On Tuesday, March 18, 2003, at 01:37 PM, Joe Tanzola wrote:
> What animal has the highest chromosome count?
There is variation in chromosome counts of animals going from the most
simple, single-celled animals (with few chromosomes) on up to the
highest vertebrates. Since this program focuses on whales, I will focus
the answer to your question on that subject. (With thanx to Scott Baker
for some details)
There is a good overview of cetacean chromosomal variety in Rice
(1998). Cetaceans overall have a very conserved karyotype (compared
for example to ungulates). The Balaenopteridae have 2n = 44 and
Balaenidae 2n = 42. For Odonotoceti, again the general is 2n = 44 but
some beaked whales have 2n = 42. The sperm whale also has 2n = 44 but I
think that the reduction is for different reasons in each case (i.e.,
the 2n = 42 for sperm if not the same as beaked whales). Debbie
Duffield did most of the early work on karyotyping along with Arnason.
There are several species that have yet to be karyotyped (including
many beaked whales and the pygmy right). Below is the only reference
for the humpback.
Lambertsen, R. H., C. S. Baker, D. O. Duffield, and J. Chamberlin-Lea.
1988. Cytological determination of sex among individually identified
humpback whales (Megaptera novaeangliae). Can. J. Zool. 66:1243-1248.
If you would like to look further into this subject, I'll direct you to
the following web site:
> whale and dolphin identification website
> website of the Molecular Ecology and Evolution Laboratory
> select Molecular Ecology and Evolution
Alaska Whale Foundation
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