TY - JOUR
T1 - Ontogeny of feeding mechanics in smoothhound sharks
T2 - Morphology and cartilage stiffness
AU - Wilga, Cheryl A D
AU - Diniz, Stephanye E.
AU - Steele, Preston R.
AU - Sudario-Cook, Jordan
AU - Dumont, Elizabeth R.
AU - Ferry, Lara
N1 - Funding Information:
This work was supported by the National Science Foundation [IOS-1354189 to C.A.D.W.], [IOS- 1354166 to L.F.], and [IOS-1354240 to B.D.], [1IOS-539880] to Santana and Gignac. SICB DVM and DCB divisions, the University of Alaska Anchorage, and the University of Rhode Island.
Publisher Copyright:
© 2016 The Author 2016. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - The diet of dusky smoothhound sharks, Mustelus canis, shifts over ontogeny from soft foods to a diet dominated by crabs. This may be accompanied by changes in the skeletal system that facilitates the capture and processing of large and bulky prey. The hyoid arch, for example, braces the jaws against the cranium, and generates suction for prey capture and intraoral transport. In this study, ontogenetic changes in the hyoid arch were investigated by quantifying size, mineralization, and stiffness to determine whether increasingly stiffer cartilages are associated with the dietary switch. Total length and length of the hyomandibula and ceratohyal cartilages over ontogeny were the proxy for body size. Cross-sectional area, percent mineralization, and second moment of area were quantified in 28 individuals spanning most of the natural size range. Mechanical compression tests were conducted to compare flexural stiffness to size. Our results show that the morphological characters tested for the hyomandibular and ceratohyal cartilages scales isometrically with length. While stiffness of the hyomandibular and ceratohyal cartilages scales isometrically with length when assessed on morphological characters alone (second moment of area), this relationship becomes allometric when mechanical properties are included (flexural stiffness). Thus, while the hyoid arch elements grow isometrically, the mechanical properties dictate a scaling relationship that dwarfs morphological characteristics. The various combinations of morphologies and ontogenetic trajectories of chondrichthyan species illustrate the tremendous flexibility that they possess in the functional organization of the feeding apparatus.
AB - The diet of dusky smoothhound sharks, Mustelus canis, shifts over ontogeny from soft foods to a diet dominated by crabs. This may be accompanied by changes in the skeletal system that facilitates the capture and processing of large and bulky prey. The hyoid arch, for example, braces the jaws against the cranium, and generates suction for prey capture and intraoral transport. In this study, ontogenetic changes in the hyoid arch were investigated by quantifying size, mineralization, and stiffness to determine whether increasingly stiffer cartilages are associated with the dietary switch. Total length and length of the hyomandibula and ceratohyal cartilages over ontogeny were the proxy for body size. Cross-sectional area, percent mineralization, and second moment of area were quantified in 28 individuals spanning most of the natural size range. Mechanical compression tests were conducted to compare flexural stiffness to size. Our results show that the morphological characters tested for the hyomandibular and ceratohyal cartilages scales isometrically with length. While stiffness of the hyomandibular and ceratohyal cartilages scales isometrically with length when assessed on morphological characters alone (second moment of area), this relationship becomes allometric when mechanical properties are included (flexural stiffness). Thus, while the hyoid arch elements grow isometrically, the mechanical properties dictate a scaling relationship that dwarfs morphological characteristics. The various combinations of morphologies and ontogenetic trajectories of chondrichthyan species illustrate the tremendous flexibility that they possess in the functional organization of the feeding apparatus.
UR - http://www.scopus.com/inward/record.url?scp=85010280451&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85010280451&partnerID=8YFLogxK
U2 - 10.1093/icb/icw078
DO - 10.1093/icb/icw078
M3 - Article
C2 - 27371386
AN - SCOPUS:85010280451
SN - 1540-7063
VL - 56
SP - 442
EP - 448
JO - Integrative and comparative biology
JF - Integrative and comparative biology
IS - 3
ER -