1
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Cohen KE, Lucanus O, Summers AP, Kolmann MA. Lip service: Histological phenotypes correlate with diet and feeding ecology in herbivorous pacus. Anat Rec (Hoboken) 2023; 306:326-342. [PMID: 36128598 DOI: 10.1002/ar.25075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 07/14/2022] [Accepted: 08/24/2022] [Indexed: 01/27/2023]
Abstract
Complex prey processing requires the repositioning of food between the teeth, as modulated by a soft tissue appendage like a tongue or lips. In this study, we trace the evolution of lips and ligaments, which are used during prey capture and prey processing in an herbivorous group of fishes. Pacus (Serrasalmidae) are Neotropical freshwater fishes that feed on leaves, fruits, and seeds. These prey are hard or tough, require high forces to fracture, contain abrasive or caustic elements, or deform considerably before failure. Pacus are gape-limited and do not have the pharyngeal jaws many bony fishes use to dismantle and/or transport prey. Despite their gape limitation, pacus feed on prey larger than their mouths, relying on robust teeth and a hypertrophied lower lip for manipulation and breakdown of food. We used histology to compare the lip morphology across 14 species of pacus and piranhas to better understand this soft tissue. We found that frugivorous pacus have larger, more complex lips which are innervated and folded at their surface, while grazing species have callused, mucus-covered lips. Unlike mammalian lips or tongues, pacu lips lack any intrinsic skeletal or smooth muscle. This implies that pacu lips lack dexterity; however, we found a novel connection to the primordial ligament which suggests that the lips are actuated by the jaw adductors. We propose that pacus combine hydraulic repositioning of prey inside the buccal cavity with direct oral manipulation, the latter using a combination of a morphologically heterodont dentition and compliant lips for reorienting food.
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Affiliation(s)
- Karly E Cohen
- Biology Department, University of Washington, Seattle, Washington, USA.,Friday Harbor Laboratories, University of Washington, Friday Harbor, USA
| | - Oliver Lucanus
- BelowWater, Inc., Montreal, Quebec, Canada.,Applied Remote Sensing Lab, Department of Geography, McGill University, Montreal, Quebec, Canada
| | - Adam P Summers
- Biology Department, University of Washington, Seattle, Washington, USA.,Friday Harbor Laboratories, University of Washington, Friday Harbor, USA
| | - Matthew A Kolmann
- Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, USA.,Dept. of Biology, University of Louisville, Louisville, Kentucky, USA
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2
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Palecek AM, Schoenfuss HL, Blob RW. Sucker Shapes, Skeletons and Bioinspiration: How Hard and Soft Tissue Morphology Generates Adhesive Performance in Waterfall Climbing Goby Fishes. Integr Comp Biol 2022; 62:934-944. [PMID: 35767861 DOI: 10.1093/icb/icac094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 06/12/2022] [Accepted: 06/27/2022] [Indexed: 11/14/2022] Open
Abstract
Many teleost fishes, such as gobies, have fused their paired pelvic fins into an adhesive disc. Gobies can use their pelvic suckers to generate passive adhesive forces (as in engineered suction cups) and different species exhibit a range of adhesive performance, with some even able to climb waterfalls. Previous studies have documented that, in the Hawaiian Islands, species capable of climbing higher waterfalls produce the highest passive pull-off forces, and species found at higher elevation sites are likely to have more rounded suction discs than those found in the lowest stream segments. Morphology of the pelvic girdle also varies between species, with more robust skeletons in taxa with superior passive adhesion. To investigate what factors impact the passive adhesive performance of waterfall climbing gobies, we tested biomimetic suction cups designed with a range of shapes and embedded bioinspired "skeletons" based on micro-CT scans of goby pelvic girdles. We found that while the presence of an internal skeleton may provide some support against failure, the performance of suction cups may be more strongly affected by their external shape. Nonetheless, factors besides external shape and skeletal morphology may still have a stronger influence on sucker tenacity. Our results suggest that the relationship between suction disc morphology and adhesive performance may be influenced by a variety of physical factors, and live animal performance likely is further complicated by muscle activation and climbing behavior. These results have implications for the evolution of suction disc shape in adhesive fishes and for improving the design of biomimetic suction cups.
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Affiliation(s)
- A M Palecek
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - H L Schoenfuss
- Aquatic Toxicology Laboratory, Saint Cloud State University, Saint Cloud, MN 56301, USA
| | - R W Blob
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
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3
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Williams KL, Evans KM, Simons AM. Tooth replacement and attachment morphology in the Pacific Leaping Blenny, Alticus arnoldorum (Blenniiformes: Blenniidae: Salariini) with a discussion on tooth function. Anat Rec (Hoboken) 2021; 305:1787-1803. [PMID: 34708582 DOI: 10.1002/ar.24819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/08/2021] [Accepted: 09/28/2021] [Indexed: 11/06/2022]
Abstract
Modes of teleost tooth replacement and attachment have historically been described using discrete classification systems that categorize major patterns across taxa. While useful, these discrete classification schemes understate teleost tooth diversity. The "unattached" dentition of salariin combtooth blennies (Blenniiformes: Blenniidae: Salariini) is frequently overlooked due to its perceived complexity, so we examined the Pacific Leaping Blenny, Alticus arnoldorum, to describe this complex morphology. Using a range of methods including histology, SEM, microCT scanning, and clearing and staining, we establish a descriptive model of tooth replacement for A. arnoldorum. We then use our descriptive model of tooth replacement to propose a hypothesis of tooth function in salariin blennies. Our results show that A. arnoldorum exhibits grouped, extraosseous replacement of feeding teeth upon a discontinuous, permanent dental lamina. We also find that tooth replacement occurs within lip tissue that is laterally displaced from the distal margins of the jaw bones, a process previously undocumented in teleost fish. Feeding teeth attach to the dentigerous bone via a primary attachment mode consisting of a continuous collagen band at the posterior base of the teeth, and a secondary attachment mode consisting of epithelial cells. Alticus arnoldorum presents novel modes of tooth replacement and attachment that challenge historical classification modes of teleost dentition. Our descriptive tooth replacement model also provides a reliable framework to propose hypotheses of tooth function that can be applied in future comparative studies on salariin blennies and other long-toothed teleosts to further elucidate the functional role of long-toothed fishes in aquatic ecosystems.
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Affiliation(s)
- Keiffer L Williams
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, USA
| | - Kory M Evans
- Department of BioSciences, Rice University, Houston, Texas, USA
| | - Andrew M Simons
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, Saint Paul, Minnesota, USA.,Bell Museum of Natural History, University of Minnesota, Saint Paul, Minnesota, USA
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4
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Forker GK, Schoenfuss HL, Blob RW, Diamond KM. Bendy to the bone: Links between vertebral morphology and waterfall climbing in amphidromous gobioid fishes. J Anat 2021; 239:747-754. [PMID: 33928628 PMCID: PMC8349408 DOI: 10.1111/joa.13449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 11/28/2022] Open
Abstract
Locomotor force production imposes strong demands on organismal form. Thus, the evolution of novel locomotor modes is often associated with morphological adaptations that help to meet those demands. In the goby lineage of fishes, most species are marine and use their fused pelvic fins to facilitate station holding in wave-swept environments. However, several groups of gobies have evolved an amphidromous lifecycle, in which larvae develop in the ocean but juveniles migrate to freshwater for their adult phase. In many of these species, the pelvic fins have been co-opted to aid in climbing waterfalls during upstream migrations to adult habitats. During horizontal swimming, forces are produced by axial musculature pulling on the vertebral column. However, during vertical climbing, gravity also exerts forces along the length of the vertebral column. In this study, we searched for novel aspects of vertebral column form that might be associated with the distinctive locomotor strategies of climbing gobies. We predicted that stiffness would vary along the length of the vertebral column due to competing demands for stability of the suction disk anteriorly and flexibility for axial thrust production posteriorly. We also predicted that derived, climbing goby species would require stiffer backbones to aid in vertical thrust production compared to non-climbing species. To test these predictions, we used microcomputed tomography scans to compare vertebral anatomy (centrum length, centrum width, and intervertebral space) along the vertebral column for five gobioid species that differ in climbing ability. Our results support our second prediction, that gobies are more flexible in the posterior portion of the body. However, the main variation in vertebral column form associated with climbing ability was the presence of larger intervertebral spaces in Sicyopterus stimpsoni, a species that uses a distinctive inching behavior to climb. These results build on past kinematic studies of goby climbing performance and lend insights into how the underlying vertebral structure of these fishes may enable their novel locomotion.
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Affiliation(s)
- Grace K. Forker
- Department of Biological SciencesClemson UniversityClemsonSCUSA
- School of Veterinary MedicineUniversity of GeorgiaAthensGAUSA
| | | | - Richard W. Blob
- Department of Biological SciencesClemson UniversityClemsonSCUSA
| | - Kelly M. Diamond
- Department of Biological SciencesClemson UniversityClemsonSCUSA
- Center for Developmental Biology and Regenerative MedicineSeattle Children’s Research InstituteSeattleWAUSA
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5
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Diamond KM, Lagarde R, Griner JG, Ponton D, Powder KE, Schoenfuss HL, Walker JA, Blob RW. Interactions among multiple selective pressures on the form–function relationship in insular stream fishes. Biol J Linn Soc Lond 2021. [DOI: 10.1093/biolinnean/blab098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Relationships between body shape and escape performance are well established for many species. However, organisms can face multiple selection pressures that might impose competing demands. Many fishes use fast starts for escaping predator attacks, whereas some species of gobiid fishes have evolved the ability to climb waterfalls out of predator-dense habitats. The ancestral ‘powerburst’ climbing mechanism uses lateral body undulations to move up waterfalls, whereas a derived ‘inching’ mechanism uses rectilinear locomotion. We examined whether fast-start performance is impacted by selection imposed from the new functional demands of climbing. We predicted that non-climbing species would show morphology and fast-start performance that facilitate predator evasion, because these fish live consistently with predators and are not constrained by the demands of climbing. We also predicted that, by using lateral undulations, powerburst climbers would show escape performance superior to that of inchers. We compared fast starts and body shape across six goby species. As predicted, non-climbing fish exhibited distinct morphology and responded more frequently to an attack stimulus than climbing species. Contrary to our predictions, we found no differences in escape performance among climbing styles. These results indicate that selection for a competing pressure need not limit the ability of prey to escape predator attacks.
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Affiliation(s)
- Kelly M Diamond
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA
| | - Raphaël Lagarde
- Hydrô Réunion, Z.I. Les Sables, Etang Salé, La Réunion, France
- Université de Perpignan Via Domitia – CNRS, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR, Perpignan, France
| | - J Gill Griner
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Dominique Ponton
- ENTROPIE, IRD-Université de La Réunion-CNRS-Université de la Nouvelle-Calédonie-IFREMER, c/o Institut Halieutique et des Sciences Marines (IH.SM), Université de Toliara, Rue Dr. Rabesandratana, BP, Toliara, Madagascar
| | - Kara E Powder
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
| | - Heiko L Schoenfuss
- Aquatic Toxicology Laboratory, Saint Cloud State University, Saint Cloud, MN, USA
| | - Jeffrey A Walker
- Department of Biological Sciences, University of Southern Maine, Portland, ME, USA
| | - Richard W Blob
- Department of Biological Sciences, Clemson University, Clemson, SC, USA
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6
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Gorman CE, Hulsey CD. Non-trophic Functional Ecology of Vertebrate Teeth: A Review. Integr Comp Biol 2021; 60:665-675. [PMID: 32573716 DOI: 10.1093/icb/icaa086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Teeth are critical to the functional ecology of vertebrate trophic abilities, but are also used for a diversity of other non-trophic tasks. Teeth can play a substantial role in how animals move, manipulate their environment, positively interact with conspecifics, antagonistically interact with other organisms, and sense the environment. We review these non-trophic functions in an attempt to place the utility of human and all other vertebrate dentitions in a more diverse framework that emphasizes an expanded view of the functional importance and ecological diversity of teeth. In light of the extensive understanding of the developmental genetics, trophic functions, and evolutionary history of teeth, comparative studies of vertebrate dentitions will continue to provide unique insights into multi-functionality, many-to-one mapping, and the evolution of novel abilities.
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Affiliation(s)
- Courtney E Gorman
- Department of Biology, University of Konstanz, Konstanz 78457, Germany
| | - C Darrin Hulsey
- Department of Biology, University of Konstanz, Konstanz 78457, Germany
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7
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Blob RW, Baumann T, Diamond KM, Young VKH, Schoenfuss HL. Functional correlations of axial muscle fiber type proportions in the waterfall-climbing Hawaiian stream fish Sicyopterus stimpsoni. J Anat 2020; 236:1160-1166. [PMID: 32092791 PMCID: PMC7219618 DOI: 10.1111/joa.13169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/20/2020] [Accepted: 01/23/2020] [Indexed: 11/27/2022] Open
Abstract
Assessing the factors that contribute to successful locomotor performance can provide critical insight into how animals survive in challenging habitats. Locomotion is powered by muscles, so that differences in the relative proportions of red (slow-oxidative) vs. white (fast-glycolytic) fibers can have significant implications for locomotor performance. We compared the relative proportions of axial red muscle fibers between groups of juveniles of the amphidromous gobiid fish, Sicyopterus stimpsoni, from the Hawaiian Islands. Juveniles of this species migrate from the ocean into freshwater streams, navigating through a gauntlet of predators that require rapid escape responses, before reaching waterfalls which must be climbed (using a slow, inching behavior) to reach adult breeding habitats. We found that fish from Kaua'i have a smaller proportion of red fibers in their tail muscles than fish from Hawai'i, matching expectations based on the longer pre-waterfall stream reaches of Kaua'i that could increase exposure to predators, making reduction of red muscle and increases in white muscle advantageous. However, no difference in red muscle proportions was identified between fish that were either successful or unsuccessful in scaling model waterfalls during laboratory climbing trials, suggesting that proportions of red muscle are near a localized fitness peak among Hawaiian individuals.
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Affiliation(s)
- Richard W. Blob
- Department of Biological SciencesClemson UniversityClemsonSCUSA
| | - Travis Baumann
- Aquatic Toxicology LaboratorySt. Cloud State UniversitySt. CloudMNUSA
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8
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St John ME, Holzman R, Martin CH. Rapid adaptive evolution of scale-eating kinematics to a novel ecological niche. J Exp Biol 2020; 223:jeb217570. [PMID: 32029459 PMCID: PMC7097200 DOI: 10.1242/jeb.217570] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/29/2020] [Indexed: 01/08/2023]
Abstract
The origins of novel trophic specialization, in which organisms begin to exploit resources for the first time, may be explained by shifts in behavior such as foraging preferences or feeding kinematics. One way to investigate behavioral mechanisms underlying ecological novelty is by comparing prey capture kinematics among species. We investigated the contribution of kinematics to the origins of a novel ecological niche for scale-eating within a microendemic adaptive radiation of pupfishes on San Salvador Island, Bahamas. We compared prey capture kinematics across three species of pupfish while they consumed shrimp and scales in the lab, and found that scale-eating pupfish exhibited peak gape sizes twice as large as in other species, but also attacked prey with a more obtuse angle between their lower jaw and suspensorium. We then investigated how this variation in feeding kinematics could explain scale-biting performance by measuring bite size (surface area removed) from standardized gelatin cubes. We found that a combination of larger peak gape and more obtuse lower jaw and suspensorium angles resulted in approximately 40% more surface area removed per strike, indicating that scale-eaters may reside on a performance optimum for scale biting. To test whether feeding performance could contribute to reproductive isolation between species, we also measured F1 hybrids and found that their kinematics and performance more closely resembled generalists, suggesting that F1 hybrids may have low fitness in the scale-eating niche. Ultimately, our results suggest that the evolution of strike kinematics in this radiation is an adaptation to the novel niche of scale eating.
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Affiliation(s)
- Michelle E St John
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Roi Holzman
- School of Zoology, Tel Aviv University, Eilat 6997801, Israel
- Inter-University Institute for Marine Sciences, Eilat 8810302, Israel
| | - Christopher H Martin
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720, USA
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9
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Blob RW, Lagarde R, Diamond KM, Keeffe RM, Bertram RS, Ponton D, Schoenfuss HL. Functional Diversity of Evolutionary Novelties: Insights from Waterfall-Climbing Kinematics and Performance of Juvenile Gobiid Fishes. Integr Org Biol 2019; 1:obz029. [PMID: 33791543 PMCID: PMC7671142 DOI: 10.1093/iob/obz029] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The evolution of novel functional traits can contribute substantially to the diversification of lineages. Older functional traits might show greater variation than more recently evolved novelties, due to the accrual of evolutionary changes through time. However, functional complexity and many-to-one mapping of structure to function could complicate such expectations. In this context, we compared kinematics and performance across juveniles from multiple species for two styles of waterfall-climbing that are novel to gobiid fishes: ancestral “powerburst” climbing, and more recently evolved “inching”, which has been confirmed only among species of a single genus that is nested within the clade of powerburst climbers. Similar net climbing speeds across inching species seem, at first, to indicate that this more recently evolved mode of climbing exhibits less functional diversity. However, these similar net speeds arise through different pathways: Sicyopterus stimpsoni from Hawai’i move more slowly than S. lagocephalus from La Réunion, but may also spend more time moving. The production of similar performance between multiple functional pathways reflects a situation that resembles the phenomenon of many-to-one mapping of structure to function. Such similarity has the potential to mask appropriate interpretations of relative functional diversity between lineages, unless the mechanisms underlying performance are explored. More specifically, similarity in net performance between “powerburst” and “inching” styles indicates that selection on climbing performance was likely a limited factor in promoting the evolution of inching as a new mode of climbing. In this context, other processes (e.g., exaptation) might be implicated in the origin of this functional novelty.
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Affiliation(s)
- R W Blob
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - R Lagarde
- Hydrô Réunion, Z.I. Les Sables, 97427 Etang Salé, La Réunion, France.,Université de Perpignan Via Domitia - CNRS, Centre de Formation et de Recherche sur les Environnements Méditerranéens, UMR 5110, F 66860 Perpignan, France
| | - K M Diamond
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - R M Keeffe
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - R S Bertram
- Aquatic Toxicology Laboratory, St. Cloud State University, St. Cloud, MN 29634, USA
| | - D Ponton
- ENTROPIE, IRD, Université de La Réunion, CNRS, Laboratoire d'Excellence CORAIL, c/o Institut Halieutique et des Sciences Marines (IH.SM), Université de Toliara, Route du port, Toliara, P 141, 601 B, Madagascar
| | - H L Schoenfuss
- Aquatic Toxicology Laboratory, St. Cloud State University, St. Cloud, MN 29634, USA
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10
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Lord C, Bellec L, Dettaï A, Bonillo C, Keith P. Does your lip stick? Evolutionary aspects of the mouth morphology of the Indo‐Pacific clinging goby of the Sicyopterusgenus (Teleostei: Gobioidei: Sicydiinae) based on mitogenome phylogeny. J ZOOL SYST EVOL RES 2019. [DOI: 10.1111/jzs.12291] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Clara Lord
- Unité Biologie des organismes et écosystèmes aquatiques (BOREA), Sorbonne Université, Muséum national d’Histoire naturelle, Université de Caen Normandie, CNRS, IRD, CP26 Université des Antilles Paris France
| | - Laure Bellec
- IFREMER, Centre Brest, REM/EEP/LEP ZI de la Pointe du Diable Plouzané France
| | - Agnès Dettaï
- Institut Systématique, Évolution, Biodiversité (ISYEB), Muséum national d’Histoire naturelle, École Pratique des Hautes Études, CNRS, CP30 Sorbonne Université Paris France
| | - Céline Bonillo
- Département Systématique et Évolution, UMS 2700 “Outils et Méthodes de la Systématique Intégrative” MNHN‐CNRS, Service de Systématique Moléculaire Muséum national d’Histoire naturelle, CP26 Paris cedex 05 France
| | - Philippe Keith
- Unité Biologie des organismes et écosystèmes aquatiques (BOREA), Sorbonne Université, Muséum national d’Histoire naturelle, Université de Caen Normandie, CNRS, IRD, CP26 Université des Antilles Paris France
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11
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12
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Schoenfuss HL, Maie T, Moody KN, Lesteberg KE, Blob RW, Schoenfuss TC. Stairway to heaven: evaluating levels of biological organization correlated with the successful ascent of natural waterfalls in the Hawaiian stream goby Sicyopterus stimpsoni. PLoS One 2013; 8:e84851. [PMID: 24386424 PMCID: PMC3873996 DOI: 10.1371/journal.pone.0084851] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/19/2013] [Indexed: 12/02/2022] Open
Abstract
Selective pressures generated by locomotor challenges act at the level of the individual. However, phenotypic variation among individuals that might convey a selective advantage may occur across any of multiple levels of biological organization. In this study, we test for differences in external morphology, muscle mechanical advantage, muscle fiber type and protein expression among individuals of the waterfall climbing Hawaiian fish Sicyopterus stimpsoni collected from sequential pools increasing in elevation within a single freshwater stream. Despite predictions from previous laboratory studies of morphological selection, few directional morphometric changes in body shape were observed at successively higher elevations. Similarly, lever arm ratios associated with the main pelvic sucker, central to climbing ability in this species, did not differ between elevations. However, among climbing muscles, the adductor pelvicus complex (largely responsible for generating pelvic suction during climbing) contained a significantly greater red muscle fiber content at upstream sites. A proteomic analysis of the adductor pelvicus revealed two-fold increases in expression levels for two respiratory chain proteins (NADH:ubiquinone reductase and cytochrome b) that are essential for aerobic respiration among individuals from successively higher elevations. Assessed collectively, these evaluations reveal phenotypic differences at some, but not all levels of biological organization that are likely the result of selective pressures experienced during climbing.
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Affiliation(s)
- Heiko L. Schoenfuss
- Aquatic Toxicology Laboratory, Saint Cloud State University, Saint Cloud, Minnesota, United States of America
| | - Takashi Maie
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
| | - Kristine N. Moody
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
| | - Kelsey E. Lesteberg
- Aquatic Toxicology Laboratory, Saint Cloud State University, Saint Cloud, Minnesota, United States of America
| | - Richard W. Blob
- Department of Biological Sciences, Clemson University, Clemson, South Carolina, United States of America
| | - Tonya C. Schoenfuss
- Department of Food Science and Nutrition, University of Minnesota, Saint Paul, Minnesota, United States of America
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13
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Kawano SM, Blob RW. Propulsive Forces of Mudskipper Fins and Salamander Limbs during Terrestrial Locomotion: Implications for the Invasion of Land. Integr Comp Biol 2013; 53:283-94. [DOI: 10.1093/icb/ict051] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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