The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Haas Alexander - One of the best experts on this subject based on the ideXlab platform.
-
Fejervarya limnocharis ZMH A05523, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Fejervarya limnocharis Collection number: ZMH A05523 Institution of origin: Zoologisches Museum Hamburg Data: CT volume of unstained specimen Coverage: partial specimen, feet cut Scanner: Skyscan1172 Scanning paramters: 100 kV; 100 µA; filter: Al 0.5 mm Voxel size: 21.34472 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Kaloula pulchra CAS 230419, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Kaloula pulchra Collection number: CAS 230419 Institution of origin: California Academy of Sciences, San Francisco Data: CT volume of unstained specimen Coverage: partial specimen, snout and fingers cut Scanner: Skyscan1172 Scanning paramters: 49 kV; 200 µA; filter: Al 0.5 mm Voxel size: 18.67658 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Microhyla nepenthicola ZMH A11645, unstained CT volume
2020Co-Authors: Beerlink André, Engelkes Karolin, Haas AlexanderAbstract:Species: Microhyla nepenthicola Collection number: ZMH A11645 Institution of origin: Zoologisches Museum Hamburg Data: CT volume of unstained specimen Coverage: full specimen Scanner: YXLON FF20 CT Scanning paramters: 60 kV; 110 µA; filter: no filter Voxel size: 12.6868205127229 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Xenopus laevis laevis ZMH A02374, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Xenopus laevis laevis Collection number: ZMH A02374 Institution of origin: Zoologisches Museum Hamburg Data: CT volume of unstained specimen Coverage: full specimen Scanner: Skyscan1172 Scanning paramters: 100 kV; 100 µA; filter: Al 0.5 mm Voxel size: 26.68090 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Breviceps mossambicus ZMB 83246, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Breviceps mossambicus Collection number: ZMB 83246 Institution of origin: Museum für Naturkunde, Berlin Data: CT volume of unstained specimen Coverage: partial specimen, left fingertips cut Scanner: Skyscan1172 Scanning paramters: 55 kV; 181 µA; filter: Al 0.5 mm Voxel size: 16.53658 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
Engelkes Karolin - One of the best experts on this subject based on the ideXlab platform.
-
Fejervarya limnocharis ZMH A05523, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Fejervarya limnocharis Collection number: ZMH A05523 Institution of origin: Zoologisches Museum Hamburg Data: CT volume of unstained specimen Coverage: partial specimen, feet cut Scanner: Skyscan1172 Scanning paramters: 100 kV; 100 µA; filter: Al 0.5 mm Voxel size: 21.34472 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Kaloula pulchra CAS 230419, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Kaloula pulchra Collection number: CAS 230419 Institution of origin: California Academy of Sciences, San Francisco Data: CT volume of unstained specimen Coverage: partial specimen, snout and fingers cut Scanner: Skyscan1172 Scanning paramters: 49 kV; 200 µA; filter: Al 0.5 mm Voxel size: 18.67658 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Microhyla nepenthicola ZMH A11645, unstained CT volume
2020Co-Authors: Beerlink André, Engelkes Karolin, Haas AlexanderAbstract:Species: Microhyla nepenthicola Collection number: ZMH A11645 Institution of origin: Zoologisches Museum Hamburg Data: CT volume of unstained specimen Coverage: full specimen Scanner: YXLON FF20 CT Scanning paramters: 60 kV; 110 µA; filter: no filter Voxel size: 12.6868205127229 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Xenopus laevis laevis ZMH A02374, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Xenopus laevis laevis Collection number: ZMH A02374 Institution of origin: Zoologisches Museum Hamburg Data: CT volume of unstained specimen Coverage: full specimen Scanner: Skyscan1172 Scanning paramters: 100 kV; 100 µA; filter: Al 0.5 mm Voxel size: 26.68090 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
-
Breviceps mossambicus ZMB 83246, unstained CT volume
2020Co-Authors: Engelkes Karolin, Haas AlexanderAbstract:Species: Breviceps mossambicus Collection number: ZMB 83246 Institution of origin: Museum für Naturkunde, Berlin Data: CT volume of unstained specimen Coverage: partial specimen, left fingertips cut Scanner: Skyscan1172 Scanning paramters: 55 kV; 181 µA; filter: Al 0.5 mm Voxel size: 16.53658 µmDataset used in: Engelkes, K., Kath, L., Kleinteich, T., Hammel, J. U., Beerlink, A., Haas, A. (2020) Ecomorphology of the pectoral girdle in anurans (Amphibia, Anura): Shape diversity and biomechanical considerations. Ecology and Evolution 10(20): 11467–11487. https://doi.org/10.1002/ece3.6784
Peter C Wainwright - One of the best experts on this subject based on the ideXlab platform.
-
Ecomorphology of the eyes and skull in zooplanktivorous labrid fishes
Coral Reefs, 2011Co-Authors: Lars Schmitz, Peter C WainwrightAbstract:Zooplanktivory is one of the most distinct trophic niches in coral reef fishes, and a number of skull traits are widely recognized as being adaptations for feeding in midwater on small planktonic prey. Previous studies have concluded that zooplanktivores have larger eyes for sharper visual acuity, reduced mouth structures to match small prey sizes, and longer gill rakers to help retain captured prey. We tested these three traditional hypotheses plus two novel adaptive hypotheses in labrids, a clade of very diverse coral reef fishes that show multiple independent evolutionary origins of zooplanktivory. Using phylogenetic comparative methods with a data set from 21 species, we failed to find larger eyes in three independent transitions to zooplanktivory. Instead, an impression of large eyes may be caused by a size reduction of the anterior facial region. However, two zooplanktivores (Clepticus parrae and Halichoeres pictus) possess several features interpreted as adaptations to zooplankton feeding, namely large lens diameters relative to eye axial length, round pupil shape, and long gill rakers. The third zooplanktivore in our analysis, Cirrhilabrus solorensis, lacks all above features. It remains unclear whether Cirrhilabrus shows optical specializations for capturing planktonic prey. Our results support the prediction that increased visual acuity is adaptive for zooplanktivory, but in labrids increases in eye size are apparently not part of the evolutionary response.
-
Ecomorphology of centrarchid fishes
2009Co-Authors: David C Collar, Peter C WainwrightAbstract:From the ecologist’s perspective, centrarchid fishes are widely recognized as a model system for investigating the role of phenotypic variation in shaping ecological patterns. To the ichthyologist, this group is considered among the most morphologically and ecologically diverse of North America’s freshwater ichthyofauna. This chapter is intended to bring these perspectives together, highlighting the contributions of studies linking resource use patterns to morphology in order to make sense of the ecological, functional, and morphological diversity exhibited within the Centrarchidae. We review literature on feeding and on locomotion. Historically, the diversity represented within this radiation helped inspire the development of Ecomorphology, a research perspective that investigates hypothesized associations between organismal design and ecology. Working independently, Werner (1974, 1977) and Keast (1978, 1985; Keast and Webb 1967) were among the first to point out a general association between head and body form and resource use in centrarchid species. Using bluegill sunfish (Lepomis macrochirus), green sunfish (Lepomis cyanellus), and largemouth bass (Micropterus salmoides) to represent the range of ecological and morphological diversity in centrarchids, Werner and coworkers developed the first mechanistic insights into the implications of variation in body and head morphology. The diversity of form and feeding habits represented by bluegill, largemouth bass, black crappie (Pomoxis nigromaculatus), and rock bass (Ambloplites rupestris) motivated Keast’s proposal that different suites of morphological features confer varying prey capture and habitat use capabilities on these species and that these differences underlie the capacity for these species to coexist in sympatry. The rationale for Ecomorphology research can be seen in both Werner’s and Keast’s work: an organism’s morphology affects its capacity to perform an ecologically relevant task, and this performance capacity affects the resources available for its use. This research program was made more explicit (Werner 1977; Mittelbach 1984; Wainwright 1996) by emphasizing that researchers’ ability to explain ecological phenomena through organismal design requires focus on characters whose performance consequences are predictable. This stipulation established a primary role for functional morphology research, which investigates the morphological basis of performance variation. Moreover, the Ecomorphology research perspective led to widespread recognition that the choice of an appropriate performance measure is vital to the success of studies that seek to understand the relationship between morphology and resource use. Performance variables range from proximate measures that focus on the mechanical capacities of isolated functional units, such as maximum pharyngeal jaw bite force, to more integrative measures that involve multiple functional units, like prey handling time, which is influenced by the fish’s ability to capture and process prey. In either case, the performance measure should have predictable consequences for resource use. This is not a trivial issue, as the link between any given performance measure and resource use is more frequently assumed than demonstrated. Nevertheless, studies involving centrarchid fishes provide some of the best examples of the Ecomorphology research program carried out to completion. The morphological diversity of centrarchid fishes ranges between the forms exhibited by the predominant ecomorphs: piscivore/crayfish predator, zooplanktivore, molluscivore, and insectivore, which possess combinations of head and body characters that are associated with different patterns of resource use. Although these ecomorphs are named according to trophic habits, they are generally associated with habitat use patterns as well. Here, we highlight a set of morphological characters that have well-known consequences for performance and resource use. We focus on mouth gape, degree
-
Ecomorphology of locomotion in labrid fishes
Environmental Biology of Fishes, 2002Co-Authors: Peter C Wainwright, David R Bellwood, Mark W WestneatAbstract:The Labridae is an ecologically diverse group of mostly reef associated marine fishes that swim primarily by oscillating their pectoral fins. To generate locomotor thrust, labrids employ the paired pectoral fins in motions that range from a fore-aft rowing stroke to a dorso-ventral flapping stroke. Species that emphasize one or the other behavior are expected to benefit from alternative fin shapes that maximize performance of their primary swimming behavior. We document the diversity of pectoral fin shape in 143 species of labrids from the Great Barrier Reef and the Caribbean. Pectoral fin aspect ratio ranged among species from 1.12 to 4.48 and showed a distribution with two peaks at about 2.0 and 3.0. Higher aspect ratio fins typically had a relatively long leading edge and were narrower distally. Body mass only explained 3% of the variation in fin aspect ratio in spite of four orders of magnitude range and an expectation that the advantages of high aspect ratio fins and flapping motion are greatest at large body sizes. Aspect ratio was correlated with the angle of attachment of the fin on the body (r = 0.65), indicating that the orientation of the pectoral girdle is rotated in high aspect ratio species to enable them to move their fin in a flapping motion. Field measures of routine swimming speed were made in 43 species from the Great Barrier Reef. Multiple regression revealed that fin aspect ratio explained 52% of the variation in size-corrected swimming speed, but the angle of attachment of the pectoral fin only explained an additional 2%. Labrid locomotor diversity appears to be related to a trade-off between efficiency of fast swimming and maneuverability in slow swimming species. Slow swimmers typically swim closer to the reef while fast swimmers dominate the water column and shallow, high-flow habitats. Planktivory was the most common trophic associate with high aspect ratio fins and fast swimming, apparently evolving six times.
-
Ecomorphology of feeding in coral reef fishes
Coral Reef Fishes#R##N#Dynamics and Diversity in a Complex Ecosystem, 2002Co-Authors: Peter C Wainwright, David R BellwoodAbstract:[Extract] O nce an observer gets past the stunning coloration, surely no feature inspires wonder in coral reef fishes so much as their morphological diversity. From large-mouthed groupers, to beaked parrotfish, barbeled goatfish, long-snouted trumpet fish, snaggle-toothed tusk fish, tube-mouthed planktivores, and fat-lipped sweet lips, coral reef fishes display a dazzling array of feeding structures. And, even the most casual fish watcher quickly gets a sense that this diversity means something, that fish form is related to what the animals eat. Clearly there is something to this impression, but just how are head and body morphology connected to prey choice? Are we really able to predict what a reef fish eats from studying its jaws and teeth? What are the major axes of diversification that are seen in reef fishes? Which morphological and ecological trophic types show the most common convergence? What ecological insights into reef processes have been gained from consideration of the functional design of fish feeding mechanisms? In this chapter we explore the relationship between fish anatomy and feeding habits. Our overall goal is to show how an understanding of the functional morphology of fish feeding mechanisms can be a powerful tool when considering several ecological issues in coral reef fish biology. We have attempted to identify generalities, the major patterns that seem to cut across phylogenetic and geographic boundaries. We begin by constructing a rationale for how functional morphology can be used to enhance our insight into some long-standing ecological questions. We then review the fundamental mechanical issues associated with feeding in fishes, and the basic design features of the head that are involved in prey capture and prey processing. This sets the stage for a discussion of how the mechanical properties of fish feeding systems have been modified during reef fish diversification. With this background, we consider some of the major conclusions that have been drawn from studies of reef fish feeding Ecomorphology. Because of space constraints we discuss only briefly the role of sensory modalities--vision, olfaction, electroreception, and hearingmbut these are also significant and diverse elements of the feeding arsenal of coral reef fishes and entire review chapters could be written on each one.
-
Ecomorphology experimental functional anatomy for ecological problems
Integrative and Comparative Biology, 1991Co-Authors: Peter C WainwrightAbstract:It is generally believed that the functional design of an organism relates to its ecology, yet this ecomorphological paradigm has historically suffered from the lack of a rigorous framework for its implementation. I present a methodology for experimentally exploring the ecological consequences of variation in morphology. The central idea is that morphology influences ecology by limiting the ability of the individual to perform key tasks in its daily life. Inthis scheme the effect of morphological variation on behavioral performance is first tested in laboratory experiments. As the behavioral capability of an individual defines the range of ecological resources that it can potentially make use of (the potential niche), the second step in the scheme involves comparing the potential niche of an individual to actual patterns of resource use (the realized niche). This permits a quantitative assessment of the significance of an organism's maximal capabilities in determining actual patterns of resource use. An example is presented from work on the feeding biology of fishes in the family Labridae (wrasses and parrotfishes). Most labrids feed by crushing shelled prey in their powerful pharyngeal jaws. This example explores the dietary consequences of variation in crushing strength amongand within species. Crushing strength was estimated from biomechanical analyses of the crushingapparatus in several species, and these predictions of relative strength were tested in laboratory feeding experiments with hard-shelled prey. Morphology accurately predicted relative crushing ability, and the final section of the study explored the effect of variation in crushing ability on diet. Within each of three species crushing strength appears to underlie a major ontogentic dietary switch from soft-bodied prey to a diet dominated by hard-shelled prey. In each species this switch occurred at about the same crushing strength, around 5 Newtons (N), in spite of the fact that this crushing strength is achieved by the three species at different body sizes. Diet breadth increases during ontogeny in each species, until a crushing strength of 5 N is achieved, when diet breadth begins to decline. The strongest fishes specialized almost entirely on molluscs and sea urchins. Thus, these labrids take advantage of ontogenetic and interspecific differences in crushing strength by including harder and harder prey in their diet, and ultimately specializing on hard prey types. The specialized organization of the labrid pharyngeal jaws can be viewed as a key innovation that has permitted this lineage of fishes to invade the mollusc eating niche, a relatively empty trophic niche within the highly speciose and diverse communities of coral reef fishes.
David R Bellwood - One of the best experts on this subject based on the ideXlab platform.
-
Trophic Ecomorphology of cardinalfish
Marine Ecology Progress Series, 2006Co-Authors: Adam Barnett, David R Bellwood, Andrew S. HoeyAbstract:Trophic diversity in 9 cardinalfish species was investigated by comparing 14 morphological characteristics of their feeding apparatus with dietary data based on stomach content analysis. Analysis of the morphological characteristics separated the 9 species into 3 distinct groups. The first group (Cheilodipterus macrodon, C. artus and C. quinquelineatus) was characterized by elongated heads; the second group (Archamia fucata, Apogon guamensis, A. cyanosoma and A. fragilis) by large gapes; and the third group (Apogon exostigma, A. doederleini) by wider heads and low transmission coefficient in their jaw mechanics. Stomach samples, however, revealed that morphology was of limited utility in predicting dietary groupings. The majority of species examined displayed generalist diets. The results indicate that while morphology may predict feeding potential, or feeding mode, actual resource use in this group may be shaped primarily by other modifying factors such as behaviour and prey availability. In contrast to other reef fish groups, morphology does not appear to play a strong role in influencing diet in the Apogonidae.
-
Ecomorphology of locomotion in labrid fishes
Environmental Biology of Fishes, 2002Co-Authors: Peter C Wainwright, David R Bellwood, Mark W WestneatAbstract:The Labridae is an ecologically diverse group of mostly reef associated marine fishes that swim primarily by oscillating their pectoral fins. To generate locomotor thrust, labrids employ the paired pectoral fins in motions that range from a fore-aft rowing stroke to a dorso-ventral flapping stroke. Species that emphasize one or the other behavior are expected to benefit from alternative fin shapes that maximize performance of their primary swimming behavior. We document the diversity of pectoral fin shape in 143 species of labrids from the Great Barrier Reef and the Caribbean. Pectoral fin aspect ratio ranged among species from 1.12 to 4.48 and showed a distribution with two peaks at about 2.0 and 3.0. Higher aspect ratio fins typically had a relatively long leading edge and were narrower distally. Body mass only explained 3% of the variation in fin aspect ratio in spite of four orders of magnitude range and an expectation that the advantages of high aspect ratio fins and flapping motion are greatest at large body sizes. Aspect ratio was correlated with the angle of attachment of the fin on the body (r = 0.65), indicating that the orientation of the pectoral girdle is rotated in high aspect ratio species to enable them to move their fin in a flapping motion. Field measures of routine swimming speed were made in 43 species from the Great Barrier Reef. Multiple regression revealed that fin aspect ratio explained 52% of the variation in size-corrected swimming speed, but the angle of attachment of the pectoral fin only explained an additional 2%. Labrid locomotor diversity appears to be related to a trade-off between efficiency of fast swimming and maneuverability in slow swimming species. Slow swimmers typically swim closer to the reef while fast swimmers dominate the water column and shallow, high-flow habitats. Planktivory was the most common trophic associate with high aspect ratio fins and fast swimming, apparently evolving six times.
-
evolutionary history of the parrotfishes biogeography Ecomorphology and comparative diversity
Evolution, 2002Co-Authors: J T Streelman, David R Bellwood, Mark W Westneat, Michael E Alfaro, Stephen A KarlAbstract:The family Scaridae comprises about 90 species of herbivorous coral reef, rock reef, and seagrass fishes. Parrotfishes are important agents of marine bioerosion who rework the substrate with their beaklike oral jaws. Many scarid populations are characterized by complex social systems including highly differentiated sexual stages, terri-toriality, and the defense of harems. Here, we test a hypothesis of relationships among parrotfish genera derived from nearly 2 kb of nuclear and mitochondrial DNA sequence. The DNA tree is different than a phylogeny based on comparative morphology and leads to important reinterpretations of scarid evolution. The molecular data suggest a split among seagrass and coral reef associated genera with nearly 80% of all species in the coral reef clade. Our phylogenetic results imply an East Tethyan origin of the family and the recurrent evolution of excavating and scraping feeding modes. It is likely that ecomorphological differences played a significant role in the initial divergence of major scarid lineages, but that variation in color and breeding behavior has triggered subsequent diversification. We present a two-phase model of parrotfish evolution to explain patterns of comparative diversity. Finally, we discuss the application of this model to other adaptively radiating clades.
-
Ecomorphology of feeding in coral reef fishes
Coral Reef Fishes#R##N#Dynamics and Diversity in a Complex Ecosystem, 2002Co-Authors: Peter C Wainwright, David R BellwoodAbstract:[Extract] O nce an observer gets past the stunning coloration, surely no feature inspires wonder in coral reef fishes so much as their morphological diversity. From large-mouthed groupers, to beaked parrotfish, barbeled goatfish, long-snouted trumpet fish, snaggle-toothed tusk fish, tube-mouthed planktivores, and fat-lipped sweet lips, coral reef fishes display a dazzling array of feeding structures. And, even the most casual fish watcher quickly gets a sense that this diversity means something, that fish form is related to what the animals eat. Clearly there is something to this impression, but just how are head and body morphology connected to prey choice? Are we really able to predict what a reef fish eats from studying its jaws and teeth? What are the major axes of diversification that are seen in reef fishes? Which morphological and ecological trophic types show the most common convergence? What ecological insights into reef processes have been gained from consideration of the functional design of fish feeding mechanisms? In this chapter we explore the relationship between fish anatomy and feeding habits. Our overall goal is to show how an understanding of the functional morphology of fish feeding mechanisms can be a powerful tool when considering several ecological issues in coral reef fish biology. We have attempted to identify generalities, the major patterns that seem to cut across phylogenetic and geographic boundaries. We begin by constructing a rationale for how functional morphology can be used to enhance our insight into some long-standing ecological questions. We then review the fundamental mechanical issues associated with feeding in fishes, and the basic design features of the head that are involved in prey capture and prey processing. This sets the stage for a discussion of how the mechanical properties of fish feeding systems have been modified during reef fish diversification. With this background, we consider some of the major conclusions that have been drawn from studies of reef fish feeding Ecomorphology. Because of space constraints we discuss only briefly the role of sensory modalities--vision, olfaction, electroreception, and hearingmbut these are also significant and diverse elements of the feeding arsenal of coral reef fishes and entire review chapters could be written on each one.
Masaya Iijima - One of the best experts on this subject based on the ideXlab platform.
-
Assessment of trophic Ecomorphology in non-alligatoroid crocodylians and its adaptive and taxonomic implications.
Journal of anatomy, 2017Co-Authors: Masaya IijimaAbstract:Although the establishment of trophic Ecomorphology in living crocodylians can contribute to estimating feeding habits of extinct large aquatic reptiles, assessment of ecomorphological traits other than the snout shape has scarcely been conducted in crocodylians. Here, I tested the validity of the proposed trophic ecomorphological traits in crocodylians by examining the correlation between those traits and the snout shape (an established trophic Ecomorphology), using 10 non-alligatoroid crocodylian species with a wide range of snout shape. I then compared the ontogenetic scaling of trophic Ecomorphology to discuss its adaptive and taxonomic significance. The results demonstrated that degree of heterodonty, tooth spacing, size of supratemporal fenestra (STF), ventral extension of pterygoid flange and length of lower jaw symphysis are significantly correlated with snout shape by both non-phylogenetic and phylogenetic regression analyses. Gavialis gangeticus falls outside of 95% prediction intervals for the relationships of some traits and the snout shape, suggesting that piscivorous specialization involves the deviation from the typical transformation axis of skull characters. The comparative snout shape ontogeny revealed a universal trend of snout widening through growth in the sampled crocodylians, implying the existence of a shared size-dependent biomechanical constraint in non-alligatoroid crocodylians. Growth patterns of other traits indicated that G. gangeticus shows atypical trends for degree of heterodonty, size of STF, and symphysis length, whereas the same trends are shared for tooth spacing and ventral extension of pterygoid flange among non-alligatoroid crocodylians. These suggest that some characters are ontogenetically labile in response to prey preference shifts through growth, but other characters are in keeping with the conserved biomechanics among non-alligatoroid crocodylians. Some important taxonomic characters such as the occlusal pattern are likely correlated with ontogeny and trophic Ecomorphology rather than are constrained by phylogenetic relationships, and careful reassessment of such characters might be necessary for better reconstructing the morphological phylogeny of crocodylians.
