Virgin Shark Birth Mystery

RICHMOND, Va. (AP) - Scientists are confirming the second case
of a "virgin birth" in a shark.
The Journal of Fish Biology reports that scientists say DNA
testing proves that a pup carried by a female Atlantic blacktip
shark in the Virginia Aquarium & Marine Science Center contained no
genetic material from a male.
The first documented case of asexual reproduction, or
parthenogenesis, among sharks involved a pup born to a hammerhead
at an Omaha, Neb., zoo.
Shark scientist Demian Chapman says "it is quite possible that
this is something female sharks of many species can do on
occasion."
Scientists say absent the chromosomes present in the male sperm,
the offspring of an asexual conception may be at a disadvantage for
surviving in the wild.
Virgin birth has been proven in some bony fish, amphibians,
reptiles and birds, and has been suspected among sharks in the
wild.

(Copyright 2008 by The Associated Press. All Rights Reserved.)