1
|
Ingle DN, Perez E, Porter ME, Marshall CD. Feeding without teeth: the material properties of rhamphothecae from two species of durophagous sea turtles. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221424. [PMID: 37090964 PMCID: PMC10113817 DOI: 10.1098/rsos.221424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/27/2023] [Indexed: 05/03/2023]
Abstract
The feeding apparatus of sea turtles comprises cornified keratinous rhamphothecae overlaying a bony rostrum. Although keratin is less stiff than the enamel of toothed animals, certain species of sea turtles are capable of withstanding large forces when feeding on hard prey. We aimed to quantify the mineral density, water content and compressive mechanical properties of rhamphothecae from two durophagous species: loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) sea turtles. Since loggerheads theoretically produce the greater bite forces of these two species, we predicted that keratin from their rhamphothecae would have a greater mineral density and be stiffer, stronger and tougher compared with Kemp's ridley sea turtles. We found that total water weight of hydrated specimens (20%) was consistent between species. Rhamphotheca mineral density ranged between 0 and 0.069 g cm-3; loggerheads had significantly greater mineral density compared with Kemp's ridleys, for which several specimens had no mineral detected. Despite the greater mineral density in loggerheads, we found no significant difference in Young's modulus, yield strength or toughness between these species. In addition to mineral density, our findings suggest that other material components, such as sulfur, may be influencing the material properties of keratin from sea turtle rhamphothecae.
Collapse
Affiliation(s)
- Danielle N. Ingle
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77554, USA
- Gulf Center for Sea Turtle Research, Texas A&M University, College Station, TX 77843, USA
| | - Eliza Perez
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77554, USA
| | - Marianne E. Porter
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Christopher D. Marshall
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77554, USA
- Gulf Center for Sea Turtle Research, Texas A&M University, College Station, TX 77843, USA
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX 77843, USA
| |
Collapse
|
2
|
Püffel F, Johnston R, Labonte D. A biomechanical model for the relation between bite force and mandibular opening angle in arthropods. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221066. [PMID: 36816849 PMCID: PMC9929505 DOI: 10.1098/rsos.221066] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 01/18/2023] [Indexed: 06/18/2023]
Abstract
Bite forces play a key role in animal ecology: they affect mating behaviour, fighting success, and the ability to feed. Although feeding habits of arthropods have a significant ecological and economical impact, we lack fundamental knowledge on how the morphology and physiology of their bite apparatus controls bite performance, and its variation with mandible gape. To address this gap, we derived a biomechanical model that characterizes the relationship between bite force and mandibular opening angle from first principles. We validate this model by comparing its geometric predictions with morphological measurements on the muscoloskeletal bite apparatus of Atta cephalotes leaf-cutter ants, using computed tomography (CT) scans obtained at different mandible opening angles. We then demonstrate its deductive and inductive utility with three examplary use cases: Firstly, we extract the physiological properties of the leaf-cutter ant mandible closer muscle from in vivo bite force measurements. Secondly, we show that leaf-cutter ants are specialized to generate extraordinarily large bite forces, equivalent to about 2600 times their body weight. Thirdly, we discuss the relative importance of morphology and physiology in determining the magnitude and variation of bite force. We hope that a more detailed quantitative understanding of the link between morphology, physiology, and bite performance will facilitate future comparative studies on the insect bite apparatus, and help to advance our knowledge of the behaviour, ecology and evolution of arthropods.
Collapse
Affiliation(s)
- Frederik Püffel
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| | - Richard Johnston
- School of Engineering, Materials Research Centre, Swansea University, Swansea SA2 8PP, UK
| | - David Labonte
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
3
|
Deeming DC. Inter‐relationships among body mass, body dimensions, jaw musculature and bite force in reptiles. J Zool (1987) 2022. [DOI: 10.1111/jzo.12981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- D. C. Deeming
- Joseph Banks Laboratories Department of Life Sciences School of Life and Environmental Sciences University of Lincoln Lincoln UK
| |
Collapse
|
4
|
Isip JE, Jones MEH, Cooper N. Clade-wide variation in bite-force performance is determined primarily by size, not ecology. Proc Biol Sci 2022; 289:20212493. [PMID: 35193399 PMCID: PMC8864353 DOI: 10.1098/rspb.2021.2493] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Performance traits are tightly linked to the fitness of organisms. However, because studies of variation in performance traits generally focus on just one or several closely related species, we are unable to draw broader conclusions about how and why these traits vary across clades. One important performance trait related to many aspects of an animal's life history is bite-force. Here, we use a clade-wide phylogenetic comparative approach to investigate relationships between size, head dimensions and bite-force among lizards and tuatara (lepidosaurs), using the largest bite-force dataset collated to date for any taxonomic group. We test four predictions: that bite-force will be greater in larger species, and for a given body size, bite-force will be greatest in species with acrodont tooth attachment, herbivorous diets, and non-burrowing habits. We show that bite-force is strongly related to body and head size across lepidosaurs and, as predicted, larger species have the greatest bite-forces. Contrary to our other predictions, tooth attachment, diet and habit have little predictive power when accounting for size. Herbivores bite more forcefully simply because they are larger. Our results also highlight priorities for future sampling to further enhance our understanding of broader evolutionary patterns.
Collapse
Affiliation(s)
- Justin E. Isip
- Department of Life Sciences, Natural History Museum London, Cromwell Road, London SW7 5BD, UK,Department of Life Sciences (Silwood Park), Imperial College London, Ascot, UK
| | - Marc E. H. Jones
- Research Department of Cell and Developmental Biology, Anatomy Building, University College London, Gower Street, London WCIE 6BT, UK,Department of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Natalie Cooper
- Department of Life Sciences, Natural History Museum London, Cromwell Road, London SW7 5BD, UK
| |
Collapse
|
5
|
Krings W, Neumann C, Neiber MT, Kovalev A, Gorb SN. Radular force performance of stylommatophoran gastropods (Mollusca) with distinct body masses. Sci Rep 2021; 11:10560. [PMID: 34006949 PMCID: PMC8131350 DOI: 10.1038/s41598-021-89892-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/04/2021] [Indexed: 01/06/2023] Open
Abstract
The forces exerted by the animal's food processing structures can be important parameters when studying trophic specializations to specific food spectra. Even though molluscs represent the second largest animal phylum, exhibiting an incredible biodiversity accompanied by the establishment of distinct ecological niches including the foraging on a variety of ingesta types, only few studies focused on the biomechanical performance of their feeding organs. To lay a keystone for future research in this direction, we investigated the in vivo forces exerted by the molluscan food gathering and processing structure, the radula, for five stylommatophoran species (Gastropoda). The chosen species and individuals have a similar radular morphology and motion, but as they represent different body mass classes, we were enabled to relate the forces to body mass. Radular forces were measured along two axes using force transducers which allowed us to correlate forces with the distinct phases of radular motion. A radular force quotient, AFQ = mean Absolute Force/bodymass0.67, of 4.3 could be determined which can be used further for the prediction of forces generated in Gastropoda. Additionally, some specimens were dissected and the radular musculature mass as well as the radular mass and dimensions were documented. Our results depict the positive correlation between body mass, radular musculature mass, and exerted force. Additionally, it was clearly observed that the radular motion phases, exerting the highest forces during feeding, changed with regard to the ingesta size: all smaller gastropods rather approached the food by a horizontal, sawing-like radular motion leading to the consumption of rather small food particles, whereas larger gastropods rather pulled the ingesta in vertical direction by radula and jaw resulting in the tearing of larger pieces.
Collapse
Affiliation(s)
- Wencke Krings
- Department of Mammalogy and Palaeoanthropology, Center of Natural History (CeNak), Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany. .,Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 9, 24118, Kiel, Germany.
| | - Charlotte Neumann
- Department of Mammalogy and Palaeoanthropology, Center of Natural History (CeNak), Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
| | - Marco T Neiber
- Department of Animal Diversity, Center of Natural History (CeNak), Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany
| | - Alexander Kovalev
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 9, 24118, Kiel, Germany
| | - Stanislav N Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 9, 24118, Kiel, Germany
| |
Collapse
|
6
|
Omeyer LCM, Stokes KL, Beton D, Çiçek BA, Davey S, Fuller WJ, Godley BJ, Sherley RB, Snape RTE, Broderick AC. Investigating differences in population recovery rates of two sympatrically nesting sea turtle species. Anim Conserv 2021. [DOI: 10.1111/acv.12689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- L. C. M. Omeyer
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
| | - K. L. Stokes
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
- Department of Biosciences Swansea University Singleton Park Swansea UK
| | - D. Beton
- Society for the Protection of Turtles Gönyeli North Cyprus
| | - B. A. Çiçek
- Faculty of Arts and Sciences Eastern Mediterranean University Famagusta North Cyprus
| | - S. Davey
- Society for the Protection of Turtles Gönyeli North Cyprus
| | - W. J. Fuller
- Society for the Protection of Turtles Gönyeli North Cyprus
- Faculty of Veterinary Medicine Near East University Nicosia North Cyprus
| | - B. J. Godley
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
| | - R. B. Sherley
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
| | - R. T. E. Snape
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
- Society for the Protection of Turtles Gönyeli North Cyprus
| | - A. C. Broderick
- Centre for Ecology and Conservation College of Life and Environmental Sciences University of Exeter Penryn UK
| |
Collapse
|
7
|
Shi B, Wang Y, Gong L, Chang Y, Liu T, Zhao X, Lin A, Feng J, Jiang T. Correlation of skull morphology and bite force in a bird-eating bat ( Ia io; Vespertilionidae). Front Zool 2020; 17:8. [PMID: 32206076 PMCID: PMC7082990 DOI: 10.1186/s12983-020-00354-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/11/2020] [Indexed: 04/05/2023] Open
Abstract
Background Genetic and ecological factors influence morphology, and morphology is compatible with function. The morphology and bite performance of skulls of bats show a number of characteristic feeding adaptations. The great evening bat, Ia io (Thomas, 1902), eats both insects and birds (Thabah et al. J Mammal 88: 728-735, 2007), and as such, it is considered to represent a case of dietary niche expansion from insects to birds. How the skull morphology or bite force in I. io are related to the expanded diet (that is, birds) remains unknown. We used three-dimensional (3D) geometry of the skulls and measurements of bite force and diets from I. io and 13 other species of sympatric or closely related bat species to investigate the characteristics and the correlation of skull morphology and bite force to diets. Results Significant differences in skull morphology and bite force among species and diets were observed in this study. Similar to the carnivorous bats, bird-eaters (I. io) differed significantly from insectivorous bats; I. io had a larger skull size, taller crania, wider zygomatic arches, shorter but robust mandibles, and larger bite force than the insectivores. The skull morphology of bats was significantly associated with bite force whether controlling for phylogeny or not, but no significant correlations were found between diets and the skulls, or between diets and residual bite force, after controlling for phylogeny. Conclusions These results indicated that skull morphology was independent of diet, and phylogeny had a greater impact on skull morphology than diet in these species. The changes in skull size and morphology have led to variation in bite force, and finally different bat species feeding on different foods. In conclusion, I. io has a larger skull size, robust mandibles, shortened dentitions, longer coronoid processes, expanded angular processes, low condyles, and taller cranial sagittal crests, and wider zygomatic arches that provide this species with mechanical advantages; their greater bite force may help them use larger and hard-bodied birds as a dietary component.
Collapse
Affiliation(s)
- Biye Shi
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Yuze Wang
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Lixin Gong
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Yang Chang
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Tong Liu
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Xin Zhao
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Aiqing Lin
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| | - Jiang Feng
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,3College of Life Science, Jilin Agricultural University, 2888 Xincheng Street, Changchun, 130118 China
| | - Tinglei Jiang
- 1Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China.,2Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, 2555 Jingyue Street, Changchun, 130117 China
| |
Collapse
|
8
|
Warraich N, Wyneken J, Blume N. Feeding behavior and visual field differences in loggerhead and leatherback sea turtles may explain differences in longline fisheries interactions. ENDANGER SPECIES RES 2020. [DOI: 10.3354/esr01012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
9
|
Hite NJ, Germain C, Cain BW, Sheldon M, Perala SSN, Sarko DK. The Better to Eat You With: Bite Force in the Naked Mole-Rat ( Heterocephalus glaber) Is Stronger Than Predicted Based on Body Size. Front Integr Neurosci 2019; 13:70. [PMID: 31866840 PMCID: PMC6904307 DOI: 10.3389/fnint.2019.00070] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 11/19/2019] [Indexed: 12/30/2022] Open
Abstract
Naked mole-rats (Heterocephalus glaber) are subterranean rodents that utilize their incisors for feeding, chisel-tooth digging of complex tunnel systems, social interactions, and defense in their eusocial colony structure. Previous studies have shown that naked mole-rats have morphological and anatomical adaptations that predict strong bite forces, namely, skulls that are relatively tall and wide, in addition to impressive masticatory musculature. However, no studies to date have directly measured bite force in this species or analyzed the relationship between bite force and social caste. In the current study, we assessed adult naked mole-rat maximum bite force in relation to body mass, in addition to considering each animal's position within the eusocial hierarchy (i.e., dominant versus subordinate). Each animal was permitted to freely interact with a piezo-resistive bite force sensor. Our results showed that bite force was correlated with body mass in subordinate but not in dominant naked mole-rats, and that subordinate animals exhibited a shorter latency in producing their first bite. Maximum bite force was significantly influenced by caste. In comparing bite force with available data from previous studies across 82 additional mammalian species, subordinate naked mole-rats exhibited a bite force that was 65% higher than predicted for their body size, comparable to Tasmanian devils and exceeding bite force values for all of the carnivorans included for comparison. These results supported the hypothesis that the naked mole-rat's bite force would exceed predictions based on body size due to the behavioral importance and specialization of the naked mole-rat incisors. This study provides insight into the differences in bite force across species, and the significant role that social and ecological factors might play in the evolutionary relationship between bite force performance and underlying anatomical structures.
Collapse
Affiliation(s)
- Natalee J. Hite
- Department of Physiology, School of Medicine, Southern Illinois University, Carbondale, IL, United States
| | - Cody Germain
- Southern Illinois University, Carbondale, IL, United States
| | - Blake W. Cain
- School of Medicine, Southern Illinois University, Carbondale, IL, United States
| | - Mason Sheldon
- Southern Illinois University, Carbondale, IL, United States
| | - Sai Saketh Nandan Perala
- Department of Electrical and Computer Engineering, Southern Illinois University, Carbondale, IL, United States
| | - Diana K. Sarko
- Department of Anatomy, School of Medicine, Southern Illinois University, Carbondale, IL, United States
| |
Collapse
|
10
|
O'Rourke DP, Baccanale CL, Stoskopf MK. Nontraditional Laboratory Animal Species (Cephalopods, Fish, Amphibians, Reptiles, and Birds). ILAR J 2019; 59:168-176. [PMID: 30462255 DOI: 10.1093/ilar/ily003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 04/18/2018] [Indexed: 12/27/2022] Open
Abstract
Aquatic vertebrates and cephalopods, amphibians, reptiles, and birds offer unique safety and occupational health challenges for laboratory animal personnel. This paper discusses environmental, handling, and zoonotic concerns associated with these species.
Collapse
Affiliation(s)
- Dorcas P O'Rourke
- Dorcas P. O'Rourke, DVM, MS, DACLAM, is Professor and Chair of the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Cecile L. Baccanale, DVM, is Associate Professor in the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Michael K. Stoskopf, DVM, PhD, DACZM, is Professor in the Department of Clinical Sciences, at the College of Veterinary Medicine as well as the Colleges of Natural Resources, Science, and Engineering at North Carolina State University in Raleigh, North Carolina
| | - Cecile L Baccanale
- Dorcas P. O'Rourke, DVM, MS, DACLAM, is Professor and Chair of the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Cecile L. Baccanale, DVM, is Associate Professor in the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Michael K. Stoskopf, DVM, PhD, DACZM, is Professor in the Department of Clinical Sciences, at the College of Veterinary Medicine as well as the Colleges of Natural Resources, Science, and Engineering at North Carolina State University in Raleigh, North Carolina
| | - Michael K Stoskopf
- Dorcas P. O'Rourke, DVM, MS, DACLAM, is Professor and Chair of the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Cecile L. Baccanale, DVM, is Associate Professor in the Department of Comparative Medicine at the Brody School of Medicine, East Carolina University in Greenville, North Carolina. Michael K. Stoskopf, DVM, PhD, DACZM, is Professor in the Department of Clinical Sciences, at the College of Veterinary Medicine as well as the Colleges of Natural Resources, Science, and Engineering at North Carolina State University in Raleigh, North Carolina
| |
Collapse
|
11
|
Higgins BA, Law CJ, Mehta RS. Eat whole and less often: ontogenetic shift reveals size specialization on kelp bass by the California moray eel, Gymnothorax mordax. Oecologia 2018; 188:875-887. [PMID: 30229354 PMCID: PMC6208710 DOI: 10.1007/s00442-018-4260-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Accepted: 09/08/2018] [Indexed: 11/29/2022]
Abstract
Despite the importance of predation in many ecosystems, gaps remain in our understanding of nocturnal marine predators. Although the kelp forests of Southern California are some of the most well-studied ecosystems, California morays, Gymnothorax mordax, are predominately nocturnal predators that have remained largely unstudied and their predatory effects on the kelp forest ecosystem are unknown. We use a multi-year data set to examine the dietary breadth of G. mordax and to determine the functional role of this predator. We also quantify bite force to examine the potential performance limitations of morays in exploiting prey. Stomach content analyses and linear selectivity index values indicate that G. mordax specializes on kelp bass, Paralabrax clathratus. Average size of kelp bass consumed varies across years, suggesting that morays respond to fluctuations in prey size availability. The scaling relationship of kelp bass standard length and moray head length reveals an ontogenetic shift, where maximum prey size increases with moray size and small prey are dropped from the diet of larger individuals. Moray bite force exhibited strong positive allometry with moray head size, suggesting that larger morays exhibit greater bite forces for their head and body size. However, we found no relationship between prey size and bite force, suggesting that a disproportional increase in bite force does not facilitate the consumption of disproportionately larger prey. Our results indicate that while G. mordax of Catalina Island is a dietary specialist, it is capable of exhibiting functional shifts in prey size and species based on their abundance.
Collapse
Affiliation(s)
- Benjamin A Higgins
- Department of Ecology and Evolutionary Biology, Center for Coastal Biology, 130 McAllister Way, Santa Cruz, CA, 95060, USA.
| | - Chris J Law
- Department of Ecology and Evolutionary Biology, Center for Coastal Biology, 130 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Rita S Mehta
- Department of Ecology and Evolutionary Biology, Center for Coastal Biology, 130 McAllister Way, Santa Cruz, CA, 95060, USA
| |
Collapse
|
12
|
De Meyer J, Goethals T, Van Wassenbergh S, Augustijns T, Habraken J, Hellemans J, Vandewiele V, Dhaene J, Bouillart M, Adriaens D. Dimorphism throughout the European eel's life cycle: are ontogenetic changes in head shape related to dietary differences? J Anat 2018; 233:289-301. [PMID: 29855043 PMCID: PMC6081510 DOI: 10.1111/joa.12836] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2018] [Indexed: 01/05/2023] Open
Abstract
A well-known link exists between an organism's ecology and morphology. In the European eel, a dimorphic head has been linked to differences in feeding ecology, with broad-headed eels consuming harder prey items than narrow-headed ones. Consequently, we hypothesized that broad-heads should exhibit a cranial musculoskeletal system that increases bite force and facilitates the consumption of harder prey. Using 3D-reconstructions and a bite model, we tested this hypothesis in two life stages: the sub-adult yellow eel stage and its predecessor, the elver eel stage. This allowed us to test whether broad- and narrow-headed phenotypes show similar trait differences in both life stages and whether the dimorphism becomes more pronounced during ontogeny. We show that broad-headed eels in both stages have larger jaw muscles and a taller coronoid, which are associated with higher bite forces. This increased bite force together with the elongated upper and lower jaws in broad-headed eels can also improve grip during spinning behavior, which is used to manipulate hard prey. Head shape variation in European eel is therefore associated with musculoskeletal variation that can be linked to feeding ecology. However, although differences in muscle volume become more pronounced during ontogeny, this was not the case for skeletal features.
Collapse
Affiliation(s)
- J. De Meyer
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - T. Goethals
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - S. Van Wassenbergh
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
- Département Adaptations du VivantUMR 7179 C.N.R.S/M.N.H.N.Paris Cedex 05France
| | - T. Augustijns
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - J. Habraken
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - J. Hellemans
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - V. Vandewiele
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - J. Dhaene
- Department of Physics and AstronomyUGCT – Radiation PhysicsGhent UniversityGhentBelgium
| | - M. Bouillart
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| | - D. Adriaens
- Evolutionary Morphology of VertebratesGhent UniversityGhentBelgium
| |
Collapse
|
13
|
Lappin AK, Wilcox SC, Moriarty DJ, Stoeppler SAR, Evans SE, Jones MEH. Bite force in the horned frog (Ceratophrys cranwelli) with implications for extinct giant frogs. Sci Rep 2017; 7:11963. [PMID: 28931936 PMCID: PMC5607344 DOI: 10.1038/s41598-017-11968-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 09/01/2017] [Indexed: 12/22/2022] Open
Abstract
Of the nearly 6,800 extant frog species, most have weak jaws that play only a minor role in prey capture. South American horned frogs (Ceratophrys) are a notable exception. Aggressive and able to consume vertebrates their own size, these “hopping heads” use a vice-like grip of their jaws to restrain and immobilize prey. Using a longitudinal experimental design, we quantified the ontogenetic profile of bite-force performance in post-metamorphic Ceratophrys cranwelli. Regression slopes indicate positive allometric scaling of bite force with reference to head and body size, results that concur with scaling patterns across a diversity of taxa, including fish and amniotes (lizards, tuatara, turtles, crocodylians, rodents). Our recovered scaling relationship suggests that exceptionally large individuals of a congener (C. aurita) and extinct giant frogs (Beelzebufo ampinga, Late Cretaceous of Madagascar) probably could bite with forces of 500 to 2200 N, comparable to medium to large-sized mammalian carnivores.
Collapse
Affiliation(s)
- A Kristopher Lappin
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, 91768, USA.
| | - Sean C Wilcox
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, 91768, USA.,Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, 92521, USA
| | - David J Moriarty
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, 91768, USA
| | - Stephanie A R Stoeppler
- Biological Sciences Department, California State Polytechnic University, Pomona, CA, 91768, USA
| | - Susan E Evans
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Marc E H Jones
- School of Biological Sciences, The University of Adelaide, South Australia, 5005, Australia.,South Australian Museum, Adelaide, South Australia, 5000, Australia
| |
Collapse
|
14
|
Price JT, Pfaller JB, Vander Zanden HB, Williams KL, Bolten AB, Bjorndal KA. Foraging area, not trophic position, is linked to head size variation in adult female loggerhead turtles. J Zool (1987) 2017. [DOI: 10.1111/jzo.12456] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. T. Price
- Department of Biology Indiana University‐Purdue University Fort Wayne Fort Wayne IN USA
- Caretta Research Project Savannah GA USA
| | - J. B. Pfaller
- Caretta Research Project Savannah GA USA
- Archie Carr Center for Sea Turtle Research and Department of Biology University of Florida Gainesville FL USA
| | - H. B. Vander Zanden
- Archie Carr Center for Sea Turtle Research and Department of Biology University of Florida Gainesville FL USA
| | | | - A. B. Bolten
- Archie Carr Center for Sea Turtle Research and Department of Biology University of Florida Gainesville FL USA
| | - K. A. Bjorndal
- Archie Carr Center for Sea Turtle Research and Department of Biology University of Florida Gainesville FL USA
| |
Collapse
|
15
|
Casale P, Freggi D, Rigoli A, Ciccocioppo A, Luschi P. Geometric morphometrics, scute patterns and biometrics of loggerhead turtles (Caretta caretta) in the central Mediterranean. AMPHIBIA-REPTILIA 2017. [DOI: 10.1163/15685381-00003096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
We investigate for the first time allometric vs. non-allometric shape variation in sea turtles through a geometric morphometrics approach. Five body parts (carapace, plastron, top and lateral sides of the head, dorsal side of front flippers) were considered in a sample of 58 loggerhead turtles (Caretta caretta) collected in the waters around Lampedusa island, Italy, the central Mediterranean. The allometric component was moderate but significant, except for the plastron, and may represent an ontogenetic optimization in the case of the head and flippers. The predominant non-allometric component encourages further investigation with sex and origin as potential explanatory variables. We also reported the variation of marginal and prefrontal scutes of 1497 turtles, showing that: variation of marginals is mostly limited to the two anteriormost scutes, symmetry is favored, asymmetry is biased to one pattern, and the variation of marginal and prefrontal scutes are linked. Comparisons with other datasets from the Mediterranean show a high variability, more likely caused by epigenetic factors. Finally, conversion equations between the most commonly used biometrics (curved and straight carapace length, carapace width, and weight) are often needed in sea turtle research but are lacking for the Mediterranean and are here estimated from a sample of 2624 turtles.
Collapse
Affiliation(s)
- Paolo Casale
- Department of Biology, University of Pisa, Via A. Volta 6, I-56126, Pisa, Italy
| | | | - Alessandro Rigoli
- Department of Biology, University of Pisa, Via A. Volta 6, I-56126, Pisa, Italy
| | - Amedeo Ciccocioppo
- Department of Biology, University of Pisa, Via A. Volta 6, I-56126, Pisa, Italy
| | - Paolo Luschi
- Department of Biology, University of Pisa, Via A. Volta 6, I-56126, Pisa, Italy
| |
Collapse
|
16
|
Law CJ, Young C, Mehta RS. Ontogenetic Scaling of Theoretical Bite Force in Southern Sea Otters (Enhydra lutris nereis). Physiol Biochem Zool 2016; 89:347-63. [DOI: 10.1086/688313] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
17
|
Santana SE, Miller KE. Extreme Postnatal Scaling in Bat Feeding Performance: A View of Ecomorphology from Ontogenetic and Macroevolutionary Perspectives. Integr Comp Biol 2016; 56:459-68. [DOI: 10.1093/icb/icw075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
|
18
|
McCord CL, Westneat MW. Evolutionary patterns of shape and functional diversification in the skull and jaw musculature of triggerfishes (Teleostei: Balistidae). J Morphol 2016; 277:737-52. [DOI: 10.1002/jmor.20531] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 02/17/2016] [Accepted: 02/21/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Charlene L. McCord
- Department of Organismal Biology and Anatomy; University of Chicago; Chicago, Illinois 60637
- Field Museum of Natural History, Division of Fishes; Chicago Illlinois 60605
| | - Mark W. Westneat
- Department of Organismal Biology and Anatomy; University of Chicago; Chicago, Illinois 60637
- Field Museum of Natural History, Division of Fishes; Chicago Illlinois 60605
| |
Collapse
|
19
|
Holley JAC, Moreau CS, Laird JG, Suarez AV. Subcaste-specific evolution of head size in the ant genusPheidole. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12769] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Jo-Anne C. Holley
- Department of Entomology; University of Illinois; 320 Morrill Hall 505 S. Goodwin Ave Urbana IL 61801 USA
| | - Corrie S. Moreau
- Department of Science and Education; Center for Integrative Research; Field Museum of Natural History; 1400 South Lake Shore Drive Chicago IL 60605 USA
| | - Joseph G. Laird
- Department of Biochemistry; University of Iowa; 4-403 BSB Iowa City IA 52242 USA
| | - Andrew V. Suarez
- Department of Entomology; University of Illinois; 320 Morrill Hall 505 S. Goodwin Ave Urbana IL 61801 USA
- Department of Animal Biology; University of Illinois; 515 Morrill Hall 505 S. Goodwin Ave Urbana IL 61801 USA
| |
Collapse
|
20
|
Inverse Relationship between Biting and Head Retraction in an Ontogenetic Series of Sonoran Mud Turtles ( Kinosternon sonoriense). J HERPETOL 2016. [DOI: 10.1670/14-122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
21
|
Dumont M, Wall CE, Botton-Divet L, Goswami A, Peigné S, Fabre AC. Do functional demands associated with locomotor habitat, diet, and activity pattern drive skull shape evolution in musteloid carnivorans? Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12719] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Maïtena Dumont
- UMR CNRS/MNHN 7179; “Mécanismes adaptatifs: des organismes aux communautés”; 55 Rue Buffon 75005 Paris France
| | - Christine E. Wall
- Evolutionary Anthropology; Duke University; Durham NC 27708-0383 USA
| | - Léo Botton-Divet
- UMR CNRS/MNHN 7179; “Mécanismes adaptatifs: des organismes aux communautés”; 55 Rue Buffon 75005 Paris France
| | - Anjali Goswami
- Department of Genetics, Evolution, and Environment and Department of Earth Sciences; University College London; Darwin Building 118A Gower Street London WC1E 6BT UK
| | - Stéphane Peigné
- CR2P - UMR 7207 CNRS; MNHN; Univ Paris 06 Paris 75005 France
| | - Anne-Claire Fabre
- Evolutionary Anthropology; Duke University; Durham NC 27708-0383 USA
| |
Collapse
|
22
|
Kane EA, Higham TE. Complex Systems Are More than the Sum of Their Parts: Using Integration to Understand Performance, Biomechanics, and Diversity. Integr Comp Biol 2015; 55:146-65. [DOI: 10.1093/icb/icv033] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
|
23
|
Fukuoka T, Narazaki T, Sato K. Summer-restricted migration of green turtles Chelonia mydas to a temperate habitat of the northwest Pacific Ocean. ENDANGER SPECIES RES 2015. [DOI: 10.3354/esr00671] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
24
|
Marshall CD, Rosen D, Trites AW. Feeding kinematics and performance of basal otariid pinnipeds, Steller sea lions (Eumetopias jubatus), and northern fur seals (Callorhinus ursinus): implications for the evolution of mammalian feeding. J Exp Biol 2015; 218:3229-40. [DOI: 10.1242/jeb.126573] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/18/2015] [Indexed: 12/16/2022]
Abstract
Feeding performance studies can address questions relevant to feeding ecology and evolution. Our current understanding of feeding mechanisms for aquatic mammals is poor. Therefore, we characterized the feeding kinematics and performance of 5 Steller sea lions (Eumetopias jubatus) and 6 northern fur seals (Callorhinus ursinus). We tested the hypotheses that both species use suction as their primary feeding mode, and that rapid jaw opening was related to suction generation. Steller sea lions used suction as their primary feeding mode, but also used a biting feeding mode. In contrast, Northern fur seals only used a biting feeding mode. Kinematic profiles of Steller sea lions were all indicative of suction feeding (i.e., a small gape, small gape angle, large depression of the hyolingual apparatus and lip pursing). However, jaw opening as measured by Gape Angle Opening Velocity (GAOV) was relatively slow in Steller sea lions. In contrast to Steller sea lions, the GAOV of Northern fur seals was extremely fast, but their kinematic profiles indicated a biting feeding mode (i.e., northern fur seals exhibited a greater gape, a greater gape angle, and minimal depression of the hyolingual apparatus compared to Steller sea lions). Steller sea lions produced both subambient and suprambient pressures at 45 kPa, respectively. In contrast, northern fur seals produced no detectable pressure measurements. Steller sea lions have a broader feeding repertoire than northern fur seals, which likely enables them to feed on a greater variety of prey, in more diverse habitats. Based on the basal phylogenetic position of northern fur seals, craniodental morphological data of the Callorhinus lineage, and the performance data provided in this study, we suggest that a northern fur seals may be exhibiting their ancestral feeding mode.
Collapse
Affiliation(s)
- Christopher D. Marshall
- Texas A&M University, Department of Marine Biology, Galveston, TX 77553, USA
- Texas A&M University, Department of Wildlife and Fisheries Sciences, College Station, TX 77840, USA
| | - David Rosen
- Marine Mammal Research Unit,
Fisheries Centre, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Andrew W. Trites
- Marine Mammal Research Unit,
Fisheries Centre, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| |
Collapse
|
25
|
Broeckhoven C, Mouton PLFN. Under pressure: morphological and ecological correlates of bite force in the rock-dwelling lizardsOuroborus cataphractusandKarusasaurus polyzonus(Squamata: Cordylidae). Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12242] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chris Broeckhoven
- Department of Botany & Zoology; Stellenbosch University; Private Bag X1 Matieland 7602 Stellenbosch South Africa
| | - P. le Fras N. Mouton
- Department of Botany & Zoology; Stellenbosch University; Private Bag X1 Matieland 7602 Stellenbosch South Africa
| |
Collapse
|
26
|
Lappin AK, Jones ME. Reliable quantification of bite-force performance requires use of appropriate biting substrate and standardization of bite out-lever. J Exp Biol 2014; 217:4303-12. [DOI: 10.1242/jeb.106385] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Bite-force performance is an ecologically important measure of whole-organism performance that shapes dietary breadth and feeding strategies and, in some taxa, determines reproductive success. It also is a metric critical to testing and evaluating biomechanical models. We reviewed nearly one-hundred published studies of a range of taxa that incorporate direct in vivo measurements of bite force. Problematically, methods of data collection and processing vary considerably among studies. In particular, there is little consensus on the appropriate substrate to use on the biting surface of force transducers. In addition, the bite out-lever, defined as the distance from the fulcrum (i.e. jaw joint) to the position along the jawline at which the jaws engage the transducer, is rarely taken into account. We examined the effect of bite substrate and bite out-lever on bite-force estimates in a diverse sample of lizards. Results indicate that both variables have a significant impact on the accuracy of measurements. Maximum bite force is significantly greater using leather as the biting substrate, as compared to a metal substrate. Less forceful bites on metal are likely due to inhibitory feedback from mechanoreceptors that prevent damage to the feeding apparatus. Standardization of bite out-lever affected which trial produced maximum performance for a given individual. Indeed, maximum bite force usually is underestimated without standardization because it is expected to be greatest at the minimum out-lever (i.e. back of jaws), which in studies is rarely targeted with success. We assert that future studies should use a pliable substrate, such as leather, and employ appropriate standardization for bite out-lever.
Collapse
Affiliation(s)
| | - Marc E.H. Jones
- University of Adelaide, Australia; University College London, UK; South Australian Museum, Australia
| |
Collapse
|
27
|
Welsh JQ, Goatley CHR, Bellwood DR. The ontogeny of home ranges: evidence from coral reef fishes. Proc Biol Sci 2013; 280:20132066. [PMID: 24174108 PMCID: PMC3826221 DOI: 10.1098/rspb.2013.2066] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 10/03/2013] [Indexed: 11/12/2022] Open
Abstract
The concept of home ranges is fundamental to ecology. Numerous studies have quantified how home ranges scale with body size across taxa. However, these relationships are not always applicable intraspecifically. Here, we describe how the home range of an important group of reef fish, the parrotfishes, scales with body mass. With masses spanning five orders of magnitude, from the early postsettlement stage through to adulthood, we find no evidence of a response to predation risk, dietary shifts or sex change on home range expansion rates. Instead, we document a distinct ontogenetic shift in home range expansion with sexual maturity. Juvenile parrotfishes displayed rapid home range growth until reaching approximately 100-150 mm length. Thereafter, the relationship between home range and mass broke down. This shift reflected changes in colour patterns, social status and reproductive behaviour associated with the transition to adult stages. While there is a clear relationship between body mass and home ranges among adult individuals of different species, it does not appear to be applicable to size changes within species. Ontogenetic changes in parrotfishes do not follow expected mass-area scaling relationships.
Collapse
Affiliation(s)
- J. Q. Welsh
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| | - C. H. R. Goatley
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| | - D. R. Bellwood
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
| |
Collapse
|
28
|
Narazaki T, Sato K, Abernathy KJ, Marshall GJ, Miyazaki N. Loggerhead turtles (Caretta caretta) use vision to forage on gelatinous prey in mid-water. PLoS One 2013; 8:e66043. [PMID: 23776603 PMCID: PMC3680403 DOI: 10.1371/journal.pone.0066043] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/03/2013] [Indexed: 12/02/2022] Open
Abstract
Identifying characteristics of foraging activity is fundamental to understanding an animals’ lifestyle and foraging ecology. Despite its importance, monitoring the foraging activities of marine animals is difficult because direct observation is rarely possible. In this study, we use an animal-borne imaging system and three-dimensional data logger simultaneously to observe the foraging behaviour of large juvenile and adult sized loggerhead turtles (Caretta caretta) in their natural environment. Video recordings showed that the turtles foraged on gelatinous prey while swimming in mid-water (i.e., defined as epipelagic water column deeper than 1 m in this study). By linking video and 3D data, we found that mid-water foraging events share the common feature of a marked deceleration phase associated with the capture and handling of the sluggish prey. Analysis of high-resolution 3D movements during mid-water foraging events, including presumptive events extracted from 3D data using deceleration in swim speed as a proxy for foraging (detection rate = 0.67), showed that turtles swam straight toward prey in 171 events (i.e., turning point absent) but made a single turn toward the prey an average of 5.7±6.0 m before reaching the prey in 229 events (i.e., turning point present). Foraging events with a turning point tended to occur during the daytime, suggesting that turtles primarily used visual cues to locate prey. In addition, an incident of a turtle encountering a plastic bag while swimming in mid-water was recorded. The fact that the turtle’s movements while approaching the plastic bag were analogous to those of a true foraging event, having a turning point and deceleration phase, also support the use of vision in mid-water foraging. Our study shows that integrated video and high-resolution 3D data analysis provides unique opportunities to understand foraging behaviours in the context of the sensory ecology involved in prey location.
Collapse
Affiliation(s)
- Tomoko Narazaki
- International Coastal Research Center, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan.
| | | | | | | | | |
Collapse
|
29
|
Jones MEH, Werneburg I, Curtis N, Penrose R, O'Higgins P, Fagan MJ, Evans SE. The head and neck anatomy of sea turtles (Cryptodira: Chelonioidea) and skull shape in Testudines. PLoS One 2012; 7:e47852. [PMID: 23144831 PMCID: PMC3492385 DOI: 10.1371/journal.pone.0047852] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 09/19/2012] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Sea turtles (Chelonoidea) are a charismatic group of marine reptiles that occupy a range of important ecological roles. However, the diversity and evolution of their feeding anatomy remain incompletely known. METHODOLOGY/PRINCIPAL FINDINGS Using computed tomography and classical comparative anatomy we describe the cranial anatomy in two sea turtles, the loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii), for a better understanding of sea turtle functional anatomy and morphological variation. In both taxa the temporal region of the skull is enclosed by bone and the jaw joint structure and muscle arrangement indicate that palinal jaw movement is possible. The tongue is relatively small, and the hyoid apparatus is not as conspicuous as in some freshwater aquatic turtles. We find several similarities between the muscles of C. caretta and L. kempii, but comparison with other turtles suggests only one of these characters may be derived: connection of the m. adductor mandibulae internus into the Pars intramandibularis via the Zwischensehne. The large fleshy origin of the m. adductor mandibulae externus Pars superficialis from the jugal seems to be a characteristic feature of sea turtles. CONCLUSIONS/SIGNIFICANCE In C. caretta and L. kempii the ability to suction feed does not seem to be as well developed as that found in some freshwater aquatic turtles. Instead both have skulls suited to forceful biting. This is consistent with the observation that both taxa tend to feed on relatively slow moving but sometimes armoured prey. The broad fleshy origin of the m. adductor mandibulae externus Pars superficialis may be linked to thecheek region being almost fully enclosed in bone but the relationship is complex.
Collapse
Affiliation(s)
- Marc E H Jones
- Research Department of Cell and Developmental Biology, UCL, University College London, London, England, United Kingdom.
| | | | | | | | | | | | | |
Collapse
|