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Takeuchi Y, Hata H, Sasaki M, Mvula A, Mizuhara S, Rusuwa B, Maruyama A. Preying on cyprinid snout warts (pearl organs) as a novel and peculiar habit in the Lake Malawi cichlid Docimodus evelynae. Sci Rep 2024; 14:19300. [PMID: 39198502 PMCID: PMC11358289 DOI: 10.1038/s41598-024-69755-z] [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: 03/17/2024] [Accepted: 08/08/2024] [Indexed: 09/01/2024] Open
Abstract
Cichlid fishes in the African Great Lakes have undergone explosive speciation, acquiring markedly varying ecologies and diets. There are multiple lineages of scale-eating cichlids, and their natural history and evolutionary ecology is only partially understood. We examined the feeding habit of Docimodus evelynae, a known scale eater, in Lake Malawi. The stomach contents of young individuals mainly consisted of unknown 1 mm hard, white warts (> 30%). To clarify the origin of these warts, we conducted an X-ray fluorometer analysis, and found they were rich in sulphur but low in silicon and calcium, suggesting they were epidermal tissues. Histological and morphological analyses revealed they were multicellular and cup-shaped. These characteristics matched only those of the pearl organs of the coexisting cyprinid Labeo cylindricus. DNA was extracted from the warts found in the stomach of five D. evelynae individuals, followed by PCR using primers targeting the partial COI gene of L. cylindricus. The resulting sequences exhibited 98% similarity to those of L. cylindricus. Pearl organs, never reported as a primary food for fish, could offer a substantial nutritional source based on calorific calculations. Understanding how this peculiar diet is foraged is essential for full comprehension of the food-web structure in this lake.
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Affiliation(s)
- Yuichi Takeuchi
- Graduate School of Life Science, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo, 060-0810, Japan.
| | - Hiroki Hata
- Graduate School of Science and Engineering, Ehime University, 2-5 Bunkyocho, Matsuyama, Ehime, 790-8577, Japan
| | - Mizuki Sasaki
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido, 080-8555, Japan
| | - Andrew Mvula
- Faculty of Science and Technology, Ryukoku University, Yokotani 1-5 Seta-Oe, Otsu, Shiga, 520-2194, Japan
| | - Shinji Mizuhara
- Faculty of Science and Technology, Ryukoku University, Yokotani 1-5 Seta-Oe, Otsu, Shiga, 520-2194, Japan
| | - Bosco Rusuwa
- Department of Biology, Chancellor College, University of Malawi, Zomba, Malawi
| | - Atsushi Maruyama
- Faculty of Science and Technology, Ryukoku University, Yokotani 1-5 Seta-Oe, Otsu, Shiga, 520-2194, Japan
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Tan A, St John M, Chau D, Clair C, Chan H, Holzman R, Martin CH. A multi-peak performance landscape for scale biting in an adaptive radiation of pupfishes. J Exp Biol 2024; 227:jeb247615. [PMID: 39054887 DOI: 10.1242/jeb.247615] [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: 02/23/2024] [Accepted: 07/19/2024] [Indexed: 07/27/2024]
Abstract
The physical interactions between organisms and their environment ultimately shape diversification rates, but the contributions of biomechanics to evolutionary divergence are frequently overlooked. Here, we estimated a performance landscape for biting in an adaptive radiation of Cyprinodon pupfishes, including scale-biting and molluscivore specialists, and compared performance peaks with previous estimates of the fitness landscape in this system. We used high-speed video to film feeding strikes on gelatin cubes by scale eater, molluscivore, generalist and hybrid pupfishes and measured bite dimensions. We then measured five kinematic variables from 227 strikes using the SLEAP machine-learning model. We found a complex performance landscape with two distinct peaks best predicted gel-biting performance, corresponding to a significant non-linear interaction between peak gape and peak jaw protrusion. Only scale eaters and their hybrids were able to perform strikes within the highest performance peak, characterized by larger peak gapes and greater jaw protrusion. A performance valley separated this peak from a lower performance peak accessible to all species, characterized by smaller peak gapes and less jaw protrusion. However, most individuals exhibited substantial variation in strike kinematics and species could not be reliably distinguished by their strikes, indicating many-to-many mapping of morphology to performance. The two performance peaks observed in the lab were partially consistent with estimates of a two-peak fitness landscape measured in the wild, with the exception of the new performance peak for scale eaters. We thus reveal a new bimodal non-linear biomechanical model that connects morphology to performance to fitness in a sympatric radiation of trophic niche specialists.
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Affiliation(s)
- Anson Tan
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720-3140, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michelle St John
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Dylan Chau
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720-3140, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Chloe Clair
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720-3140, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - HoWan Chan
- Department of BioSciences, Rice University, Houston, TX 77005, USA
| | - Roi Holzman
- School of Zoology, Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
- Inter-University Institute for Marine Sciences, Eilat 8810302, Israel
| | - Christopher H Martin
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720-3140, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, CA 94720, USA
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3
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Cohen KE, Fitzpatrick AR, Huie JM. Dental Dynamics: A Fast New Tool for Quantifying Tooth and Jaw Biomechanics in 3D Slicer. Integr Org Biol 2024; 6:obae015. [PMID: 39045422 PMCID: PMC11263487 DOI: 10.1093/iob/obae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 02/07/2024] [Accepted: 05/08/2024] [Indexed: 07/25/2024] Open
Abstract
Teeth reveal how organisms interact with their environment. Biologists have long looked at the diverse form and function of teeth to study the evolution of feeding, fighting, and development. The exponential rise in the quantity and accessibility of computed tomography (CT) data has enabled morphologists to study teeth at finer resolutions and larger macroevolutionary scales. Measuring tooth function is no easy task, in fact, much of our mechanical understanding is derived from dental shape. Categorical descriptors of tooth shape such as morphological homodonty and heterodonty, overlook nuances in function by reducing tooth diversity for comparative analysis. The functional homodonty method quantitatively assesses the functional diversity of whole dentitions from tooth shape. This method uses tooth surface area and position to calculate the transmission of stress and estimates a threshold for functionally homodont teeth through bootstrapping and clustering techniques. However, some vertebrates have hundreds or thousands of teeth and measuring the shape and function of every individual tooth can be a painstaking task. Here, we present Dental Dynamics, a module for 3D Slicer that allows for the fast and precise quantification of dentitions and jaws. The tool automates the calculation of several tooth traits classically used to describe form and function (i.e., aspect ratio, mechanical advantage, force, etc.). To demonstrate the usefulness of our module we used Dental Dynamics to quantify 780 teeth across 20 salamanders that exhibit diverse ecologies. We coupled these data with the functional homodonty method to investigate the hypothesis that arboreal Aneides salamanders have novel tooth functions. Dental Dynamics provides a new and fast way to measure teeth and increases the accessibility of the functional homodonty method. We hope Dental Dynamics will encourage further theoretical and methodological development for quantifying and studying teeth.
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Affiliation(s)
- K E Cohen
- California State University Fullerton, Biological Science, Fullerton, CA 98231, USA
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
- University of Florida, Museum of Natural History, Gainesville, FL 32611, USA
| | - A R Fitzpatrick
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - J M Huie
- Department of Biology, The George Washington University, Washington, DC 20052, USA
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Claeson KM, Sidlauskas BL, Troll R, Prescott ZM, Davis EB. From sabers to spikes: A newfangled reconstruction of the ancient, giant, sexually dimorphic Pacific salmon, †Oncorhynchus rastrosus (SALMONINAE: SALMONINI). PLoS One 2024; 19:e0300252. [PMID: 38656950 PMCID: PMC11042722 DOI: 10.1371/journal.pone.0300252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/24/2024] [Indexed: 04/26/2024] Open
Abstract
The impressive †Oncorhynchus rastrosus of the Pacific Northwest's Miocene and Pliocene eras was the largest salmonid ever to live. It sported a hypertrophied premaxilla with a pair of enlarged teeth which the original describers reconstructed as projecting ventrally into the mouth, leading them to assign the species to "Smilodonichthys," a genus now in synonymy. Through CT reconstruction of the holotype and newly collected specimens, we demonstrate that the famed teeth projected laterally like tusks, not ventrally like sabers or fangs. We also expand the original description to characterize sexual dimorphism in mature, breeding individuals. Male and female †Oncorhynchus rastrosus differ in the form of the vomer, rostro-dermethmoid-supraethmoid, and dentary, much as do other extant species of Oncorhynchus. Male specimens possess a more elongate vomer than do females, and female vomers have concave ventral surfaces and prominent median dorsal keels. The dentary of females has no evidence of a kype, though some specimens of †O. rastrosus have a non-uniform density mesial to the tooth bed, which we interpret as a male kype. Unlike extant Oncorhynchus, male and female †O. rastrosus do not differ in premaxilla shape. Because male and females possess hypertrophied premaxillae and lateral premaxillary spikes, the former common name "Sabertoothed Salmon" no longer reflects our understanding of the species' morphology. Accordingly, we redub †O. rastrosus the Spike-Toothed Salmon and postulate that its spikes were multifunctional, serving as defense against predators, in agonism against conspecifics, and as a practical aid to nest construction.
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Affiliation(s)
- Kerin M. Claeson
- Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, Pennsylvania, United States of America
| | - Brian L. Sidlauskas
- Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, Oregon, United States of America
| | - Ray Troll
- Troll Art Studios, Ketchikan, Alaska, United States of America
| | | | - Edward B. Davis
- Museum of Natural and Cultural History and Department of Earth Sciences, University of Oregon, Eugene, Oregon, United States of America
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5
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Tan A, St. John M, Chau D, Clair C, Chan H, Holzman R, Martin CH. Multiple performance peaks for scale-biting in an adaptive radiation of pupfishes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.22.573139. [PMID: 38187684 PMCID: PMC10769438 DOI: 10.1101/2023.12.22.573139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The physical interactions between organisms and their environment ultimately shape their rate of speciation and adaptive radiation, but the contributions of biomechanics to evolutionary divergence are frequently overlooked. Here we investigated an adaptive radiation of Cyprinodon pupfishes to measure the relationship between feeding kinematics and performance during adaptation to a novel trophic niche, lepidophagy, in which a predator removes only the scales, mucus, and sometimes tissue from their prey using scraping and biting attacks. We used high-speed video to film scale-biting strikes on gelatin cubes by scale-eater, molluscivore, generalist, and hybrid pupfishes and subsequently measured the dimensions of each bite. We then trained the SLEAP machine-learning animal tracking model to measure kinematic landmarks and automatically scored over 100,000 frames from 227 recorded strikes. Scale-eaters exhibited increased peak gape and greater bite length; however, substantial within-individual kinematic variation resulted in poor discrimination of strikes by species or strike type. Nonetheless, a complex performance landscape with two distinct peaks best predicted gel-biting performance, corresponding to a significant nonlinear interaction between peak gape and peak jaw protrusion in which scale-eaters and their hybrids occupied a second performance peak requiring larger peak gape and greater jaw protrusion. A bite performance valley separating scale-eaters from other species may have contributed to their rapid evolution and is consistent with multiple estimates of a multi-peak fitness landscape in the wild. We thus present an efficient deep-learning automated pipeline for kinematic analyses of feeding strikes and a new biomechanical model for understanding the performance and rapid evolution of a rare trophic niche.
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Affiliation(s)
- Anson Tan
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
| | | | - Dylan Chau
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
| | - Chloe Clair
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
| | | | - Roi Holzman
- School of Zoology, Tel Aviv University, Eilat, Israel
- Inter-University Institute for Marine Sciences, Eilat, Israel
| | - Christopher H. Martin
- Department of Integrative Biology, University of California, Berkeley
- Museum of Vertebrate Zoology, University of California, Berkeley
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6
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Carscadden KA, Batstone RT, Hauser FE. Origins and evolution of biological novelty. Biol Rev Camb Philos Soc 2023; 98:1472-1491. [PMID: 37056155 DOI: 10.1111/brv.12963] [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: 01/28/2022] [Revised: 03/30/2023] [Accepted: 04/03/2023] [Indexed: 04/15/2023]
Abstract
Understanding the origins and impacts of novel traits has been a perennial interest in many realms of ecology and evolutionary biology. Here, we build on previous evolutionary and philosophical treatments of this subject to encompass novelties across biological scales and eco-evolutionary perspectives. By defining novelties as new features at one biological scale that have emergent effects at other biological scales, we incorporate many forms of novelty that have previously been treated in isolation (such as novelty from genetic mutations, new developmental pathways, new morphological features, and new species). Our perspective is based on the fundamental idea that the emergence of a novelty, at any biological scale, depends on its environmental and genetic context. Through this lens, we outline a broad array of generative mechanisms underlying novelty and highlight how genomic tools are transforming our understanding of the origins of novelty. Lastly, we present several case studies to illustrate how novelties across biological scales and systems can be understood based on common mechanisms of change and their environmental and genetic contexts. Specifically, we highlight how gene duplication contributes to the evolution of new complex structures in visual systems; how genetic exchange in symbiosis alters functions of both host and symbiont, resulting in a novel organism; and how hybridisation between species can generate new species with new niches.
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Affiliation(s)
- Kelly A Carscadden
- Department of Ecology and Evolutionary Biology, University of Colorado Boulder, 1900 Pleasant St, Boulder, CO, 80309, USA
| | - Rebecca T Batstone
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, IL, 61801, USA
| | - Frances E Hauser
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, M1C 1A4, Canada
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7
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Heiple Z, Huie JM, Medeiros APM, Hart PB, Goatley CHR, Arcila D, Miller EC. Many ways to build an angler: diversity of feeding morphologies in a deep-sea evolutionary radiation. Biol Lett 2023; 19:20230049. [PMID: 37376854 PMCID: PMC10300507 DOI: 10.1098/rsbl.2023.0049] [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: 02/01/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023] Open
Abstract
Almost nothing is known about the diets of bathypelagic fishes, but functional morphology can provide useful tools to infer ecology. Here we quantify variation in jaw and tooth morphologies across anglerfishes (Lophiiformes), a clade spanning shallow and deep-sea habitats. Deep-sea ceratioid anglerfishes are considered dietary generalists due to the necessity of opportunistic feeding in the food-limited bathypelagic zone. We found unexpected diversity in the trophic morphologies of ceratioid anglerfishes. Ceratioid jaws span a functional continuum ranging from species with numerous stout teeth, a relatively slow but forceful bite, and high jaw protrusibility at one end (characteristics shared with benthic anglerfishes) to species with long fang-like teeth, a fast but weak bite and low jaw protrusibility at the other end (including a unique 'wolftrap' phenotype). Our finding of high morphological diversity seems to be at odds with ecological generality, reminiscent of Liem's paradox (morphological specialization allowing organisms to have broader niches). Another possible explanation is that diverse ceratioid functional morphologies may yield similar trophic success (many-to-one mapping of morphology to diet), allowing diversity to arise through neutral evolutionary processes. Our results highlight that there are many ways to be a successful predator in the deep sea.
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Affiliation(s)
- Zach Heiple
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
- Department of Ichthyology, Sam Noble Oklahoma Museum of Natural History, Norman, OK 73072, USA
| | - Jonathan M. Huie
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Aline P. M. Medeiros
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
- Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Paraíba, João Pessoa 58051-900, Brazil
| | - Pamela B. Hart
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
- Department of Ichthyology, Sam Noble Oklahoma Museum of Natural History, Norman, OK 73072, USA
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, USA
| | - Christopher H. R. Goatley
- School of Ocean and Earth Science, National Oceanography Centre, University of Southampton, Southampton, Hampshire SO14 3ZH, UK
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195, USA
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW 2010, Australia
| | - Dahiana Arcila
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
- Department of Ichthyology, Sam Noble Oklahoma Museum of Natural History, Norman, OK 73072, USA
| | - Elizabeth Christina Miller
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
- Department of Ichthyology, Sam Noble Oklahoma Museum of Natural History, Norman, OK 73072, USA
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA
- Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195, USA
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Kolmann MA, Nagesan RS, Andrews JV, Borstein SR, Figueroa RT, Singer RA, Friedman M, López-Fernández H. DiceCT for fishes: recommendations for pairing iodine contrast agents with μCT to visualize soft tissues in fishes. JOURNAL OF FISH BIOLOGY 2023; 102:893-903. [PMID: 36647819 DOI: 10.1111/jfb.15320] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
Computed tomography (CT) scanning and other high-throughput three-dimensional (3D) visualization tools are transforming the ways we study morphology, ecology and evolutionary biology research beyond generating vast digital repositories of anatomical data. Contrast-enhanced chemical staining methods, which render soft tissues radio-opaque when coupled with CT scanning, encompass several approaches that are growing in popularity and versatility. Of these, the various diceCT techniques that use an iodine-based solution like Lugol's have provided access to an array of morphological data sets spanning extant vertebrate lineages. This contribution outlines straightforward means for applying diceCT techniques to preserved museum specimens of cartilaginous and bony fishes, collectively representing half of vertebrate species diversity. This study contrasts the benefits of using either aqueous or ethylic Lugol's solutions and reports few differences between these methods with respect to the time required to achieve optimal tissue contrast. It also explores differences in minimum stain duration required for different body sizes and shapes and provides recommendations for staining specimens individually or in small batches. As reported by earlier studies, the authors note a decrease in pH during staining with either aqueous or ethylic Lugol's. Nonetheless, they could not replicate the drastic declines in pH reported elsewhere. They provide recommendations for researchers and collections staff on how to incorporate diceCT into existing curatorial practices, while offsetting risk to specimens. Finally, they outline how diceCT with Lugol's can aid ichthyologists of all kinds in visualizing anatomical structures of interest: from brains and gizzards to gas bladders and pharyngeal jaw muscles.
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Affiliation(s)
- Matthew A Kolmann
- University of Michigan Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Biology, University of Louisville, Louisville, Kentucky, USA
| | - Ramon S Nagesan
- Department of Ecology & Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, USA
| | - James V Andrews
- University of Michigan Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel R Borstein
- Department of Ecology & Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, USA
| | - Rodrigo Tinoco Figueroa
- University of Michigan Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Randal A Singer
- Department of Ecology & Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, USA
| | - Matt Friedman
- University of Michigan Museum of Paleontology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Hernán López-Fernández
- Department of Ecology & Evolutionary Biology and Museum of Zoology, University of Michigan, Ann Arbor, Michigan, USA
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9
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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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10
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Wynd B, Abdala F, Nesbitt SJ. Ontogenetic growth in the crania of Exaeretodon argentinus (Synapsida: Cynodontia) captures a dietary shift. PeerJ 2022; 10:e14196. [PMID: 36299507 PMCID: PMC9590418 DOI: 10.7717/peerj.14196] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 09/15/2022] [Indexed: 01/26/2023] Open
Abstract
Background An ontogenetic niche shift in vertebrates is a common occurrence where ecology shifts with morphological changes throughout growth. How ecology shifts over a vertebrate's lifetime is often reconstructed in extant species-by combining observational and skeletal data from growth series of the same species-because interactions between organisms and their environment can be observed directly. However, reconstructing shifts using extinct vertebrates is difficult and requires well-sampled growth series, specimens with relatively complete preservation, and easily observable skeletal traits associated with ecologies suspected to change throughout growth, such as diet. Methods To reconstruct ecological changes throughout the growth of a stem-mammal, we describe changes associated with dietary ecology in a growth series of crania of the large-bodied (∼2 m in length) and herbivorous form, Exaeretodon argentinus (Cynodontia: Traversodontidae) from the Late Triassic Ischigualasto Formation, San Juan, Argentina. Nearly all specimens were deformed by taphonomic processes, so we reconstructed allometric slope using a generalized linear mixed effects model with distortion as a random effect. Results Under a mixed effects model, we find that throughout growth, E. argentinus reduced the relative length of the palate, postcanine series, orbits, and basicranium, and expanded the relative length of the temporal region and the height of the zygomatic arch. The allometric relationship between the zygomatic arch and temporal region with the total length of the skull approximate the rate of growth for feeding musculature. Based on a higher allometric slope, the zygoma height is growing relatively faster than the length of the temporal region. The higher rate of change in the zygoma may suggest that smaller individuals had a crushing-dominated feeding style that transitioned into a chewing-dominated feeding style in larger individuals, suggesting a dietary shift from possible faunivory to a more plant-dominated diet. Dietary differentiation throughout development is further supported by an increase in sutural complexity and a shift in the orientation of microwear anisotropy between small and large individuals of E. argentinus. A developmental transition in the feeding ecology of E. argentinus is reflective of the reconstructed dietary transition across Gomphodontia, wherein the earliest-diverging species are inferred as omnivorous and the well-nested traversodontids are inferred as herbivorous, potentially suggesting that faunivory in immature individuals of the herbivorous Traversodontidae may be plesiomorphic for the clade.
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Affiliation(s)
- Brenen Wynd
- Department of Geosciences, Virginia Tech, Blacksburg, VA, United States of America
| | - Fernando Abdala
- CONICET-Fundación Miguel Lillo, Unidad Ejecutora Lillo, San Miguel de Tucumán, Tucumán, Argentina
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| | - Sterling J. Nesbitt
- Department of Geosciences, Virginia Tech, Blacksburg, VA, United States of America
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11
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Melo BF, Sidlauskas BL, Near TJ, Roxo FF, Ghezelayagh A, Ochoa LE, Stiassny MLJ, Arroyave J, Chang J, Faircloth BC, MacGuigan DJ, Harrington RC, Benine RC, Burns MD, Hoekzema K, Sanches NC, Maldonado-Ocampo JA, Castro RMC, Foresti F, Alfaro ME, Oliveira C. Accelerated Diversification Explains the Exceptional Species Richness of Tropical Characoid Fishes. Syst Biol 2021; 71:78-92. [PMID: 34097063 DOI: 10.1093/sysbio/syab040] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 06/01/2021] [Accepted: 06/04/2021] [Indexed: 11/12/2022] Open
Abstract
The Neotropics harbor the most species-rich freshwater fish fauna on the planet, but the timing of that exceptional diversification remains unclear. Did the Neotropics accumulate species steadily throughout their long history, or attain their remarkable diversity recently? Biologists have long debated the relative support for these museum and cradle hypotheses, but few phylogenies of megadiverse tropical clades have included sufficient taxa to distinguish between them. We used 1,288 ultraconserved element loci (UCE) spanning 293 species, 211 genera and 21 families of characoid fishes to reconstruct a new, fossil-calibrated phylogeny and infer the most likely diversification scenario for a clade that includes a third of Neotropical fish diversity. This phylogeny implies paraphyly of the traditional delimitation of Characiformes because it resolves the largely Neotropical Characoidei as the sister lineage of Siluriformes (catfishes), rather than the African Citharinodei. Time-calibrated phylogenies indicate an ancient origin of major characoid lineages and reveal a much more recent emergence of most characoid species. Diversification rate analyses infer increased speciation and decreased extinction rates during the Oligocene at around 30 million years ago (Ma) during a period of mega-wetland formation in the proto-Orinoco-Amazonas. Three species-rich and ecomorphologically diverse lineages (Anostomidae, Serrasalmidae, and Characidae) that originated more than 60 Ma in the Paleocene experienced particularly notable bursts of Oligocene diversification and now account collectively for 68% of the approximately 2,150 species of Characoidei. In addition to paleogeographic changes, we discuss potential accelerants of diversification in these three lineages. While the Neotropics accumulated a museum of ecomorphologically diverse characoid lineages long ago, this geologically dynamic region also cradled a much more recent birth of remarkable species-level diversity.
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Affiliation(s)
- Bruno F Melo
- Dept of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 16818-689, Brazil
| | - Brian L Sidlauskas
- Dept of Fisheries and Wildlife, Oregon State University, Corvallis, OR, 97331, USA
| | - Thomas J Near
- Dept of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| | - Fabio F Roxo
- Sector of Zoology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 18618-689, Brazil
| | - Ava Ghezelayagh
- Dept of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| | - Luz E Ochoa
- Dept of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 16818-689, Brazil.,Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Palmira, Valle del Cauca, 763547, Colombia
| | - Melanie L J Stiassny
- Dept of Ichthyology, American Museum of Natural History, New York, NY, 10024, USA
| | - Jairo Arroyave
- Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, 04510, México
| | - Jonathan Chang
- School of Biological Sciences, Monash University, Melbourne, VIC, 3800, Australia
| | - Brant C Faircloth
- Dept of Biological Sciences and Museum of Natural Science, Louisiana State University, Baton Rouge, LA, 70803, USA
| | - Daniel J MacGuigan
- Dept of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| | - Richard C Harrington
- Dept of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA
| | - Ricardo C Benine
- Sector of Zoology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 18618-689, Brazil
| | - Michael D Burns
- Cornell Lab of Ornithology, Cornell University Museum of Vertebrates, Ithaca, NY, 14850, USA
| | - Kendra Hoekzema
- Dept of Fisheries and Wildlife, Oregon State University, Corvallis, OR, 97331, USA
| | - Natalia C Sanches
- Dept of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 16818-689, Brazil
| | - Javier A Maldonado-Ocampo
- Dept de Biología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, DC, Colombia (in memoriam)
| | - Ricardo M C Castro
- Faculdade de Filosofia, Ciências e Letras, Universidade de São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | - Fausto Foresti
- Dept of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 16818-689, Brazil
| | - Michael E Alfaro
- Dept of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA
| | - Claudio Oliveira
- Dept of Structural and Functional Biology, Institute of Biosciences, São Paulo State University, Botucatu, SP, 16818-689, Brazil
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12
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Martin CH, Gould KJ. Surprising spatiotemporal stability of a multi-peak fitness landscape revealed by independent field experiments measuring hybrid fitness. Evol Lett 2020; 4:530-544. [PMID: 33312688 PMCID: PMC7719547 DOI: 10.1002/evl3.195] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 07/23/2020] [Accepted: 09/14/2020] [Indexed: 12/14/2022] Open
Abstract
The effect of the environment on fitness in natural populations is a fundamental question in evolutionary biology. However, experimental manipulations of both environment and phenotype at the same time are rare. Thus, the relative importance of the competitive environment versus intrinsic organismal performance in shaping the location, height, and fluidity of fitness peaks and valleys remains largely unknown. Here, we experimentally tested the effect of competitor frequency on the complex fitness landscape driving adaptive radiation of a generalist and two trophic specialist pupfishes, a scale-eater and molluscivore, endemic to hypersaline lakes on San Salvador Island (SSI), Bahamas. We manipulated phenotypes, by generating 3407 F4/F5 lab-reared hybrids, and competitive environment, by altering the frequency of rare transgressive hybrids between field enclosures in two independent lake populations. We then tracked hybrid survival and growth rates across these four field enclosures for 3-11 months. In contrast to competitive speciation theory, we found no evidence that the frequency of hybrid phenotypes affected their survival. Instead, we observed a strikingly similar fitness landscape to a previous independent field experiment, each supporting multiple fitness peaks for generalist and molluscivore phenotypes and a large fitness valley isolating the divergent scale-eater phenotype. These features of the fitness landscape were stable across manipulated competitive environments, multivariate trait axes, and spatiotemporal heterogeneity. We suggest that absolute performance constraints and divergent gene regulatory networks shape macroevolutionary (interspecific) fitness landscapes in addition to microevolutionary (intraspecific) competitive dynamics. This interplay between organism and environment underlies static and dynamic features of the adaptive landscape.
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Affiliation(s)
- Christopher H. Martin
- Department of Integrative BiologyUniversity of California, BerkeleyBerkeleyCalifornia94720
- Museum of Vertebrate ZoologyUniversity of California, BerkeleyBerkeleyCalifornia94720
| | - Katelyn J. Gould
- Department of BiologyUniversity of North Carolina at Chapel HillChapel HillNorth Carolina27515
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13
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Kolmann MA, Hughes LC, Hernandez LP, Arcila D, Betancur-R R, Sabaj MH, López-Fernández H, Ortí G. Phylogenomics of Piranhas and Pacus (Serrasalmidae) Uncovers How Dietary Convergence and Parallelism Obfuscate Traditional Morphological Taxonomy. Syst Biol 2020; 70:576-592. [PMID: 32785670 DOI: 10.1093/sysbio/syaa065] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 07/30/2020] [Accepted: 08/03/2020] [Indexed: 02/06/2023] Open
Abstract
The Amazon and neighboring South American river basins harbor the world's most diverse assemblages of freshwater fishes. One of the most prominent South American fish families is the Serrasalmidae (pacus and piranhas), found in nearly every continental basin. Serrasalmids are keystone ecological taxa, being some of the top riverine predators as well as the primary seed dispersers in the flooded forest. Despite their widespread occurrence and notable ecologies, serrasalmid evolutionary history and systematics are controversial. For example, the sister taxon to serrasalmids is contentious, the relationships of major clades within the family are inconsistent across different methodologies, and half of the extant serrasalmid genera are suggested to be non-monophyletic. We analyzed exon capture to reexamine the evolutionary relationships among 63 (of 99) species across all 16 serrasalmid genera and their nearest outgroups, including multiple individuals per species to account for cryptic lineages. To reconstruct the timeline of serrasalmid diversification, we time-calibrated this phylogeny using two different fossil-calibration schemes to account for uncertainty in taxonomy with respect to fossil teeth. Finally, we analyzed diet evolution across the family and comment on associated changes in dentition, highlighting the ecomorphological diversity within serrasalmids. We document widespread non-monophyly of genera within Myleinae, as well as between Serrasalmus and Pristobrycon, and propose that reliance on traits like teeth to distinguish among genera is confounded by ecological homoplasy, especially among herbivorous and omnivorous taxa. We clarify the relationships among all serrasalmid genera, propose new subfamily affiliations, and support hemiodontids as the sister taxon to Serrasalmidae. [Characiformes; exon capture; ichthyochory; molecular time-calibration; piscivory.].
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Affiliation(s)
- M A Kolmann
- Dept of Biological Sciences, George Washington University, 2029 G St. NW, Washington, DC 20052, USA.,Dept of Natural History, Royal Ontario Museum, 100 Queens Park, Toronto, ON M5S 2C6, Canada
| | - L C Hughes
- Dept of Biological Sciences, George Washington University, 2029 G St. NW, Washington, DC 20052, USA.,Dept of Ichthyology, Smithsonian National Museum of Natural History, 10th St. & Constitution Ave. NW, Washington, DC 20560, USA
| | - L P Hernandez
- Dept of Biological Sciences, George Washington University, 2029 G St. NW, Washington, DC 20052, USA
| | - D Arcila
- Dept of Ichthyology, Sam Noble Museum, 2401 Chautauqua Ave, Norman, OK 73072, USA.,Dept of Biology, University of Oklahoma, 660 Parrington Oval, Norman, OK 73019, USA
| | - R Betancur-R
- Dept of Ichthyology, Sam Noble Museum, 2401 Chautauqua Ave, Norman, OK 73072, USA.,Dept of Biology, University of Oklahoma, 660 Parrington Oval, Norman, OK 73019, USA
| | - M H Sabaj
- Dept of Ichthyology, The Academy of Natural Sciences of Drexel University, 1900 Benjamin Franklin Pkwy, Philadelphia, PA 19103, USA
| | - H López-Fernández
- Museum of Zoology, University of Michigan, 1105 North University Dr., Ann Arbor, MI 48109, USA
| | - G Ortí
- Dept of Biological Sciences, George Washington University, 2029 G St. NW, Washington, DC 20052, USA.,Dept of Ichthyology, Smithsonian National Museum of Natural History, 10th St. & Constitution Ave. NW, Washington, DC 20560, USA
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14
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Buser TJ, Boyd OF, Cortés Á, Donatelli CM, Kolmann MA, Luparell JL, Pfeiffenberger JA, Sidlauskas BL, Summers AP. The Natural Historian's Guide to the CT Galaxy: Step-by-Step Instructions for Preparing and Analyzing Computed Tomographic (CT) Data Using Cross-Platform, Open Access Software. Integr Org Biol 2020; 2:obaa009. [PMID: 33791553 PMCID: PMC7671151 DOI: 10.1093/iob/obaa009] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The decreasing cost of acquiring computed tomographic (CT) data has fueled a global effort to digitize the anatomy of museum specimens. This effort has produced a wealth of open access digital three-dimensional (3D) models of anatomy available to anyone with access to the Internet. The potential applications of these data are broad, ranging from 3D printing for purely educational purposes to the development of highly advanced biomechanical models of anatomical structures. However, while virtually anyone can access these digital data, relatively few have the training to easily derive a desirable product (e.g., a 3D visualization of an anatomical structure) from them. Here, we present a workflow based on free, open source, cross-platform software for processing CT data. We provide step-by-step instructions that start with acquiring CT data from a new reconstruction or an open access repository, and progress through visualizing, measuring, landmarking, and constructing digital 3D models of anatomical structures. We also include instructions for digital dissection, data reduction, and exporting data for use in downstream applications such as 3D printing. Finally, we provide Supplementary Videos and workflows that demonstrate how the workflow facilitates five specific applications: measuring functional traits associated with feeding, digitally isolating anatomical structures, isolating regions of interest using semi-automated segmentation, collecting data with simple visual tools, and reducing file size and converting file type of a 3D model.
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Affiliation(s)
- T J Buser
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - O F Boyd
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Á Cortés
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - C M Donatelli
- Department of Biology, University of Ottawa, Ottawa, ON, USA
| | - M A Kolmann
- Department of Biological Sciences, George Washington University, Washington, DC, USA
| | - J L Luparell
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | | | - B L Sidlauskas
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | - A P Summers
- Department of Biology and SAFS, University of Washington, Friday Harbor Laboratories, Friday Harbor, Washington, DC, USA
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15
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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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16
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Huie JM, Thacker CE, Tornabene L. Co-evolution of cleaning and feeding morphology in western Atlantic and eastern Pacific gobies. Evolution 2019; 74:419-433. [PMID: 31876289 DOI: 10.1111/evo.13904] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 11/22/2019] [Accepted: 11/25/2019] [Indexed: 11/30/2022]
Abstract
Cleaning symbioses are mutualistic relationships where cleaners remove and consume ectoparasites from their clients. Cleaning behavior is rare in fishes and is a highly specialized feeding strategy only observed in around 200 species. Cleaner fishes vary in their degree of specialization, ranging from species that clean as juveniles or facultatively as adults, to nearly obligate or dedicated cleaners. Here, we investigate whether these different levels of trophic specialization correspond with similar changes in feeding morphology. Specifically, we model the evolution of cleaning behavior across the family Gobiidae, which contains the most speciose radiation of dedicated and facultative cleaner fishes. We compared the cranial morphology and dentition of cleaners and non-cleaners across the phylogeny of cleaning gobies and found that facultative cleaners independently evolved four times and have converged on an intermediate morphology relative to that of dedicated cleaners and non-cleaning generalists. This is consistent with their more flexible feeding habits. Cleaner gobies also possess a distinct tooth morphology, which suggests they are adapted for scraping parasites off their clients and show little similarity to other cleaner clades. We propose that evolutionary history and pre-adaptation underlie the morphological and ecological diversification of cleaner fishes.
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Affiliation(s)
- Jonathan M Huie
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St, Seattle, Washington, 98195
| | - Christine E Thacker
- Santa Barbara Museum of Natural History, 2559 Puesta del Sol, Santa Barbara, California, 93105.,Natural History Museum of Los Angeles County, 900 Exposition Blvd, Los Angeles, California, 90007
| | - Luke Tornabene
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St, Seattle, Washington, 98195.,Burke Museum of Natural History and Culture, 4300 15th Ave NE, Seattle, Washington, 98105
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17
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Phylogenetic relationships and historical biogeography of Oligosarcus (Teleostei: Characidae): Examining riverine landscape evolution in southeastern South America. Mol Phylogenet Evol 2019; 140:106604. [DOI: 10.1016/j.ympev.2019.106604] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 12/22/2022]
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18
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Buser TJ, Finnegan DL, Summers AP, Kolmann MA. Have Niche, Will Travel. New Means of Linking Diet and Ecomorphology Reveals Niche Conservatism in Freshwater Cottoid Fishes. Integr Org Biol 2019; 1:obz023. [PMID: 33791537 PMCID: PMC7671106 DOI: 10.1093/iob/obz023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Evolutionary transitions between habitats have been catalysts for some of the most stunning examples of adaptive diversification, with novel niches and new resources providing ecological opportunity for such radiations. In aquatic animals, transitions from saltwater to freshwater habitats are rare, but occur often enough that in the Neotropics for example, marine-derived fishes contribute noticeably to regional ichthyofaunal diversity. Here, we investigate how morphology has evolved in a group of temperate fishes that contain a marine to freshwater transition: the sculpins (Percomorpha; Cottoidea). We devised a novel method for classifying dietary niche and relating functional aspects of prey to their predators. Coupled with functional measurements of the jaw apparatus in cottoids, we explored whether freshwater sculpins have fundamentally changed their niche after invading freshwater (niche lability) or if they retain a niche similar to their marine cousins (niche conservatism). Freshwater sculpins exhibit both phylogeographical and ecological signals of phylogenetic niche conservatism, meaning that regardless of habitat, sculpins fill similar niche roles in either saltwater or freshwater. Rather than competition guiding niche conservatism in freshwater cottoids, we argue that strong intrinsic constraints on morphological and ecological evolution are at play, contra to other studies of diversification in marine-derived freshwater fishes. However, several intertidal and subtidal sculpins as well as several pelagic freshwater species from Lake Baikal show remarkable departures from the typical sculpin bauplan. Our method of prey categorization provides an explicit, quantitative means of classifying dietary niche for macroevolutionary studies, rather than relying on somewhat arbitrary means used in previous literature.
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Affiliation(s)
- T J Buser
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97321, USA
| | - D L Finnegan
- Department of Biology, Western Washington University, Bellingham, WA 98225, USA
| | - A P Summers
- Department of Biology and SAFS, University of Washington s Friday Harbor Laboratories, Friday Harbor, WA 98250, USA
| | - M A Kolmann
- Department of Biology and SAFS, University of Washington s Friday Harbor Laboratories, Friday Harbor, WA 98250, USA
- Department of Biological Sciences, George Washington University, Washington, DC 20052, USA
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19
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Kolmann MA, Cohen KE, Bemis KE, Summers AP, Irish FJ, Hernandez LP. Tooth and consequences: Heterodonty and dental replacement in piranhas and pacus (Serrasalmidae). Evol Dev 2019; 21:278-293. [DOI: 10.1111/ede.12306] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Matthew A. Kolmann
- Department of Biological Sciences George Washington University Washington District of Columbia
- Department of Biology, Friday Harbor Laboratories University of Washington Friday Harbor Washington
| | - Karly E. Cohen
- Department of Biological Sciences George Washington University Washington District of Columbia
- Department of Biology, Friday Harbor Laboratories University of Washington Friday Harbor Washington
| | - Katherine E. Bemis
- Fisheries Science, Virginia Institute of Marine Science Gloucester Point Virginia
| | - Adam P. Summers
- Department of Biology, Friday Harbor Laboratories University of Washington Friday Harbor Washington
| | - Frances J. Irish
- Department of Biological Sciences Moravian College Bethlehem Pennsylvania
| | - L. Patricia Hernandez
- Department of Biological Sciences George Washington University Washington District of Columbia
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20
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Martin CH, McGirr JA, Richards EJ, St. John ME. How to Investigate the Origins of Novelty: Insights Gained from Genetic, Behavioral, and Fitness Perspectives. Integr Org Biol 2019; 1:obz018. [PMID: 33791533 PMCID: PMC7671130 DOI: 10.1093/iob/obz018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Biologists are drawn to the most extraordinary adaptations in the natural world, often referred to as evolutionary novelties, yet rarely do we understand the microevolutionary context underlying the origins of novel traits, behaviors, or ecological niches. Here we discuss insights gained into the origins of novelty from a research program spanning biological levels of organization from genotype to fitness in Caribbean pupfishes. We focus on a case study of the origins of novel trophic specialists on San Salvador Island, Bahamas and place this radiation in the context of other rapid radiations. We highlight questions that can be addressed about the origins of novelty at different biological levels, such as measuring the isolation of novel phenotypes on the fitness landscape, locating the spatial and temporal origins of adaptive variation contributing to novelty, detecting dysfunctional gene regulation due to adaptive divergence, and connecting behaviors with novel traits. Evolutionary novelties are rare, almost by definition, and we conclude that integrative case studies can provide insights into this rarity relative to the dynamics of adaptation to more common ecological niches and repeated parallel speciation, such as the relative isolation of novel phenotypes on fitness landscapes and the transient availability of ecological, genetic, and behavioral opportunities.
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Affiliation(s)
- C H Martin
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - J A McGirr
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
| | - E J Richards
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - M E St. John
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
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21
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Huie JM, Summers AP, Kolmann MA. Body shape separates guilds of rheophilic herbivores (Myleinae: Serrasalmidae) better than feeding morphology. PROCEEDINGS OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA 2019. [DOI: 10.1635/053.166.0116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jonathan M. Huie
- School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat St, Seattle, WA 98195, USA
| | - Adam P. Summers
- Friday Harbor Laboratories, University of Washington, 620 University Road, Friday Harbor, WA 98250, USA
| | - Matthew A. Kolmann
- Department of Biological Sciences, George Washington University, 800 22nd St NW, Suite 6000, Washington, DC 20052, USA
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22
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Evans KM, Kim LY, Schubert BA, Albert JS. Ecomorphology of Neotropical Electric Fishes: An Integrative Approach to Testing the Relationships between Form, Function, and Trophic Ecology. Integr Org Biol 2019; 1:obz015. [PMID: 33791530 PMCID: PMC7671154 DOI: 10.1093/iob/obz015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The relationship between form and function is thought to play an integral role in structuring broad-scale patterns of morphological evolution and resource utilization. In ecomorphological studies, mechanical performance is widely understood to constrain the evolution of form and function. However, the relationship between form, function, and resource utilization is less clear. Additionally, seasonal fluctuations in resource availability may further complicate patterns of resource use. How organisms cope with these complexities, and the effect of these factors on broadscale patterns of morphological evolution is also poorly understood. Here we use three-dimensional geometric morphometrics, biomechanics, stable isotope analysis, and gut-content analysis to study trophic evolution in a clade of riverine-adapted electric fishes from a region with high seasonal variability; the Amazon River. We find significant and phylogenetically structured relationships among measures of trophic ecology and skull shape. We also recover a significant relationship between the mechanical advantage of the mandible and trophic position, where species feeding at higher trophic levels have narrower jaws with lower mechanical advantages, and species feeding at lower trophic levels have deeper jaws with higher mechanical advantages. Our results indicate that selection is driving the evolution of mandible shape and performance toward specialization on different trophic ecologies.
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Affiliation(s)
- K M Evans
- College of Food, Agricultural and Natural Resource Sciences, University of Minnesota, 1987 Upper Buford Circle, St. Paul, MN 55108, USA
| | - L Y Kim
- Department of Biology, University of Louisiana at Lafayette, P.O. Box 42451, Lafayette, LA 70504, USA
| | - B A Schubert
- School of Geosciences, University of Louisiana at Lafayette, P.O. Box 43705, Lafayette, LA 70504, USA
| | - J S Albert
- Department of Biology, University of Louisiana at Lafayette, P.O. Box 42451, Lafayette, LA 70504, USA
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23
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Evans KM, Vidal-García M, Tagliacollo VA, Taylor SJ, Fenolio DB. Bony Patchwork: Mosaic Patterns of Evolution in the Skull of Electric Fishes (Apteronotidae: Gymnotiformes). Integr Comp Biol 2019; 59:420-431. [DOI: 10.1093/icb/icz026] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Mosaic evolution refers to the pattern whereby different organismal traits exhibit differential rates of evolution typically due to reduced levels of trait covariation through deep time (i.e., modularity). These differences in rates can be attributed to variation in responses to selective pressures between individual traits. Differential responses to selective pressures also have the potential to facilitate functional specialization, allowing certain traits to track environmental stimuli more closely than others. The teleost skull is a multifunctional structure comprising a complex network of bones and thus an excellent system for which to study mosaic evolution. Here we construct an ultrametric phylogeny for a clade of Neotropical electric fishes (Apteronotidae: Gymnotiformes) and use three-dimensional geometric morphometrics to investigate patterns of mosaic evolution in the skull and jaws. We find strong support for a developmental, three-module hypothesis that consists of the face, braincase, and mandible, and we find that the mandible has evolved four times faster than its neighboring modules. We hypothesize that the functional specialization of the mandible in this group of fishes has allowed it to outpace the face and braincase and evolve in a more decoupled manner. We also hypothesize that this pattern of mosaicism may be widespread across other clades of teleost fishes.
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Affiliation(s)
- Kory M Evans
- College of Food, Agricultural and Natural Resource Sciences, University of Minnesota, 1987 Upper Buford Circle, St. Paul, MN 55108, USA
| | - Marta Vidal-García
- Research School of Biology, Department of Ecology and Evolution, The Australian National University, Canberra, ACT 0200, Australia
| | - Victor A Tagliacollo
- Museu de Zoologia da Universidade de São Paulo, Avenida Nazaré, 481, Ipiranga, 04263-000 São Paulo, Brazil
| | - Samuel J Taylor
- Center for Conservation and Research, 3903 N. St Mary’s Street, San Antonio, TX 78212, USA
| | - Dante B Fenolio
- Center for Conservation and Research, 3903 N. St Mary’s Street, San Antonio, TX 78212, USA
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24
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St. John ME, McGirr JA, Martin CH. The behavioral origins of novelty: did increased aggression lead to scale-eating in pupfishes? Behav Ecol 2019; 30:557-569. [PMID: 30971862 PMCID: PMC6450202 DOI: 10.1093/beheco/ary196] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 11/08/2018] [Accepted: 12/14/2018] [Indexed: 11/13/2022] Open
Abstract
Behavioral changes in a new environment are often assumed to precede the origins of evolutionary novelties. Here, we examined whether an increase in aggression is associated with a novel scale-eating trophic niche within a recent radiation of Cyprinodon pupfishes endemic to San Salvador Island, Bahamas. We measured aggression using multiple behavioral assays and used transcriptomic analyses to identify differentially expressed genes in aggression and other behavioral pathways across 3 sympatric species in the San Salvador radiation (generalist, snail-eating specialist, and scale-eating specialist) and 2 generalist outgroups. Surprisingly, we found increased behavioral aggression and differential expression of aggression-related pathways in both the scale-eating and snail-eating specialists, despite their independent evolutionary origins. Increased behavioral aggression varied across both sex and stimulus context in both species. Our results indicate that aggression is not unique to scale-eating specialists. Instead, selection may increase aggression in other contexts such as niche specialization in general or mate competition. Alternatively, increased aggression may result from indirect selection on craniofacial traits, pigmentation, or metabolism-all traits which are highly divergent, exhibit signs of selective sweeps, and are affected by aggression-related genetic pathways which are differentially expressed in this system. In conclusion, the evolution of a novel predatory trophic niche within a recent adaptive radiation does not have clear-cut behavioral origins as previously assumed, highlighting the multivariate nature of adaptation and the complex integration of behavior with other phenotypic traits.
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Affiliation(s)
| | - Joseph A McGirr
- Department of Biology, University of North Carolina at Chapel Hill, NC, USA
| | - Christopher H Martin
- Department of Biology, University of North Carolina at Chapel Hill, NC, USA
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA
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Burns MD, Sidlauskas BL. Ancient and contingent body shape diversification in a hyperdiverse continental fish radiation. Evolution 2019; 73:569-587. [DOI: 10.1111/evo.13658] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 11/23/2018] [Indexed: 12/22/2022]
Affiliation(s)
- Michael D. Burns
- Department of Fisheries and Wildlife Oregon State University Oregon 97330
| | - Brian L. Sidlauskas
- Department of Fisheries and Wildlife Oregon State University Oregon 97330
- Department of Vertebrate Zoology National Museum of Natural History, Smithsonian Institution Washington District of Columbia 20560
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Evans KM, Bernt MJ, Kolmann MA, Ford KL, Albert JS. Why the long face? Static allometry in the sexually dimorphic phenotypes of Neotropical electric fishes. Zool J Linn Soc 2018. [DOI: 10.1093/zoolinnean/zly076] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
The evolution of sexually dimorphic traits is thought to have marked effects on underlying patterns of static allometry. These traits can negatively affect organismal survivability by creating trade-offs between trait size and performance. Here we use three-dimensional geometric morphometrics to study the static allometry of two species of sexually dimorphic electric fishes (Apteronotus rostratus and Compsaraia samueli) in which mature males grow elongate jaws used in agonistic male–male interactions. We also estimate jaw-closing performance between the sexes of both species to track changes in kinematic transmission associated with the development of sexual weaponry. We find significantly different patterns of static allometry between the sexes of both species, with males exhibiting more positive allometric slopes relative to females. We also find a negative relationship between skull shape and mandibular kinematic transmission in C. samueli, suggesting a trade-off where males with longer faces exhibit lower mechanical advantages, suggesting weaker jaw leverage. In contrast, males and females of A. rostratus exhibit no difference between sexes in mechanical advantage associated with facial elongation.
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Affiliation(s)
- Kory M Evans
- University of Minnesota, Department of Fisheries, Wildlife, and Conservation Biology, & Bell Museum of Natural History, St Paul, MN, USA
| | - Maxwell J Bernt
- University of Louisiana at Lafayette, Department of Biology, Lafayette, LA, USA
| | | | - Kassandra L Ford
- University of Louisiana at Lafayette, Department of Biology, Lafayette, LA, USA
| | - James S Albert
- University of Louisiana at Lafayette, Department of Biology, Lafayette, LA, USA
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