Sewage linked to fish-gender quirks.During dry spells, the water in some streams can come mostly from municipal sewage-treatment plants. A new study finds reproductive impairments among fish residing in such waters.
Alan Vajda and his colleagues at the University of Colorado University of Colorado may refer to:
Fish upstream of a Boulder treatment plant were fairly evenly divided between males and females. However, 93 percent of the 60 fish caught downstream in the same river were females. Ovaries Ovaries
The female sex organs that make eggs and female hormones.
Mentioned in: Choriocarcinoma
ovaries (ō´v in many of these fish were smaller than those in their upstream cousins, contained testicular testicular /tes·tic·u·lar/ (tes-tik´u-lar) pertaining to a testis.
Of or relating to a testicle or testis.
pertaining to the testis. tissue, bore an unusual shape, and held less-developed eggs.
Of 21 fish captured downstream of a Denver water-treatment plant, 81 percent were females and all of the males there had testes testes
Male reproductive organs (see reproductive system). Humans have two oval-shaped testes 1.5–2 in. (4–5 cm) long that produce sperm and androgens (mainly testosterone), contained in a sac (scrotum) behind the penis. containing ovarian tissue.
The sex ratio downstream of the one Colorado Springs sewage-treatment plant was close to normal, but Vajda notes, "We still found intersex intersex /in·ter·sex/ (in´ter-seks)
female intersex a female pseudohermaphrodite. fish," which have gonads containing male and female tissue.
What's shocking, Vajda told Science News, is that the source of pollutants at the Colorado sites isn't industry, but flushed toilets.
Vajda and his colleagues are now looking to tie the gender bending of fish to particular pollutants and to find out whether the extra downstream females are the products of a selective die-off of males or a pollutant-triggered sex reversal sex reversal
A process that changes the sexual identity of an individual from one sex to the other, often through a combination of surgical, pharmacologic, and psychiatric procedures. .--J.R