Show simple item record

Share 
 
dc.contributor.authorQuinitio, Gerald F.
dc.contributor.authorGoto, Akira
dc.contributor.authorTakahashi, Hiroya
dc.date.accessioned2013-02-04T07:03:46Z
dc.date.available2013-02-04T07:03:46Z
dc.date.issued1992
dc.identifier.citationQuinitio, G. F., Goto, A., & Takahashi, H. (1992). A comparison of the annual changes in testicular activity and serum androgen levels between the early and delayed maturing groups of male Cottus hangiongensis. Environmental Biology of Fishes, 34(2), 119–126.en
dc.identifier.issn0378-1909
dc.identifier.urihttp://hdl.handle.net/10862/1392
dc.description.abstractAnnual changes in testicular activity and concentration of two serum androgens were monitored in two groups of the river-sculpin Cottus hangiongensis collected from the upper and lower reaches of a river at southern Hokkaido, Japan. One of them (early maturing group) underwent testicular maturation with aberrant spermatids and spermatid masses produced during the reproductive cycle. Moreover, regular seasonal changes in serum testosterone and 11-ketotestosterone concentrations were observed. On the other hand, in the other group (delayed maturing group), although body size of the fish was large enough to undergo reproduction, annual changes in gonadosomatic index and testicular activity did not vary much. During the months of active testicular development in the early maturing group, spermatogenesis was observed to begin in some regions of the testes of delayed maturing fish, but always resulted in the formation of aberrant spermatids and spermatid masses. Moreover, concentration of serum androgens did not significantly vary throughout the year. Results suggest that low androgen production is a proximal factor for delayed sexual maturity in the delayed maturing group, and that the occurrence of aberrant spermatids and spermatid masses during spermatogenesis is not linked to the delayed maturity.en
dc.language.isoenen
dc.publisherSpringer Verlagen
dc.subjectCottus hangiongensis
dc.subjectJapanen
dc.titleA comparison of the annual changes in testicular activity and serum androgen levels between the early and delayed maturing groups of male Cottus hangiongensisen
dc.typeArticleen
dc.citation.volume34
dc.citation.issue2
dc.citation.spage119
dc.citation.epage126
dc.citation.journalTitleEnvironmental Biology of Fishesen
dc.subject.asfaAnimal reproductive organsen
dc.subject.asfaAnnual variationsen
dc.subject.asfaFreshwater fishen
dc.subject.asfaMalesen
dc.subject.asfaSex hormonesen
dc.subject.asfaSexual maturityen
dc.subject.asfaTestesen
dc.identifier.doi10.1007/BF00002387


Files in this item

FilesSizeFormatView

This item appears in the following Collection(s)

  • AQD [1129]
    These papers were contributed by AQD staff to various national and international journals

Show simple item record