Male Anal Fin Research Articles

Inhibition of pituitary gonadotrophic activity in the viviparous seaperch Cymatogaster aggregata Gibbons by a dithiocarbamoylhydrazine derivative (I.C.I. 33 828).

A suspension of Methallibure (I.C.I. Compound 33 828) was added regularly for about 6 weeks to aquaria housing males of the teleost Cymatogaster aggregata. The testis atrophied and the gametogenetic processes of maturation were suspended. Histochemically demonstrable 3β-hydroxysteroid dehydrogenase and sudanophilic lipids diminished and the interstitial cells of Leydig regressed. At the end of the experiments the fleshy modifications on the male anal fin (secondary sex structures which develop under the influence of male gonadal hormones) were in a state characteristic of immature fish. Methallibure treatment resulted in these changes, which were characteristic of hypophysectomy, without the marked antithyroid activity histologically evident in thiourea treatment. All thiourea-treated and control animals remained in breeding condition. It is concluded that the addition of Methallibure to the aquarium water will directly block the production and (or) release of pituitary gonadotropins and thus inhibit spermatogenesis and testicular steroidogenesis.

A New Key Character in Males of the Family Goodeidae (Cyprinodontiformes)

IN the family Goodeidae, unlike the other viviparous Cyprinodontiformes, the male anal fin is not modified into a gonopodium. Three years ago, we discovered in Skiffia lermae (Goodeidae) a muscular structure which seems to serve as a reproductive organ and which we called a “pseudo-penis”1,2. This structure consists of a substantial muscular mass situated just behind the visceral cavity; it surrounds (a) a highly dilated vas deferens, the internal surface of which presents numerous villosities, and (b) a urinary canal.

GONOPODIAL CHARACTERISTICS PRODUCED IN THE ANAL FINS OF FEMALES OF GAMBUSIA AFFINIS AFFINIS BY TREATMENT WITH ETHINYL TESTOSTERONE

Previous articleNext article No AccessJournal ArticlesGONOPODIAL CHARACTERISTICS PRODUCED IN THE ANAL FINS OF FEMALES OF GAMBUSIA AFFINIS AFFINIS BY TREATMENT WITH ETHINYL TESTOSTERONEC. L. TURNERC. L. TURNER Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Biological Bulletin Volume 80, Number 3June 1941 Published in association with the Marine Biological Laboratory Article DOIhttps://doi.org/10.2307/1537723 Views: 46Total views on this site Citations: 1Citations are reported from Crossref © 1941 Marine Biological LaboratoryPDF download Crossref reports the following articles citing this article: William N. Tavolga Effects of Gonadectomy and Hypophysectomy on Prespawning Behavior in Males of the Gobiid Fish, Bathygobius soporator, Physiological Zoology 28, no.33 (Sep 2015): 218–233.https://doi.org/10.1086/physzool.28.3.30159918