Internal vertebral morphology of bony fishes matches the mechanical demands of different environments
Abstract Fishes have repeatedly evolved characteristic body shapes depending on how close they live to the substrate. Pelagic fishes live in open water and typically have narrow, streamlined body shapes; benthic and demersal fishes live close to the substrate; and demersal fishes often have deeper b...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2022-11-01
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| Series: | Ecology and Evolution |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/ece3.9499 |
| _version_ | 1811211825962811392 |
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| author | Dana Baxter Karly E. Cohen Cassandra M. Donatelli Eric D. Tytell |
| author_facet | Dana Baxter Karly E. Cohen Cassandra M. Donatelli Eric D. Tytell |
| author_sort | Dana Baxter |
| collection | DOAJ |
| description | Abstract Fishes have repeatedly evolved characteristic body shapes depending on how close they live to the substrate. Pelagic fishes live in open water and typically have narrow, streamlined body shapes; benthic and demersal fishes live close to the substrate; and demersal fishes often have deeper bodies. These shape differences are often associated with behavioral differences: pelagic fishes swim nearly constantly, demersal fishes tend to maneuver near the substrate, and benthic fishes often lie in wait on the substrate. We hypothesized that these morphological and behavioral differences would be reflected in the mechanical properties of the body, and specifically in vertebral column stiffness, because it is an attachment point for the locomotor musculature and a central axis for body bending. The vertebrae of bony fishes are composed of two cones connected by a foramen, which is filled by the notochord. Since the notochord is more flexible than bony vertebral centra, we predicted that pelagic fishes would have narrower foramina or shallower cones, leading to less notochordal material and a stiffer vertebral column which might support continuous swimming. In contrast, we predicted that benthic and demersal fishes would have more notochordal material, making the vertebral column more flexible for diverse behaviors in these species. We therefore examined vertebral morphology in 79 species using micro‐computed tomography scans. Six vertebral features were measured including notochordal foramen diameter, centrum body length, and the cone angles and diameters for the anterior and posterior vertebral cones, along with body fineness. Using phylogenetic generalized least squares analyses, we found that benthic and pelagic species differed significantly, with larger foramina, shorter centra, and larger cones in benthic species. Thus, morphological differences in the internal shape of the vertebrae of fishes are consistent with a stiffer vertebral column in pelagic fishes and with a more flexible vertebral column in benthic species. |
| first_indexed | 2024-04-12T05:19:53Z |
| format | Article |
| id | doaj.art-0b8a2b3ce5964bca9811a846490c2649 |
| institution | Directory Open Access Journal |
| issn | 2045-7758 |
| language | English |
| last_indexed | 2024-04-12T05:19:53Z |
| publishDate | 2022-11-01 |
| publisher | Wiley |
| record_format | Article |
| series | Ecology and Evolution |
| spelling | doaj.art-0b8a2b3ce5964bca9811a846490c26492022-12-22T03:46:30ZengWileyEcology and Evolution2045-77582022-11-011211n/an/a10.1002/ece3.9499Internal vertebral morphology of bony fishes matches the mechanical demands of different environmentsDana Baxter0Karly E. Cohen1Cassandra M. Donatelli2Eric D. Tytell3Department of Biology Tufts University Medford Massachusetts USADepartment of Biology University of Florida Gainesville Florida USAFowler School of Engineering Chapman University Orange California USADepartment of Biology Tufts University Medford Massachusetts USAAbstract Fishes have repeatedly evolved characteristic body shapes depending on how close they live to the substrate. Pelagic fishes live in open water and typically have narrow, streamlined body shapes; benthic and demersal fishes live close to the substrate; and demersal fishes often have deeper bodies. These shape differences are often associated with behavioral differences: pelagic fishes swim nearly constantly, demersal fishes tend to maneuver near the substrate, and benthic fishes often lie in wait on the substrate. We hypothesized that these morphological and behavioral differences would be reflected in the mechanical properties of the body, and specifically in vertebral column stiffness, because it is an attachment point for the locomotor musculature and a central axis for body bending. The vertebrae of bony fishes are composed of two cones connected by a foramen, which is filled by the notochord. Since the notochord is more flexible than bony vertebral centra, we predicted that pelagic fishes would have narrower foramina or shallower cones, leading to less notochordal material and a stiffer vertebral column which might support continuous swimming. In contrast, we predicted that benthic and demersal fishes would have more notochordal material, making the vertebral column more flexible for diverse behaviors in these species. We therefore examined vertebral morphology in 79 species using micro‐computed tomography scans. Six vertebral features were measured including notochordal foramen diameter, centrum body length, and the cone angles and diameters for the anterior and posterior vertebral cones, along with body fineness. Using phylogenetic generalized least squares analyses, we found that benthic and pelagic species differed significantly, with larger foramina, shorter centra, and larger cones in benthic species. Thus, morphological differences in the internal shape of the vertebrae of fishes are consistent with a stiffer vertebral column in pelagic fishes and with a more flexible vertebral column in benthic species.https://doi.org/10.1002/ece3.9499mechanicsstatistical modelingvertebral morphology |
| spellingShingle | Dana Baxter Karly E. Cohen Cassandra M. Donatelli Eric D. Tytell Internal vertebral morphology of bony fishes matches the mechanical demands of different environments Ecology and Evolution mechanics statistical modeling vertebral morphology |
| title | Internal vertebral morphology of bony fishes matches the mechanical demands of different environments |
| title_full | Internal vertebral morphology of bony fishes matches the mechanical demands of different environments |
| title_fullStr | Internal vertebral morphology of bony fishes matches the mechanical demands of different environments |
| title_full_unstemmed | Internal vertebral morphology of bony fishes matches the mechanical demands of different environments |
| title_short | Internal vertebral morphology of bony fishes matches the mechanical demands of different environments |
| title_sort | internal vertebral morphology of bony fishes matches the mechanical demands of different environments |
| topic | mechanics statistical modeling vertebral morphology |
| url | https://doi.org/10.1002/ece3.9499 |
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