northern bottlenose whales, Hyperoodon ampullatus

From: pita admininstrator (pita@www1.wheelock.edu)
Date: Thu Mar 22 2001 - 10:43:05 EST


Subject: New publication

New publication

Genetic diversity and population structure among northern bottlenose whales,
Hyperoodon ampullatus, in the western North Atlantic Ocean
Canadian Journal of Zoology 79: 478-484
M.L. Dalebout, S.K. Hooker, and I. Christensen

Abstract: To assess population structure and genetic diversity among
northern bottlenose whales (Hyperoodon ampullatus), we compared
mitochondrial DNA control region sequences from three populations in the
western North Atlantic Ocean. Skin-biopsy samples were collected from
animals in the Gully off Nova Scotia, Canada, in 1996 and 1997 (n = 20), and
teeth were obtained from whales taken in Davis Strait off northern Labrador
(n = 20) and off northern Iceland (n = 5) between 1967 and 1971 by the
historical Norwegian fishery. Only low levels of genetic diversity were
found among the 45 animals sampled (three polymorphic sites over 434 base
pairs defining four haplotypes; haplotype diversity (h) = 0.57, nucleotide
diversity (p) = 0.0015). The cause of this low variability is unclear but
may be due to a possible bottleneck event associated with the last
glaciation. The distribution of mitochondrial DNA haplotypes between the
Gully and Davis Strait populations was suggestive of regional
differentiation (FST = 0.118, P = 0.024; FST = 0.145, P = 0.007). Animals
taken off northern Iceland were not included in statistical analyses of
population structure, owing to the small sample size. These data, in
conjunction with other information collected to date, indicate that the
Gully and Davis Strait populations should be considered separate stocks for
management purposes.

Risumi : Pour ivaluer la structure des populations et la diversiti ginitique
chez la Baleine ` bec commune (Hyperoodon ampullatus), nous avons compari
les siquences de la rigion de contrtle de l'ADN mitochondrial de trois
populations de l'ouest de l'Atlantique-Nord. Des biopsies de la peau ont iti
pratiquies sur des baleines du Gully, au large de la Nouvelle-Icosse,
Canada, en 1996 et 1997 (n = 20), et des dents ont iti prilevies chez des
baleines du ditroit de Davis capturies au large de la ctte nord du Labrador
(n = 20) et au large de l'Islande (n = 5) entre 1967 et 1971 au cours des
pjches commerciales de Norvhge de l'ipoque. La diversiti ginitique s'est
avirie faible chez les 45 animaux itudiis (trois sites polymorphes sur 434
paires de bases difinissant quatre haplotypes; la diversiti d'haplotype (h)
= 0,57, la diversiti de nucliotide (p) = 0,0015). La cause de cette faible
variabiliti reste obscure, mais il est possible qu'il se soit produit un
ivinement aboutissant ` un itranglement ginitique au cours de la dernihre
glaciation. La ripartition des haplotypes d'ADNmt entre le Gully et le
ditroit de Davis laisse croire ` l 'existence d'une diffirenciation
rigionale (FST = 0,118, P = 0,024; FST = 0,145, P = 0,007). Les ichantillons
du nord de l'Islande n'ont pas iti retenus pour les analyses statistiques de
la structure des populations car ils sont trop restreints. Ces donnies,
combinies ` d'autres informations recueillies ` ce jour, indiquent que les
populations du Gully et du ditroit de Davis doivent jtre considiries comme
des stocks diffirents pour fins d'aminagement.

A small number of reprints will be available from Merel Dalebout
(m.dalebout@auckland.ac.nz)

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