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Amby

global warming may produce too many male fish

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Many reptiles have no sex chromosomes. Instead, their gender is determined by temperature. In crocodiles, for example, males are hot: eggs incubated in sand above a certain “pivotal temperature” almost always hatch males. That could spell trouble, because Earth is warming so fast that natural selection may not have time to adjust pivotal temperatures. Female crocodiles may become scarce.

Some experts think fish are in the same hot water because temperature-dependent sex determination, or TSD, occurs in many species. But a critical analysis of the fish literature by Natalia Ospina-Álvarez and Francesc Piferrer, both of the Marine Science Institute in Barcelona, Spain, casts doubt on that assertion.

The pair point out that fourteen of the twenty diverse fish genera previously reported as having TSD in fact have sex chromosomes, and that it takes unnatural temperatures found only in the laboratory to masculinize their genetic females.

But the six genera that do show true TSD, including the Menidia silversides and the Apistogramma cichlids, could see their sex ratios skewed by global warming. And Ospina-Álvarez and Piferrer found that males were hot in all six.

The researchers calculated that in such temperature-sensitive fishes — and there might well be many more than just six genera — a rise of 7 Fahrenheit degrees predicted by some models for the end of the century would yield three males for every female, a ratio unfavorable for maintaining populations.

The findings were detailed in the journal PloS ONE.

http://www.livescience.com/animals/081215-nhm-hot-fish.html


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Hey Al! could you come oover and get my internet working. :luv:


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Filed: K-1 Visa Country: Ukraine
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Well well well according to our resident gay marriage activist on here, that is not going to be any problem for fish can be gay also, what does it matter and so what if they are all male it does not matter that there might not be anymore fish ever or a shortage, they had their gay marriage fish rights upheld!

Many reptiles have no sex chromosomes. Instead, their gender is determined by temperature. In crocodiles, for example, males are hot: eggs incubated in sand above a certain “pivotal temperature” almost always hatch males. That could spell trouble, because Earth is warming so fast that natural selection may not have time to adjust pivotal temperatures. Female crocodiles may become scarce.

Some experts think fish are in the same hot water because temperature-dependent sex determination, or TSD, occurs in many species. But a critical analysis of the fish literature by Natalia Ospina-Álvarez and Francesc Piferrer, both of the Marine Science Institute in Barcelona, Spain, casts doubt on that assertion.

The pair point out that fourteen of the twenty diverse fish genera previously reported as having TSD in fact have sex chromosomes, and that it takes unnatural temperatures found only in the laboratory to masculinize their genetic females.

But the six genera that do show true TSD, including the Menidia silversides and the Apistogramma cichlids, could see their sex ratios skewed by global warming. And Ospina-Álvarez and Piferrer found that males were hot in all six.

The researchers calculated that in such temperature-sensitive fishes — and there might well be many more than just six genera — a rise of 7 Fahrenheit degrees predicted by some models for the end of the century would yield three males for every female, a ratio unfavorable for maintaining populations.

The findings were detailed in the journal PloS ONE.

http://www.livescience.com/animals/081215-nhm-hot-fish.html

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Filed: AOS (apr) Country: Colombia
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Global warming is also causing an excess of available female human beings, not bad if you are a guy with thousands to choose from.

Which Global Warming was that and... more importantly, what does that have to do with humans being aquatic creatures?

:P

(But like the article hints at... we mammals have sex chromosomes... and hint#2- humans undergo sex tract degeneration in our embryonic development. Read up on Mullerian vs Wolffian duct degeneration)


Wishing you ten-fold that which you wish upon all others.

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