TY - JOUR
T1 - Skull morphometric variability related to offshore and inshore ecotypes of the common bottlenose dolphin (Tursiops truncatus) from northwestern Mexico
AU - Esteves-Ponte, María Alejandra
AU - Aurioles-Gamboa, David
AU - García-Rodríguez, Francisco J.
N1 - Publisher Copyright:
© 2022 Society for Marine Mammalogy.
PY - 2022/7
Y1 - 2022/7
N2 - The distribution of common bottlenose dolphins Tursiops truncatus is associated with environmental factors, which influence morphological adaptations. In the present study, we examined the cranial characteristics of this species from the Pacific Northwest of Mexico to detect the main variations using geometric morphometric analysis. From stable isotope concentrations (δ13C), we identified 24 specimens of the inshore coastal ecotype and 18 of the offshore ecotype. Maturity was determined using the degree of fusion of the maxillae and premaxillae. Allometry was detected in the skull lateral region, indicating that the relationship between shape and size is maintained in adults. After eliminating the allometric effect by discarding the smallest individuals, morphometric comparisons indicated differences between the ecotypes that were associated mainly with the intersection between the frontal bone and zygomatic process, the anteriormost point in the curvature of the zygomatic process, and the meeting of the suture between squamosal and exoccipital bones, with the supramastoid crest to anteriormost in the curvature of the temporal crest of the intersection between the parietal and interparietal. No significant differences were found in the ventral view. The cranial differences between both Tursiops truncatus ecotypes could be mainly associated with the different types of feeding.
AB - The distribution of common bottlenose dolphins Tursiops truncatus is associated with environmental factors, which influence morphological adaptations. In the present study, we examined the cranial characteristics of this species from the Pacific Northwest of Mexico to detect the main variations using geometric morphometric analysis. From stable isotope concentrations (δ13C), we identified 24 specimens of the inshore coastal ecotype and 18 of the offshore ecotype. Maturity was determined using the degree of fusion of the maxillae and premaxillae. Allometry was detected in the skull lateral region, indicating that the relationship between shape and size is maintained in adults. After eliminating the allometric effect by discarding the smallest individuals, morphometric comparisons indicated differences between the ecotypes that were associated mainly with the intersection between the frontal bone and zygomatic process, the anteriormost point in the curvature of the zygomatic process, and the meeting of the suture between squamosal and exoccipital bones, with the supramastoid crest to anteriormost in the curvature of the temporal crest of the intersection between the parietal and interparietal. No significant differences were found in the ventral view. The cranial differences between both Tursiops truncatus ecotypes could be mainly associated with the different types of feeding.
KW - Tursiops truncatus
KW - bottlenose dolphins
KW - ecotypes
KW - landmarks
KW - skull shape
UR - http://www.scopus.com/inward/record.url?scp=85124508578&partnerID=8YFLogxK
U2 - 10.1111/mms.12914
DO - 10.1111/mms.12914
M3 - Artículo
AN - SCOPUS:85124508578
SN - 0824-0469
VL - 38
SP - 1088
EP - 1103
JO - Marine Mammal Science
JF - Marine Mammal Science
IS - 3
ER -