Effects of hypophysectomy on the testis and secondary sex characters of the adult guppy Poecilia reticulata Peters

Abstract

PANDEY, S. 1969. Effects of hypophysectomy on the testis and secondary sex characters of the adult guppy Poecilia reticulata Peters. Can. J. Zool. 47: 775-781.Hypophysectomy of the adult guppy causes marked regression in the testis, completely blocks mitosis in the spermatogonia, and prevents their wansformation into spermatocytcs. However, sperrnatocytes, spermatih, and s p c m already prcsent in the testis at the time of operation develop into spmnatophores. The spermatophores rupture after 8 weeks and the rrsullmp sperm are phagocyfosed within the sperm ducts. The epithelial cells llning the sperm ducts, the Sertoli cells, and the interstitial cells regrcw. Of two particularly well-differentiated secondary sex characters, the gonopod~um (modified anal fin) remains unaffected, white the patches of br~ght lipophores (vellow and red p~gments) present on the sides ol the body become fain1 or entirely disappear. IntroductionThe effects of hypophysectomy on the testes and secondary sex characters of teleosts have been reviewed by several investigators (Pickford and Atz

Antiandrogenic Pesticides Disrupt Sexual Characteristics in the Adult Male Guppy (Poecilia reticulata)

“…First, the affected sex characteristics are known to be under androgen control in the guppy (32,(41)(42)(43). Thus, Pandey (32) blocked the synthesis of sex steroids in adult male guppies by hypophysectomy, which caused a marked regression in the testis, inhibition of spermatogenesis, and a pronounced fading of the orange display coloration.…”

“…His anal fin is developed into a copulatory organ (the gonopodium) for internal fertilization, and ejaculates of sperm can be evacuated for sperm counting without harming the fish (30,31). The hormonal pathways controlling the expression of the male sexual characteristics are not fully understood, but sperm production, body coloration, and courtship behavior are known to be regulated by androgens (32)(33)(34). Hence, the male guppy offers a suite of sexual characteristics that are both accessible for quantification and of relevance for the study of EDCs on reproduction.…”

Sexual Characteristics Are Altered by 4-tert-Octylphenol and 17β-Estradiol in the Adult Male Guppy (Poecilia reticulata)

“…The proportion of the body surface covered by orange spots increases with age so that the oldest and largest males have the most conspicuous coloration. The coloration of male guppies is 81 ESTROGENIC COMPOUNDS AFFECT GUPPY SEXUAL CHARACTERISTICS known to be androgen dependent (Pandey, 1969). Discoloring of the orange spots has previously been reported in response to chemical and natural stressors, including estrogen (Berkowitz, 1941), food quality (Kodric-Brown, 1989), and parasites (Houde and Torio, 1992).…”

Histopathological Effects in Poecilia reticulata (Guppy) Exposed to Methyl Mercury Chloride

“…Once spermiogenesis is complete, the spermatogenetic units (cystic clusters of spermatozoa, &dquo;spermatophora&dquo; or &dquo;spermatozeugmata&dquo;) are packed in the main ducts (Fig. 8A) (23).…”