Gonad Morphology And Social Influence On Gonad Development Of The Juvenile Divine Dwarfgoby, Eviota Epiphanes(Teleostei: Gobiidae)

dc.contributor.author de Souza Brasil Barreto, Helena
dc.date.accessioned 2019-05-28T20:45:33Z
dc.date.available 2019-05-28T20:45:33Z
dc.date.issued 2018-05
dc.identifier.uri http://hdl.handle.net/10125/62845
dc.subject bi-directional
dc.subject hermaphroditism
dc.subject Eviota epiphanes
dc.subject ovotestis
dc.subject sex differentiation
dc.title Gonad Morphology And Social Influence On Gonad Development Of The Juvenile Divine Dwarfgoby, Eviota Epiphanes(Teleostei: Gobiidae)
dc.type Thesis
dcterms.abstract Social factors can have significant effects on sexual development and sex allocation strategies in juveniles of many coral reef fishes. However, much about the diversity of reproductive strategies remains to be explored in the many species coral reef fishes. This study examined the process of gonad development and tested for social control of first sexual differentiation in juveniles of the hermaphroditic goby, Eviota epiphanes. This small, cryptic species is native to the Hawaiian Islands and empirical data from previous studies have shown that adult E. epiphanes can alternate sexual function in response to social cues. Thus, social experiments were maintained to access the possible role of social factors, specifically the presence of another conspecific of similar body size, on gonad development and sexual function in juveniles. We hypothesized that the relative proportions of ovarian and testicular tissues present in the developing gonad of E. epiphanes prior to sexual maturity varies significantly in response to the presence of another conspecific. Social pairs were established based on similarity in body sizes and were maintained in individual laboratory tanks. Following the end of the two-week experimental period, some fish had achieved adulthood, indicated by the sexually distinctive papilla morphology and by the presence of mature gametes identified histologically. A non-experimental group, composed of wild caught juveniles was used to examine gonad morphology prior to sexual maturity. All gonads were assessed histologically and the results showed that there was a statistically significant difference in the proportion of spermatogenic to oogonia tissues appropriated in the gonads of paired individuals. This study demonstrated for the first time that social context affects sexual differentiation in E. epiphanes juveniles.
dcterms.description M.S. Thesis. University of Hawaiʻi at Mānoa 2018.
dcterms.language eng
dcterms.publisher University of Hawaiʻi at Mānoa
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dcterms.type Text