Effects of some steroids and other compounds on ovarian growth fo the red swamp crayfish, Procambarus clarkii, during vitellogenesis.

RODRÍGUEZ, E.M.; MEDESANI, D.A.; LÓPEZ GRECO, L.S.; FINGERMAN, M.

JOURNAL OF EXPERIMENTAL ZOOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 2002 vol. 292 p. 82 - 87

0022-104X

The effects of spiperone, a dopaminergic receptor blocker, the terpenoid JHIII and the steroids 17alfa-hydroxyprogesterone and 17beta-estradiol (10-7 mol/crayfish) were assayed in vivo, on females of the red swamp crayfish, Procambarus clarkii, during early vitellogenesis. All these compounds were injected twice a week for three weeks. The rate of molting was also determined. At the end of the experiment the ovaries were dissected out, in order to determine the gonadosomatic indexes and the oocyte diameters. Spiperone, 17alfa-hydroxyprogesterone and 17beta-estradiol produced a significant increase in gonadosomatic index, while only the first two compounds were able to significantly increase the oocyte diameter; therefore, the effect of 17beta-estradiol on gonadosomatic could be merely due to an increased water uptake by the ovary. Spiperone could be causing a decrease in the secretion of gonad and/or mandibular inhibiting hormones  from the eyestalks, and 17alfa-hydroxyprogesterone could be having a direct stimulatory effect on vitellogenin production. Concerning molting, of the compound tested, only JHIII had a significant (p<0.05)  stimulatory effect,  producing a 100 % molting  rate versus 66.7 % among the controls.