arnould-ontogenyofbodysize-2007.pdf (147.2 kB)
Download file

Ontogeny of body size and shape of Antarctic and subantarctic fur seals

Download (147.2 kB)
journal contribution
posted on 2007-01-01, 00:00 authored by S Luque, E Miller, John ArnouldJohn Arnould, M Chambellant, C Guinet
Pre- and post-weaning functional demands on body size and shape of mammals are often in conflict, especially in species where weaning involves a change of habitat. Compared with long lactations, brief lactations are expected to be associated with fast rates of development and attainment of adult traits. We describe allometry and growth for several morphological traits in two closely related fur seal species with large differences in lactation duration at a sympatric site. Longitudinal data were collected from Antarctic (Arctocephalus gazella (Peters, 1875); 120 d lactation) and subantarctic (Arctocephalus tropicalis (Gray, 1872); 300 d lactation) fur seals. Body mass was similar in neonates of both species, but A. gazella neonates were longer, less voluminous, and had larger foreflippers. The species were similar in rate of preweaning growth in body mass, but growth rates of linear variables were faster for A. gazella pups. Consequently, neonatal differences in body shape increased over lactation, and A. gazella pups approached adult body shape faster than did A. tropicalis pups. Our results indicate that preweaning growth is associated with significant changes in body shape, involving the acquisition of a longer, more slender body with larger foreflippers in A. gazella. These differences suggest that A. gazella pups are physically more mature at approximately 100 d of age (close to weaning age) than A. tropicalis pups of the same age

History

Journal

Canadian journal of zoology

Volume

85

Issue

12

Pagination

1275 - 1285

Publisher

NRC Research Press

Location

Ottawa, Ontario

ISSN

1480-3283

Language

eng

Publication classification

C1 Refereed article in a scholarly journal; C Journal article

Copyright notice

2007, NRC Canada