migrated from 300 to 750 m during the day into the upper 100 m at night. Salp fecal pellet production comprised up to 82% of the particulate organic carbon (POC) produced as fecal pellets by the entire epipelagic zooplankton community. Rapid sinking velocities of salp pellets (400-1,200 m d-1) and low microbial respiration rates on pellets (<1% of pellet C respired day-1) led to high salp pellet POC export from the euphotic zone-up to 48% of total sinking POC across the 100 m depth horizon. Salp active transport of carbon by diel vertical migration and carbon export from sinking salp carcasses was usually <10% of the total sinking POC flux. Salp-mediated export markedly increased BCP efficiency, increasing by 1.5-fold the proportion of net primary production exported as POC across the base of the euphotic zone and by 2.6-fold the proportion of this POC flux persisting 100 m below the euphotic zone. Salps have unique and important effects on ocean biogeochemistry and, especially in low flux settings, can dramatically increase BCP efficiency and thus carbon sequestration.
Collapse
Affiliation(s)
- Deborah K. Steinberg
- Department of Biological SciencesVirginia Institute of Marine ScienceWilliam & MaryGloucester PointVAUSA
| | - Karen Stamieszkin
- Department of Biological SciencesVirginia Institute of Marine ScienceWilliam & MaryGloucester PointVAUSA
- Bigelow Laboratory for Ocean SciencesEast BoothbayMEUSA
| | - Amy E. Maas
- Bermuda Institute of Ocean SciencesSt. George'sBermuda
| | | | - Uta Passow
- Ocean SciencesMemorial University of NewfoundlandSt John'sNLCanada
| | - Margaret L. Estapa
- School of Marine SciencesDarling Marine CenterUniversity of MaineWalpoleMEUSA
| | - Melissa M. Omand
- Graduate School of OceanographyUniversity of Rhode IslandNarragansettRIUSA
| | | | - Lee Karp‐Boss
- School of Marine SciencesUniversity of MaineOronoMEUSA
| | - Moira Galbraith
- Department of Fisheries and OceansInstitute of Ocean SciencesSidneyBCCanada
| | - David A. Siegel
- Earth Research Institute and Department of GeographyUniversity of California Santa BarbaraSanta BarbaraCAUSA
| |
Collapse
|
4
|
Pastor-Prieto M, SabatÉs A, Raya V, Canepa A, Parraguez TI, Gili JM. The role of oceanographic conditions and colony size in shaping the spatial structure of Pyrosoma atlanticum in the NW Mediterranean Sea. J Plankton Res 2022; 44:984-999. [PMID: 36447781 PMCID: PMC9692197 DOI: 10.1093/plankt/fbac056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
This study investigates the role of winter oceanographic conditions on the horizontal and vertical spatial structure of Pyrosoma atlanticum at different ontogenetic stages. Data were obtained on two oceanographic cruises (February 2017 and 2018) in the NW Mediterranean. Small colonies were exceptionally abundant in 2017, linked to an earlier development of spring conditions and the subsequent seasonal phytoplankton bloom. The mesoscale distribution of P. atlanticum differed depending on the colony size. Large colonies (≥7 mm) were found on the slope all along the density front, whereas small (<4 mm) and medium colonies (4-6.9 mm) extended their distribution over the shelf because of instabilities of the front, and were mostly absent in the cold, low-salinity coastal waters. The analysis of their vertical distribution showed that at night colonies of all sizes remained close to the surface, where chlorophyll-a levels were high, whereas during the day they migrated to deeper layers, reaching greater depths as the colony size increased. The migratory behaviour started when colonies were 4-6.9 mm long. The relative importance of the species in the downward carbon transport is discussed. Our results highlight the need to further study the ecology of this efficient filter feeder in the Mediterranean.
Collapse
Affiliation(s)
| | - Ana SabatÉs
- Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta, 37-49, Barcelona 08003, Spain
| | - Vanesa Raya
- Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta, 37-49, Barcelona 08003, Spain
| | - Antonio Canepa
- Departamento de Ingeniería Informática, Escuela Politécnica Superior, Universidad de Burgos, Avda. Cantabria, Burgos 09006, Spain
| | - TomÁs I Parraguez
- Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta, 37-49, Barcelona 08003, Spain
| | - Josep-Maria Gili
- Institut de Ciències del Mar (ICM-CSIC), Passeig Marítim de la Barceloneta, 37-49, Barcelona 08003, Spain
| |
Collapse
|
5
|
Shima JS, Osenberg CW, Alonzo SH, Noonburg EG, Swearer SE. How moonlight shapes environments, life histories, and ecological interactions on coral reefs. Emerg Top Life Sci 2022:ETLS20210231. [PMID: 35019136 DOI: 10.1042/ETLS20210237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 12/05/2021] [Accepted: 12/17/2021] [Indexed: 11/17/2022]
Abstract
The lunar cycle drives variation in nocturnal brightness. For the epipelagic larvae of coral reef organisms, nocturnal illumination may have widespread and underappreciated consequences. At sea, the onset of darkness coincides with an influx of mesopelagic organisms to shallow water (i.e. 'diel vertical migrants') that include predators (e.g. lanternfishes) and prey (zooplankton) of zooplanktivorous coral reef larvae. Moonlight generally suppresses this influx, but lunar periodicity in the timing and intensity of nocturnal brightness may affect vertically migrating predators and prey differently. A major turnover of species occurs at sunset on the reef, with diurnal species seeking shelter and nocturnal species emerging to hunt. The hunting ability of nocturnal reef-based predators is aided by the light of the moon. Consequently, variation in nocturnal illumination is likely to shape the timing of reproduction, larval development, and settlement for many coral reef organisms. This synthesis underscores the potential importance of trophic linkages between coral reefs and adjacent pelagic ecosystems, facilitated by the diel migrations of mesopelagic organisms and the ontogenetic migrations of coral reef larvae. Research is needed to better understand the effects of lunar cycles on life-history strategies, and the potentially disruptive effects of light pollution, turbidity, and climate-driven changes to nocturnal cloud cover. These underappreciated threats may alter patterns of nocturnal illumination that have shaped the evolutionary history of many coral reef organisms, with consequences for larval survival and population replenishment that could rival or exceed other effects arising from climate change.
Collapse
|
6
|
Schnell NK, Kriwet J, López-Romero FA, Lecointre G, Pfaff C. Musculotendinous system of mesopelagic fishes: Stomiiformes (Teleostei). J Anat 2021; 240:1095-1126. [PMID: 34927245 DOI: 10.1111/joa.13614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 12/06/2021] [Accepted: 12/06/2021] [Indexed: 11/28/2022] Open
Abstract
Every night the greatest migration on Earth starts in the deep pelagic oceans where organisms move up to the meso- and epipelagic to find food and return to the deeper zones during the day. One of the dominant fish taxa undertaking vertical migrations are the dragonfishes (Stomiiformes). However, the functional aspects of locomotion and the architecture of the musculotendinous system (MTS) in these fishes have never been examined. In general, the MTS is organized in segmented blocks of specific three-dimensional 'W-shaped' foldings, the myomeres, separated by thin sheets of connective tissue, the myosepta. Within a myoseptum characteristic intermuscular bones or tendons may be developed. Together with the fins, the MTS forms the functional unit for locomotion in fishes. For this study, microdissections of cleared and double stained specimens of seven stomiiform species (Astronesthes sp., Chauliodus sloani, Malacosteus australis, Eustomias simplex, Polymetme sp., Sigmops elongatus, Argyropelecus affinis) were conducted to investigate their MTS. Soft tissue was investigated non-invasively in E. schmidti using a micro-CT scan of one specimen stained with iodine. Additionally, classical histological serial sections were consulted. The investigated stomiiforms are characterized by the absence of anterior cones in the anteriormost myosepta. These cones are developed in myosepta at the level of the dorsal fin and elongate gradually in more posterior myosepta. In all but one investigated stomiiform taxon the horizontal septum is reduced. The amount of connective tissue in the myosepta is very low anteriorly, but increases gradually with body length. Red musculature overlies laterally the white musculature and exhibits strong tendons in each myomere within the muscle bundles dorsal and ventral to the horizontal midline. The amount of red musculature increases immensely towards the caudal fin. The elongated lateral tendons of the posterior body segments attach in a highly complex pattern on the caudal-fin rays, which indicates that the posterior most myosepta are equipped for a multisegmental force transmission towards the caudal fin. This unique anatomical condition might be essential for steady swimming during diel vertical migrations, when prey is rarely available.
Collapse
Affiliation(s)
- Nalani K Schnell
- Institut Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, SU, EPHE, UA, Concarneau, France
| | - Jürgen Kriwet
- Department of Palaeontology, University of Vienna, Vienna, Austria
| | | | - Guillaume Lecointre
- Institut Systématique, Evolution, Biodiversité (ISYEB), Muséum national d'Histoire naturelle, CNRS, SU, EPHE, UA, Paris, France
| | - Cathrin Pfaff
- Department of Palaeontology, University of Vienna, Vienna, Austria
| |
Collapse
|
7
|
Abstract
Circadian rhythms enable organisms to mediate their molecular and physiological processes with changes in their environment. Although feeding behavior directly affects within-organism processes, there are few examples of a circadian rhythm in this key behavior. Here, we show that Daphnia have a nocturnal circadian rhythm in feeding behavior that corresponds with their diel vertical migration (DVM), an important life history strategy for predator and UV avoidance. In addition, this feeding rhythm appears to be temperature compensated, which suggests that feeding behavior is robust to seasonal changes in water temperature. A circadian rhythm in feeding behavior can impact energetically demanding processes like metabolism and immunity, which may have drastic effects on susceptibility to disease, starvation risk, and ultimately, fitness.
Collapse
Affiliation(s)
| | - Kristina Amato
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska
| | - Clayton E Cressler
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska
| |
Collapse
|
8
|
Bandara K, Varpe Ø, Wijewardene L, Tverberg V, Eiane K. Two hundred years of zooplankton vertical migration research. Biol Rev Camb Philos Soc 2021; 96:1547-1589. [PMID: 33942990 DOI: 10.1111/brv.12715] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 01/01/2023]
Abstract
Vertical migration is a geographically and taxonomically widespread behaviour among zooplankton that spans across diel and seasonal timescales. The shorter-term diel vertical migration (DVM) has a periodicity of up to 1 day and was first described by the French naturalist Georges Cuvier in 1817. In 1888, the German marine biologist Carl Chun described the longer-term seasonal vertical migration (SVM), which has a periodicity of ca. 1 year. The proximate control and adaptive significance of DVM have been extensively studied and are well understood. DVM is generally a behaviour controlled by ambient irradiance, which allows herbivorous zooplankton to feed in food-rich shallower waters during the night when light-dependent (visual) predation risk is minimal and take refuge in deeper, darker waters during daytime. However, DVMs of herbivorous zooplankton are followed by their predators, producing complex predator-prey patterns that may be traced across multiple trophic levels. In contrast to DVM, SVM research is relatively young and its causes and consequences are less well understood. During periods of seasonal environmental deterioration, SVM allows zooplankton to evacuate shallower waters seasonally and take refuge in deeper waters often in a state of dormancy. Both DVM and SVM play a significant role in the vertical transport of organic carbon to deeper waters (biological carbon sequestration), and hence in the buffering of global climate change. Although many animal migrations are expected to change under future climate scenarios, little is known about the potential implications of global climate change on zooplankton vertical migrations and its impact on the biological carbon sequestration process. Further, the combined influence of DVM and SVM in determining zooplankton fitness and maintenance of their horizontal (geographic) distributions is not well understood. The contrasting spatial (deep versus shallow) and temporal (diel versus seasonal) scales over which these two migrations occur lead to challenges in studying them at higher spatial, temporal and biological resolution and coverage. Extending the largely population-based vertical migration knowledge base to individual-based studies will be an important way forward. While tracking individual zooplankton in their natural habitats remains a major challenge, conducting trophic-scale, high-resolution, year-round studies that utilise emerging field sampling and observation techniques, molecular genetic tools and computational hardware and software will be the best solution to improve our understanding of zooplankton vertical migrations.
Collapse
Affiliation(s)
- Kanchana Bandara
- Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway.,Department of Arctic and Marine Biology, Faculty of Fisheries, Biosciences and Economics, UiT-The Arctic University of Norway, 9037, Tromsø, Norway
| | - Øystein Varpe
- Department of Biological Sciences, University of Bergen, 5020, Bergen, Norway.,Norwegian Institute for Nature Research, 5006, Bergen, Norway
| | - Lishani Wijewardene
- Department of Hydrology and Water Resources Management, Institute of Natural Resource Conservation, Kiel University, 24118, Kiel, Germany
| | - Vigdis Tverberg
- Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| | - Ketil Eiane
- Faculty of Biosciences and Aquaculture, Nord University, 8049, Bodø, Norway
| |
Collapse
|
9
|
Brewster LR, Cahill BV, Burton MN, Dougan C, Herr JS, Norton LI, McGuire SA, Pico M, Urban-Gedamke E, Bassos-Hull K, Tyminski JP, Hueter RE, Wetherbee BM, Shivji M, Burnie N, Ajemian MJ. First insights into the vertical habitat use of the whitespotted eagle ray Aetobatus narinari revealed by pop-up satellite archival tags. J Fish Biol 2021; 98:89-101. [PMID: 32985701 DOI: 10.1111/jfb.14560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
The whitespotted eagle ray Aetobatus narinari is a tropical to warm-temperate benthopelagic batoid that ranges widely throughout the western Atlantic Ocean. Despite conservation concerns for the species, its vertical habitat use and diving behaviour remain unknown. Patterns and drivers in the depth distribution of A. narinari were investigated at two separate locations, the western North Atlantic (Islands of Bermuda) and the eastern Gulf of Mexico (Sarasota, Florida, U.S.A.). Between 2010 and 2014, seven pop-up satellite archival tags were attached to A. narinari using three methods: a through-tail suture, an external tail-band and through-wing attachment. Retention time ranged from 0 to 180 days, with tags attached via the through-tail method retained longest. Tagged rays spent the majority of time (82.85 ± 12.17% S.D.) within the upper 10 m of the water column and, with one exception, no rays travelled deeper than ~26 m. One Bermuda ray recorded a maximum depth of 50.5 m, suggesting that these animals make excursions off the fore-reef slope of the Bermuda Platform. Individuals occupied deeper depths (7.42 ± 3.99 m S.D.) during the day versus night (4.90 ± 2.89 m S.D.), which may be explained by foraging and/or predator avoidance. Each individual experienced a significant difference in depth and temperature distributions over the diel cycle. There was evidence that mean hourly depth was best described by location and individual variation using a generalized additive mixed model approach. This is the first study to compare depth distributions of A. narinari from different locations and describe the thermal habitat for this species. Our study highlights the importance of region in describing A. narinari depth use, which may be relevant when developing management plans, whilst demonstrating that diel patterns appear to hold across individuals.
Collapse
Affiliation(s)
- Lauran R Brewster
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Brianna V Cahill
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Miranda N Burton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Cassady Dougan
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Jeffrey S Herr
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Laura Issac Norton
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Samantha A McGuire
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Marisa Pico
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Elizabeth Urban-Gedamke
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Kim Bassos-Hull
- Sharks and Rays Conservation Research Program, Mote Marine Laboratory, Sarasota, Florida, USA
| | - John P Tyminski
- Sharks and Rays Conservation Research Program, Mote Marine Laboratory, Sarasota, Florida, USA
| | - Robert E Hueter
- Sharks and Rays Conservation Research Program, Mote Marine Laboratory, Sarasota, Florida, USA
| | - Bradley M Wetherbee
- Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island, USA
- The Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, Florida, USA
| | - Mahmood Shivji
- The Guy Harvey Research Institute, Nova Southeastern University, Dania Beach, Florida, USA
| | | | - Matthew J Ajemian
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| |
Collapse
|
10
|
Kuzenkov O, Morozov A, Kuzenkova G. Exploring Evolutionary Fitness in Biological Systems Using Machine Learning Methods. Entropy (Basel) 2020; 23:E35. [PMID: 33383722 DOI: 10.3390/e23010035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/24/2020] [Accepted: 12/25/2020] [Indexed: 11/17/2022]
Abstract
Here, we propose a computational approach to explore evolutionary fitness in complex biological systems based on empirical data using artificial neural networks. The essence of our approach is the following. We first introduce a ranking order of inherited elements (behavioral strategies or/and life history traits) in considered self-reproducing systems: we use available empirical information on selective advantages of such elements. Next, we introduce evolutionary fitness, which is formally described as a certain function reflecting the introduced ranking order. Then, we approximate fitness in the space of key parameters using a Taylor expansion. To estimate the coefficients in the Taylor expansion, we utilize artificial neural networks: we construct a surface to separate the domains of superior and interior ranking of pair inherited elements in the space of parameters. Finally, we use the obtained approximation of the fitness surface to find the evolutionarily stable (optimal) strategy which maximizes fitness. As an ecologically important study case, we apply our approach to explore the evolutionarily stable diel vertical migration of zooplankton in marine and freshwater ecosystems. Using machine learning we reconstruct the fitness function of herbivorous zooplankton from empirical data and predict the daily trajectory of a dominant species in the northeastern Black Sea.
Collapse
|
11
|
MÖller KO, St. John M, Temming A, Diekmann R, Peters J, Floeter J, Sell AF, Herrmann JP, Gloe D, Schmidt JO, Hinrichsen HH, MÖllmann C. Predation risk triggers copepod small-scale behavior in the Baltic Sea. J Plankton Res 2020; 42:702-713. [PMID: 33239965 PMCID: PMC7677935 DOI: 10.1093/plankt/fbaa044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/01/2020] [Indexed: 06/11/2023]
Abstract
Predators not only have direct impact on biomass but also indirect, non-consumptive effects on the behavior their prey organisms. A characteristic response of zooplankton in aquatic ecosystems is predator avoidance by diel vertical migration (DVM), a behavior which is well studied on the population level. A wide range of behavioral diversity and plasticity has been observed both between- as well as within-species and, hence, investigating predator-prey interactions at the individual level seems therefore essential for a better understanding of zooplankton dynamics. Here we applied an underwater imaging instrument, the video plankton recorder (VPR), which allows the non-invasive investigation of individual, diel adaptive behavior of zooplankton in response to predators in the natural oceanic environment, providing a finely resolved and continuous documentation of the organisms' vertical distribution. Combing observations of copepod individuals observed with the VPR and hydroacoustic estimates of predatory fish biomass, we here show (i) a small-scale DVM of ovigerous Pseudocalanus acuspes females in response to its main predators, (ii) in-situ observations of a direct short-term reaction of the prey to the arrival of the predator and (iii) in-situ evidence of pronounced individual variation in this adaptive behavior with potentially strong effects on individual performance and ecosystem functioning.
Collapse
Affiliation(s)
| | - Michael St. John
- National Institute of Aquatic Resources, Technical University of Denmark, Kemitorvet, 2800 Kongens Lyngby, Copenhagen, Denmark
| | - Axel Temming
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Olbersweg 24, 22767 Hamburg, Germany
| | - Rabea Diekmann
- University of Applied Sciences Bremerhaven, An der Karlstadt 8, 27568 Bremerhaven, Germany
| | - Janna Peters
- Deutsches Zentrum für Marine Biodiversitätsforschung, Senckenberg am Meer, Südstrand 44, 26382 Wilhelmshaven, Germany
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Große Elbstrasse 133, 22767 Hamburg, Germany
| | - Jens Floeter
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Große Elbstrasse 133, 22767 Hamburg, Germany
| | - Anne F Sell
- Thünen Institute, Institute of Sea Fisheries, Herwigstraße 31, 27572 Bremerhaven, Germany
| | - Jens-Peter Herrmann
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Olbersweg 24, 22767 Hamburg, Germany
| | - Dominik Gloe
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Große Elbstrasse 133, 22767 Hamburg, Germany
| | - Jörn O Schmidt
- International Council for the Exploration of the Sea, Science Committee, H. C. Andersens Boulevard 44-46, 1553 Copenhagen V, Denmark
- Kiel University, Center for Ocean and Society, Neufeldtstrasse 10, 24118 Kiel, Germany
| | - Hans H Hinrichsen
- GEOMAR, Helmholtz Centre for Ocean Research, Marine Ecology, Marine Evolutionary Ecology, Düsternbrooker Weg 20, 24105 Kiel, Germany
| | - Christian MÖllmann
- Institute of Marine Ecosystem and Fishery Science, University of Hamburg, Große Elbstrasse 133, 22767 Hamburg, Germany
- Center for Earth System Research and Sustainability (CEN), University of Hamburg, Große Elbstraße 133, 22767 Hamburg, Germany
| |
Collapse
|
12
|
Stockwell JD, O’Malley BP, Hansson S, Chapina RJ, Rudstam LG, Weidel BC. Benthic habitat is an integral part of freshwater Mysis ecology. Freshw Biol 2020; 65:1997-2009. [PMID: 33288969 PMCID: PMC7689720 DOI: 10.1111/fwb.13594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 06/12/2023]
Abstract
Diel vertical migration (DVM) is common in aquatic organisms. The trade-off between reduced predation risk in deeper, darker waters during the day and increased foraging opportunities closer to the surface at night is a leading hypothesis for DVM behaviour.Diel vertical migration behaviour has dominated research and assessment frameworks for Mysis, an omnivorous mid-trophic level macroinvertebrate that exhibits strong DVM between benthic and pelagic habitats and plays key roles in many deep lake ecosystems. However, some historical literature and more recent evidence indicate that mysids also remain on the bottom at night, counter to expectations of DVM.We surveyed the freshwater Mysis literature using Web of Science (WoS; 1945-2019) to quantify the frequency of studies on demographics, diets, and feeding experiments that considered, assessed, or included Mysis that did not migrate vertically but remained in benthic habitats. We supplemented our WoS survey with literature searches for relevant papers published prior to 1945, journal articles and theses not listed in WoS, and additional references known to the authors but missing from WoS (e.g. only 47% of the papers used to evaluate in situ diets were identified by WoS).Results from the survey suggest that relatively little attention has been paid to the benthic components of Mysis ecology. Moreover, the literature suggests that reliance on Mysis sampling protocols using pelagic gear at night provides an incomplete picture of Mysis populations and their role in ecosystem structure and function.We summarise current knowledge of Mysis DVM and provide an expanded framework that more fully considers the role of benthic habitat. Acknowledging benthic habitat as an integral part of Mysis ecology will enable research to better understand the role of Mysis in food web processes.
Collapse
Affiliation(s)
- Jason D. Stockwell
- Rubenstein Ecosystem Science LaboratoryUniversity of VermontBurlingtonVTU.S.A.
| | | | - Sture Hansson
- Department of Ecology, Environment, and Plant SciencesStockholm UniversityStockholmSweden
| | - Rosaura J. Chapina
- Rubenstein Ecosystem Science LaboratoryUniversity of VermontBurlingtonVTU.S.A.
| | - Lars G. Rudstam
- Department of Natural ResourcesCornell UniversityIthacaNYU.S.A.
| | - Brian C. Weidel
- U.S. Geological SurveyGreat Lakes Science CenterOswegoNYU.S.A.
| |
Collapse
|
13
|
Haëntjens N, Della Penna A, Briggs N, Karp‐Boss L, Gaube P, Claustre H, Boss E. Detecting Mesopelagic Organisms Using Biogeochemical-Argo Floats. Geophys Res Lett 2020; 47:e2019GL086088. [PMID: 32713981 PMCID: PMC7375162 DOI: 10.1029/2019gl086088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/09/2020] [Accepted: 02/14/2020] [Indexed: 06/01/2023]
Abstract
During the North Atlantic Aerosols and Marine Ecosystems Study in the western North Atlantic, float-based profiles of fluorescent dissolved organic matter and backscattering exhibited distinct spike layers at ∼ 300 m. The locations of the spikes were at depths similar or shallower to where a ship-based scientific echo sounder identified layers of acoustic backscatter, an Underwater Vision Profiler detected elevated concentration of zooplankton, and mesopelagic fish were sampled by a mesopelagic net tow. The collocation of spike layers in bio-optical properties with mesopelagic organisms suggests that some can be detected with float-based bio-optical sensors. This opens the door to the investigation of such aggregations/layers in observations collected by the global biogeochemical-Argo array allowing the detection of mesopelagic organisms in remote locations of the open ocean under-sampled by traditional methods.
Collapse
Affiliation(s)
| | - Alice Della Penna
- Applied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539CNRS‐Ifremer‐IRD‐UBO‐Institut Universitaire Européen de la Mer (IUEM)PlouzanéFrance
| | | | - Lee Karp‐Boss
- School of Marine SciencesUniversity of MaineOronoMEUSA
| | - Peter Gaube
- Applied Physics LaboratoryUniversity of WashingtonSeattleWAUSA
| | - Hervé Claustre
- Laboratoire d'Océanographie de Villefranche, UMR 7093CNRS et Sorbonne UniversitéVillefranche‐sur‐merFrance
| | - Emmanuel Boss
- School of Marine SciencesUniversity of MaineOronoMEUSA
| |
Collapse
|
14
|
Tremblay N, Hünerlage K, Werner T. Hypoxia Tolerance of 10 Euphausiid Species in Relation to Vertical Temperature and Oxygen Gradients. Front Physiol 2020; 11:248. [PMID: 32265739 PMCID: PMC7107326 DOI: 10.3389/fphys.2020.00248] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 03/04/2020] [Indexed: 12/12/2022] Open
Abstract
Oxygen Minimum Zones prevail in most of the world's oceans and are particularly extensive in Eastern Boundary Upwelling Ecosystems such as the Humboldt and the Benguela upwelling systems. In these regions, euphausiids are an important trophic link between primary producers and higher trophic levels. The species are known as pronounced diel vertical migrators, thus facing different levels of oxygen and temperature within a 24 h cycle. Declining oxygen levels may lead to vertically constrained habitats in euphausiids, which consequently will affect several trophic levels in the food web of the respective ecosystem. By using the regulation index (RI), the present study aimed at investigating the hypoxia tolerances of different euphausiid species from Atlantic, Pacific as well as from Polar regions. RI was calculated from 141 data sets and used to differentiate between respiration strategies using median and quartile (Q) values: low degree of oxyregulation (0.25 < RI median < 0.5); high degree of oxyregulation (0.5 < RI median < 1; Q1 > 0.25 or Q3 > 0.75); and metabolic suppression (RI median, Q1 and Q3 < 0). RI values of the polar (Euphausia superba, Thysanoessa inermis) and sub-tropical (Euphausia hanseni, Nyctiphanes capensis, and Nematoscelis megalops) species indicate a high degree of oxyregulation, whereas almost perfect oxyconformity (RI median ≈ 0; Q1 < 0 and Q3 > 0) was identified for the neritic temperate species Thysanoessa spinifera and the tropical species Euphausia lamelligera. RI values of Euphausia distinguenda and the Humboldt species Euphausia mucronata qualified these as metabolic suppressors. RI showed a significant impact of temperature on the respiration strategy of E. hanseni from oxyregulation to metabolic suppression. The species' estimated hypoxia tolerances and the degree of oxyconformity vs. oxyregulation were linked to diel vertical migration behavior and the temperature experienced during migration. The results highlight that the euphausiid species investigated have evolved various strategies to deal with different levels of oxygen, ranging from species showing a high degree of oxyconformity to strong oxyregulation. Neritic species may be more affected by hypoxia, as these are often short-distance-migrators and only adapted to a narrow range of environmental conditions.
Collapse
Affiliation(s)
- Nelly Tremblay
- Shelf Sea System Ecology, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Helgoland, Germany
| | - Kim Hünerlage
- Institute for Sea Fisheries, Thünen Institute, Bremerhaven, Germany
| | | |
Collapse
|
15
|
Abstract
The water flea Daphnia moves to deeper waters to avoid predators when it detects a chemical produced by fish.
Collapse
Affiliation(s)
- Georg Pohnert
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Jena, Germany.,Max Planck Institute for Chemical Ecology, Jena, Germany
| |
Collapse
|
16
|
Hahn MA, Effertz C, Bigler L, von Elert E. 5α-cyprinol sulfate, a bile salt from fish, induces diel vertical migration in Daphnia. eLife 2019; 8:44791. [PMID: 31045492 PMCID: PMC6559785 DOI: 10.7554/elife.44791] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 05/02/2019] [Indexed: 01/17/2023] Open
Abstract
Prey are under selection to minimize predation losses. In aquatic environments, many prey use chemical cues released by predators, which initiate predator avoidance. A prominent example of behavioral predator-avoidance constitutes diel vertical migration (DVM) in the freshwater microcrustacean Daphnia spp., which is induced by chemical cues (kairomones) released by planktivorous fish. In a bioassay-guided approach using liquid chromatography and mass spectrometry, we identified the kairomone from fish incubation water as 5α-cyprinol sulfate inducing DVM in Daphnia at picomolar concentrations. The role of 5α-cyprinol sulfate in lipid digestion in fish explains why from an evolutionary perspective fish has not stopped releasing 5α-cyprinol sulfate despite the disadvantages for the releaser. The identification of the DVM-inducing kairomone enables investigating its spatial and temporal distribution and the underlying molecular mechanism of its perception. Furthermore, it allows to test if fish-mediated inducible defenses in other aquatic invertebrates are triggered by the same compound.
Collapse
Affiliation(s)
- Meike Anika Hahn
- Aquatic Chemical Ecology, Department of Biology, University of Koeln, Koeln, Germany
| | - Christoph Effertz
- Aquatic Chemical Ecology, Department of Biology, University of Koeln, Koeln, Germany
| | - Laurent Bigler
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Eric von Elert
- Aquatic Chemical Ecology, Department of Biology, University of Koeln, Koeln, Germany
| |
Collapse
|
17
|
Bozman A, Titelman J, Kaartvedt S, Eiane K, Aksnes DL. Jellyfish distribute vertically according to irradiance. J Plankton Res 2017; 39:280-289. [PMID: 29731527 PMCID: PMC5914403 DOI: 10.1093/plankt/fbw097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 12/07/2016] [Accepted: 12/19/2016] [Indexed: 06/08/2023]
Abstract
We tested the hypothesis that the coronate jellyfish Periphylla periphylla distributes vertically according to a preferential range of absolute light intensities. The study was carried out in Lurefjorden, Norway, a fjord characterized by mass occurrences of this jellyfish. We collected data on the vertical distribution of P. periphylla medusa during day, dusk and night periods from video observations by a remotely operated vehicle in relation to estimated ambient light levels. Our results suggest that large P. periphylla (average size in catches ~9 cm diameter) avoided total irradiance levels above 5×10-3 µmol quanta m-2 s-1. Nearly two-thirds of the population stayed above irradiance of 10-7 µmol quanta m-2 s-1 during daytime, while some individuals occupied much darker water. Thus, part of the population appeared to distribute vertically and undertake diel vertical migration (DVM) according to a preferential range of light intensities.
Collapse
Affiliation(s)
- Andrea Bozman
- Faculty of Biosciences and Aquaculture, Nord University, Po Box 1490, 8049 Bodø, Norway
| | - Josefin Titelman
- Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
| | - Stein Kaartvedt
- Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
| | - Ketil Eiane
- Faculty of Biosciences and Aquaculture, Nord University, Po Box 1490, 8049 Bodø, Norway
| | - Dag L. Aksnes
- Department of Biology, University of Bergen, Thormøhlensgt 53 A/B, 5020 Bergen, Norway
| |
Collapse
|
18
|
Freitas C, Olsen EM, Moland E, Ciannelli L, Knutsen H. Behavioral responses of Atlantic cod to sea temperature changes. Ecol Evol 2015; 5:2070-83. [PMID: 26045957 PMCID: PMC4449760 DOI: 10.1002/ece3.1496] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 03/04/2015] [Accepted: 03/10/2015] [Indexed: 11/07/2022] Open
Abstract
Understanding responses of marine species to temperature variability is essential to predict impacts of future climate change in the oceans. Most ectotherms are expected to adjust their behavior to avoid extreme temperatures and minimize acute changes in body temperature. However, measuring such behavioral plasticity in the wild is challenging. Combining 4 years of telemetry-derived behavioral data on juvenile and adult (30–80 cm) Atlantic cod (Gadus morhua), and in situ ocean temperature measurements, we found a significant effect of sea temperature on cod depth use and activity level in coastal Skagerrak. During summer, cod were found in deeper waters when sea surface temperature increased. Further, this effect of temperature was stronger on larger cod. Diel vertical migration, which consists in a nighttime rise to shallow feeding habitats, was stronger among smaller cod. As surface temperature increased beyond ∼15°C, their vertical migration was limited to deeper waters. In addition to larger diel vertical migrations, smaller cod were more active and travelled larger distances compared to larger specimens. Cold temperatures during winter tended, however, to reduce the magnitude of diel vertical migrations, as well as the activity level and distance moved by those smaller individuals. Our findings suggest that future and ongoing rises in sea surface temperature may increasingly deprive cod in this region from shallow feeding areas during summer, which may be detrimental for local populations of the species.
Collapse
Affiliation(s)
- Carla Freitas
- Department of Natural Sciences, Faculty of Engineering and Science, University of Agder Post Box 422, 4604, Kristiansand, Norway ; Institute of Marine Research Flødevigen, 4817, His, Norway ; Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto 4050-123, Porto, Portugal
| | - Esben Moland Olsen
- Department of Natural Sciences, Faculty of Engineering and Science, University of Agder Post Box 422, 4604, Kristiansand, Norway ; Institute of Marine Research Flødevigen, 4817, His, Norway ; Department of Biosciences, Centre for Ecological and Evolutionary Syntheses (CEES), University of Oslo PO Box 1066, Blindern, 0316, Oslo, Norway
| | - Even Moland
- Department of Natural Sciences, Faculty of Engineering and Science, University of Agder Post Box 422, 4604, Kristiansand, Norway ; Institute of Marine Research Flødevigen, 4817, His, Norway
| | - Lorenzo Ciannelli
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University 104 CEOAS Administration Building, Corvallis, Oregon, 97331-5503
| | - Halvor Knutsen
- Department of Natural Sciences, Faculty of Engineering and Science, University of Agder Post Box 422, 4604, Kristiansand, Norway ; Institute of Marine Research Flødevigen, 4817, His, Norway ; Department of Biosciences, Centre for Ecological and Evolutionary Syntheses (CEES), University of Oslo PO Box 1066, Blindern, 0316, Oslo, Norway
| |
Collapse
|
19
|
Abstract
Measurements show that anaerobic ammonium oxidation with nitrite (anammox) is a major pathway of fixed nitrogen removal in the anoxic zones of the open ocean. Anammox requires a source of ammonium, which under anoxic conditions could be supplied by the breakdown of sinking organic matter via heterotrophic denitrification. However, at many locations where anammox is measured, denitrification rates are small or undetectable. Alternative sources of ammonium have been proposed to explain this paradox, for example through dissimilatory reduction of nitrate to ammonium and transport from anoxic sediments. However, the relevance of these sources in open-ocean anoxic zones is debated. Here, we bring to attention an additional source of ammonium, namely, the daytime excretion by zooplankton and micronekton migrating from the surface to anoxic waters. We use a synthesis of acoustic data to show that, where anoxic waters occur within the water column, most migrators spend the daytime within them. Although migrators export only a small fraction of primary production from the surface, they focus excretion within a confined depth range of anoxic water where particle input is small. Using a simple biogeochemical model, we suggest that, at those depths, the source of ammonium from organisms undergoing diel vertical migrations could exceed the release from particle remineralization, enhancing in situ anammox rates. The contribution of this previously overlooked process, and the numerous uncertainties surrounding it, call for further efforts to evaluate the role of animals in oxygen minimum zone biogeochemistry.
Collapse
|
20
|
Berge J, Cottier F, Varpe Ø, Renaud PE, Falk-Petersen S, Kwasniewski S, Griffiths C, Søreide JE, Johnsen G, Aubert A, Bjærke O, Hovinen J, Jung-Madsen S, Tveit M, Majaneva S. Arctic complexity: a case study on diel vertical migration of zooplankton. J Plankton Res 2014; 36:1279-1297. [PMID: 25221372 PMCID: PMC4161229 DOI: 10.1093/plankt/fbu059] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 06/16/2014] [Indexed: 06/01/2023]
Abstract
Diel vertical migration (DVM) of zooplankton is a global phenomenon, characteristic of both marine and limnic environments. At high latitudes, patterns of DVM have been documented, but rather little knowledge exists regarding which species perform this ecologically important behaviour. Also, in the Arctic, the vertically migrating components of the zooplankton community are usually regarded as a single sound scattering layer (SSL) performing synchronized patterns of migration directly controlled by ambient light. Here, we present evidence for hitherto unknown complexity of Arctic marine systems, where zooplankton form multiple aggregations through the water column seen via acoustics as distinct SSLs. We show that while the initiation of DVM during the autumnal equinox is light mediated, the vertical positioning of the migrants during day is linked more to the thermal characteristics of water masses than to irradiance. During night, phytoplankton biomass is shown to be the most important factor determining the vertical positioning of all migrating taxa. Further, we develop a novel way of representing acoustic data in the form of a Sound Image (SI) that enables a direct comparison of the relative importance of each potential scatterer based upon the theoretical contribution of their backscatter. Based on our comparison of locations with contrasting hydrography, we conclude that a continued warming of the Arctic is likely to result in more complex ecotones across the Arctic marine system.
Collapse
Affiliation(s)
- Jørgen Berge
- Faculty of Biosciences, Fisheries and Economics, University of Tromsø, 9037 Tromsø, Norway
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
| | - Finlo Cottier
- Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll PA37 1QA, UK
| | - Øystein Varpe
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
- Akvaplan-Niva, Fram Centre for Climate and the Environment, N-9296 Tromsø, Norway
| | - Paul E. Renaud
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
- Akvaplan-Niva, Fram Centre for Climate and the Environment, N-9296 Tromsø, Norway
| | - Stig Falk-Petersen
- Faculty of Biosciences, Fisheries and Economics, University of Tromsø, 9037 Tromsø, Norway
- Akvaplan-Niva, Fram Centre for Climate and the Environment, N-9296 Tromsø, Norway
| | - Sawomir Kwasniewski
- Institute of Oceanology Polish Academy of Sciences, Powstancow Warszawy 55, 81-712 Sopot, Poland
| | - Colin Griffiths
- Scottish Association for Marine Science, Scottish Marine Institute, Oban, Argyll PA37 1QA, UK
| | | | - Geir Johnsen
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
- Department of Biology, Trondhjem Biological Station, Applied Underwater Robotics Laboratory, Norwegian University of Science & Technology (NTNU), N-7491 Trondheim, Norway
| | - Anais Aubert
- Faculty of Biosciences, Fisheries and Economics, University of Tromsø, 9037 Tromsø, Norway
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
| | - Oda Bjærke
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
| | - Johanna Hovinen
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
- Norwegian Polar Institute, Fram Centre for Climate and the Environment, N-9296 Tromsø, Norway
| | | | - Martha Tveit
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
| | - Sanna Majaneva
- The University Centre in Svalbard, N-9171 Longyearbyen, Norway
- Faculty of Biological and Environmental Sciences, University of Helsinki, FI-00014 Helsinki, Finland
| |
Collapse
|
21
|
Abstract
A huge variety of organisms respond to the presence of predators with inducible defences, each of which is associated with costs. Many genotypes have the potential to respond with more than one defence, and it has been argued that it would be maladaptive to exhibit all possible responses at the same time. Here, we test how a well-known anti-fish defence in Daphnia, life-history changes (LHC), is controlled by light. We show that the kairomone-mediated reduction in size at first reproduction is inversely coupled to the light intensity. A similar effect was found for the kairomone-mediated expression of candidate genes in Daphnia. We argue that the light intensity an individual is exposed to determines the degree of LHC, which allows for plastic adjustment to fluctuating environments and simultaneously minimizes the associated costs of multiple alternately deployable defences. It is hypothesized that this allows for a coupling of multiple defences, i.e. LHC and diel vertical migration.
Collapse
Affiliation(s)
- Christoph Effertz
- Zoological Institute, Aquatic Chemical Ecology, University of Cologne, , Zülpicher Strasse 47b, Cologne 50674, Germany
| | | |
Collapse
|
22
|
Lewis CN, Brown KA, Edwards LA, Cooper G, Findlay HS. Sensitivity to ocean acidification parallels natural pCO2 gradients experienced by Arctic copepods under winter sea ice. Proc Natl Acad Sci U S A 2013; 110:E4960-7. [PMID: 24297880 DOI: 10.1073/pnas.1315162110] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Arctic Ocean already experiences areas of low pH and high CO2, and it is expected to be most rapidly affected by future ocean acidification (OA). Copepods comprise the dominant Arctic zooplankton; hence, their responses to OA have important implications for Arctic ecosystems, yet there is little data on their current under-ice winter ecology on which to base future monitoring or make predictions about climate-induced change. Here, we report results from Arctic under-ice investigations of copepod natural distributions associated with late-winter carbonate chemistry environmental data and their response to manipulated pCO2 conditions (OA exposures). Our data reveal that species and life stage sensitivities to manipulated OA conditions were correlated with their vertical migration behavior and with their natural exposures to different pCO2 ranges. Vertically migrating adult Calanus spp. crossed a pCO2 range of >140 μatm daily and showed only minor responses to manipulated high CO2. Oithona similis, which remained in the surface waters and experienced a pCO2 range of <75 μatm, showed significantly reduced adult and nauplii survival in high CO2 experiments. These results support the relatively untested hypothesis that the natural range of pCO2 experienced by an organism determines its sensitivity to future OA and highlight that the globally important copepod species, Oithona spp., may be more sensitive to future high pCO2 conditions compared with the more widely studied larger copepods.
Collapse
|
23
|
Dupont N, Aksnes DL. Simulation of optically conditioned retention and mass occurrences of Periphylla periphylla. J Plankton Res 2010; 32:773-783. [PMID: 20454515 PMCID: PMC2864668 DOI: 10.1093/plankt/fbq015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 12/18/2009] [Indexed: 05/16/2023]
Abstract
Jellyfish blooms are of increasing concern in many parts of the world, and in Norwegian fjords an apparent increase in mass occurrences of the deep water jellyfish Periphylla periphylla has attracted attention. Here we investigate the hypothesis that changes in the water column light attenuation might cause local retention and thereby facilitate mass occurrences. We use a previously tested individual-based model of light-mediated vertical migration in P. periphylla to simulate how retention is affected by changes in light attenuation. Our results suggest that light attenuation, in combination with advection, has a two-sided effect on retention and that three fjord categories can be defined. In category 1, increased light attenuation turns fjords into dark "deep-sea" environments which increase the habitat and retention of P. periphylla. In category 2, an optimal light attenuation facilitates the maximum retention and likelihood for mass occurrences. In category 3, further increase in light attenuation, however, shoals the habitat so that individuals are increasingly exposed to advection and this results in loss of individuals and decreased retention. This classification requires accurate determinations of the organism's light preference, the water column light attenuation and topographical characteristics affecting advection.
Collapse
|