Sex scandal in Washington...among fish.

Mercutio

Penultimate Amazing
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"Intersex" fish found in the Potomac River. Quite a few stories on Google News, but it looks like they all have the same original source.

So...any fish experts here? How unusual is this? Are other fish hermaphrodites? The news here suggested that the river water had elevated the fish's estrogen levels; is that speculation, or were tests run?

And where is Blinky?
 
would human estrogen effect estrogen levels in fish? Is it all the same stuff?
 
DDT and related pesticides are endocrine disruptors which mimic estrogen, another good reason for banning them.

Years ago alligators at Lake Apopka in Florida were found affected by this phenomenon. Males were basically emasculated and the females became super females or so the tale goes.

Search "Lake Apopka alligators" for more information.
 
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andyandy said:
would human estrogen effect estrogen levels in fish? Is it all the same stuff?
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Yes. But it's not human estrogen exactly that may be doing this but pesticides that mimic estrogen and disrupt normal endocrine function.

In reading the article the usual researchers are fishing around for an answer. After studying what happened to Apopka's alligators, I put my money on estrogen mimics and endocrine disrupting pesticide contamination.
 
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I wonder how this would effect fish who can switch genders? Also as it is the temp that determines sex in crocodilians does that change things as it is not the same as mamals?
 
ponderingturtle said:
I wonder how this would effect fish who can switch genders? Also as it is the temp that determines sex in crocodilians does that change things as it is not the same as mamals?
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Gender is determined in crocodilians and some turtles with respect to the
average incubating temperature of the eggs. Temperature does not affect
gender after hatching; in fact at some point during incubation (based on
incubation temperature ranges) gender is permanently determined and doesn't change. The temperatures and incubation time elapsed varies among different species. This is known as Temperature Dependent Sex Determination or TDS or TSD.

Mammals, with the exception of the Monotremes, do not lay external eggs subject to environmental temperature shifts. Incubation is held constant because they are incubated internally.

This situation involves the effect of a substance or contaminant such as DDT on endocrine function. In the Apopka alligators it has been documented to have ocurred in adults. I believe some species switch genders because there are not enough of the gender (switched to) to sustain population growth. This also may happen as a result of an endocrine shift.
 
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SteveGrenard said:
Gender is determined in crocodilians and some turtles with respect to the
average incubating temperature of the eggs. Temperature does not affect
gender after hatching; in fact at some point during incubation (based on
incubation temperature ranges) gender is permanently determined and doesn't change. The temperatures and incubation time elapsed varies among different species. This is known as Temperature Dependent Sex Determination or TDS or TSD.

Mammals, with the exception of the Monotremes, do not lay external eggs subject to environmental temperature shifts. Incubation is held constant because they are incubated internally.

This situation involves the effect of a substance or contaminant such as DDT on endocrine function. In the Apopka alligators it has been documented to have ocurred in adults. I believe some species switch genders because there are not enough of the gender (switched to) to sustain population growth. This also may happen as a result of an endocrine shift.
Click to expand...


I have seen in nature documentaries them saying that all of X species are born female, and when the male of an area dies the largest female in the area becomes the new male.

I just thought it was odd that the examples cited are both from species where sex is no nessacarily determined at conception(with bass I am not sure that it is not, so it is not that strong a relationship there).
 
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