....scientists found 11 out of 82 male hornyhead turbot collected off the Southern California coast had small eggs growing in their testes.
Not necessarily. Do these scientists have a historic baseline for the normal condition of hornyhead turbot indicating that this condition is unusual for that species?
Of the vertebrates in the animal kingdom, sex determination is usually a fixed characteristic in terms of life history. Interestingly, there are a few organisms for whom sex is a plastic condition, often determined by a combination of internal and external signals. One such group of organisms which follows this trend are the tropical teleosts: the conspicuous coloful fish inhabiting coral reefs.
It would seem sexual plasticity, or at least its potential, may not be uncommon in fish. This could well be more eco-fear-mongering.
posted on 11/28/2005 8:01:42 AM PST
(The environment is too complex and too important to manage by central planning.)
It would seem sexual plasticity, or at least its potential, may not be uncommon in fish.
True, fish are fairly plastic organisms, even in terms of sex. But as your quote said it often "determined by a combination of internal and external signals." Estrogen mimics seem like pretty good signals to me.
Further, there seems to be a ton of research on the hornyhead turbot and none i can find historically document any signs of feminization (not to say it didn't occur). Here is an older paper that makes no mention of it Aspects of the Life History of Hornyhead Turbot, Pleuronichthys verticalis, off Southern California and cites that they are heavily monitored due to their accumulation of metals and chlorinated hydrocarbons.
posted on 11/28/2005 8:33:33 AM PST
(Not blind opposition to progress, but opposition to blind progress)
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