If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

Genetic variation and evidence for population structure in eastern North Pacific false killer whales (Pseudorca crassidens)

$50.00 plus tax (Refund Policy)

Buy Article:

Abstract:

False killer whales (Pseudorca crassidens (Owen, 1846)) are incidentally taken in the North Pacific pelagic long-line fishery, but little is known about their population structure to assess the impact of these takes. Using mitochondrial DNA (mtDNA) control region sequence data, we quantified genetic variation for the species and tested for genetic differentiation among geographic strata. Our data set of 124 samples included 115 skin-biopsy samples collected from false killer whales inhabiting the eastern North Pacific Ocean (ENP), and nine samples collected from animals sampled at sea or on the beach in the western North Pacific, Indian, and Atlantic oceans. Twenty-four (24) haplotypes were identified, and nucleotide diversity was low (= 0.37%) but comparable with that of closely related species. Phylogeographic concordance in the distribution of haplotypes was revealed and a demographically isolated population of false killer whales associated with the main Hawaiian islands was identified (ΦST = 0.47, p< 0.0001). This result supports recognition of the existing management unit, which has geo-political boundaries corresponding to the USA’s exclusive economic zone (EEZ) of Hawai‘i. However, a small number of animals sampled within the EEZ but away from the near-shore island area, which is defined as<25nautical miles (1 nautical mile = 1.852 km) from shore, had haplotypes that were the same or closely related to those found elsewhere in the ENP, which suggests that there may be a second management unit within the Hawaiian EEZ. Biologically meaningful boundaries for the population(s) cannot be identified until we better understand the distribution and ecology of false killer whales.

Les fausses orques (Pseudorca crassidens (Owen, 1846)) sont à l’occasion capturées dans les pêches à la palangre dans le Pacifique Nord; on connaît cependant trop peu la structure de la population pour pouvoir évaluer l’impact de ces captures. Des données de séquençage de la région de contrôle de l’ADN mitochondrial (mtDNA) nous ont permis de mesurer la variation génétique chez cette espèce et d’évaluer la différentiation génétique entre les strates géographiques. Nos données comprennent 124 échantillons, dont 115 prélèvements de biopsie de la peau chez des fausses orques de l’est du Pacifique Nord (ENP) et neuf échantillons provenant d’animaux capturés en mer ou sur la plage dans l’ouest du Pacifique Nord, l’Atlantique et l’océan Indien. Il est possible d’identifier 24 haplotypes; la diversité des nucléotides est basse (= 0,37%), mais semblable à celle d’espèces fortement apparentées. Il y a une concordance phylogéographique dans la répartition des haplotypes; une population isolée démographiquement de fausses orques est associée avec les îles principales d’Hawai‘i (ΦST = 0,47, p < 0,0001). Cette observation vient appuyer la reconnaissance de l’unité de gestion actuelle qui possède des frontières géopolitiques qui correspondent à la zone économique exclusive des É.-U. (EEZ) à Hawai‘i. Cependant, un petit nombre d’animaux capturés dans l’EEZ, mais loin de la zone à proximité des îles (celle située à <25 milles nautiques (1 milles nautiques= 1.852km) des rivages) possèdent des haplotypes identiques ou presque à ceux trouvés ailleurs dans l’ENP; il peut donc y avoir une seconde unité de gestion au sein de l’EEZ d’Hawai‘i. Il n’est pas possible de définir des frontières de signification biologique pour la ou les populations tant que la répartition et l’écologie des fausses orques ne seront pas mieux comprises.

Document Type: Research Article

Publication date: July 1, 2007

More about this publication?
  • Published since 1929, this monthly journal reports on primary research contributed by respected international scientists in the broad field of zoology, including behaviour, biochemistry and physiology, developmental biology, ecology, genetics, morphology and ultrastructure, parasitology and pathology, and systematics and evolution. It also invites experts to submit review articles on topics of current interest.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more