title: Norethindrone-induced masculinization and progeny testing in guppy, Poecilia reticulata (Peters 1859).
abstract: Norethindrone(NE) was evaluated for its efficacy on alteration of sex ratio of P. reticulata. Either the young fry or the brooders and the resultant fry were fed a commercial diet incorporated with NE at 0, 25, 50, 75 and 100 mg kg(-1) diet (ppm) for 30-40 d in rectangular glass aquaria; this was followed by 40-60 d rearing on NE-free diet in out-door concrete tanks. In general, the androgen treatment altered sex ratio, leading to the production of a dose dependent increase in the percentage of males. The oral administration of the steroid at 75 ppm for 40 d or 100 ppmfor 30 or 40 d to first feeding fry, yielded 100% males. On the other hand, NE administration to brooders before parturition and the resultant fry also produced an all-male population of guppy. The sex ratio of the untreated control was almost 1:1. The survival of fish in all the trials was high, ranging between 67 and 100%. Mating masculinized males ("XX" male) with normal female resulted in an all-female progeny, while crossing normal male (XY) from treatment groups with normal female sired normal sex ratio (1:1), elucidating XX-XY sex determination system in the guppy.
authors.forename: N
authors.initials: N
authors.lastname: Basavaraja
authors.forename: B H
authors.initials: BH
authors.lastname: Chandrashekhara
authors.forename: Rather Mansoor
authors.initials: RM
authors.lastname: Ahamad
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D009640:Norethindrone / Q000494:pharmacology*; D011036:Poecilia / Q000235:genetics / Q000254:growth & development*; D012098:Reproduction / Q000235:genetics; D019849:Sex Determination Processes / Q000187:drug effects*; D012744:Sex Ratio
chemical_list: D009640:Norethindrone