Nancy J. Schmitt
One of the ways that an endocrine disruptor works is that the chemical makes an organism produce more enzyme aromatase which then converts androgen hormones to estrogen hormones. Androgen hormones are those chemicals, like steroids that control the development and maintenance of masculine characteristics in vertebrates. This includes the activity of the male sex organs and development of male sex characteristics. Androgens are also the precursor of all estrogens, the female sex hormones. The primary and most well-known androgen is testosterone. Androgens play a major role in the development and maintenance of masculine secondary sexual characteristics.
In fish androgen hormones affect male aggression,
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reproductive capability and defense of the young.
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In frogs androgen hormones also impact reproductive capability. This includes the size of the voice box which in males must produce the desired mating call for reproduction to occur.
Once the frog or fish has more female hormones than male hormones, its characteristics start becoming female. This includes having the ability to have precursors to eggs and in some cases actual eggs. The voice of the male frog also changes and is not of the same quality as a normal male frog. The voice box, which is smaller than normal impacts the capability to produce a recognizable the mating call.
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The endocrine disruptors that are now found in our water have been implicated as the cause of the feminization of the frogs and fish. The changes that have effectively feminized the fish and frogs may impact these organisms' ability to reproduce.