Head adaptation for sound production and feeding strategy in dolphins (Odontoceti: Delphinida).

Autor: Frainer G; Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil., Huggenberger S; University of Witten/Herdecke gGmbH, Witten, Germany., Moreno IB; Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.; Centro de Estudos Costeiros, Limnológicos e Marinhos (CECLIMAR/CLN/UFRGS), Universidade Federal do Rio Grande do Sul, Imbé, Brazil., Plön S; Bayworld Centre for Research and Education (BCRE), Port Elizabeth, South Africa., Galatius A; Marine Mammal Research, Department of Bioscience, Aarhus University, Roskilde, Denmark.
Jazyk: angličtina
Zdroj: Journal of anatomy [J Anat] 2021 May; Vol. 238 (5), pp. 1070-1081. Date of Electronic Publication: 2020 Dec 14.
DOI: 10.1111/joa.13364
Abstrakt: Head morphology in toothed whales evolved under selective pressures on feeding strategy and sound production. The postnatal development of the skull (n = 207) and mandible (n = 219) of six Delphinida species which differ in feeding strategy but exhibit similar sound emission patterns, including two narrow-band high-frequency species, were investigated through 3D morphometrics. Morphological changes throughout ontogeny were demonstrated based on the main source of variation (i.e., prediction lines) and the common allometric component. Multivariate trajectory analysis with pairwise comparisons between all species was performed to evaluate specific differences on the postnatal development of skulls and mandibles. Changes in the rostrum formation contributed to the variation (skull: 49%; mandible: 90%) of the entire data set and might not only reflect the feeding strategy adopted by each lineage but also represents an adaptation for sound production and reception. As an important structure for directionality of sound emissions, this may increase directionality in raptorial feeders. Phylogenetic generalized least squares analyses indicated that shape of the anterior portion of the skull is strongly dependent on phylogeny and might not only reflect feeding mode, but also morphological adaptations for sound production, particularly in raptorial species. Thus, postnatal development seems to represent a crucial stage for biosonar maturation in some raptorial species such as Pontoporia blainvillei and Sousa plumbea. The ontogeny of their main tool for navigation and hunting might reflect their natural history peculiarities and thus potentially define their main vulnerabilities to anthropogenic changes in the environment.
(© 2020 Anatomical Society.)
Databáze: MEDLINE
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