Subject: hybrid between Dall's and harbour porpoise (Abstract) (fwd)

Mike Williamson (pita@www1.wheelock.edu)
Fri, 13 Mar 1998 11:53:50 -0500 (EST)

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---------- Forwarded message ----------
Date: Thu, 12 Mar 1998 12:56:31 -0400
From: "Robin W. Baird" <rwbaird@is.dal.ca>
To: MARMAM@UVVM.UVIC.CA
Subject: hybrid between Dall's and harbour porpoise (Abstract)

Baird, R.W., P.M. Willis, T.J. Guenther, P.J. Wilson and B.N.
White. 1998. An intergeneric hybrid in the family Phocoenidae.
Canadian Journal of Zoology 76:198-204.

Abstract

A 60 cm female fetus recovered from a Dall's porpoise (Phocoenoides
dalli) found dead in southern British Columbia was fathered by a
harbour porpoise (Phocoena phocoena). This is the first report of a
hybrid within the family Phocoenidae and one of the first
well-documented cases of cetacean hybridization in the wild. In
several morphological features, the hybrid was either intermediate
between the parental species (e.g., vertebral count) or more similar
to the harbour porpoise than the Dall's porpoise (e.g., colour
pattern, relative positioning of the flipper, dorsal fin height).
The fetal colour pattern (with a clear mouth-to-flipper stripe, as
is found in the harbour porpoise) is similar to that reported for a
fetus recovered from a Dall's porpoise off California. Hybrid status
was confirmed through genetic analysis, with species-specific
repetitive DNA sequences of both the harbour and Dall's porpoise
being found in the fetus. Atypically-pigmented porpoises (usually
traveling with and behaving like Dall's porpoise) are regularly
observed in the area around southern Vancouver Island. We suggest
these abnormally-pigmented animals, as well as the previously noted
fetus from California, may also represent hybridization events.





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Robin W. Baird, Ph.D.
Biology Department, Dalhousie University, 1355 Oxford St.,
Halifax, Nova Scotia B3H 4J1 Canada
Phone (902) 494-3723
Fax (902) 494-3736
e-mail: rwbaird@is.dal.ca
http://is.dal.ca/~whitelab/index.htm