ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
Immersion of 1-day-old Silurus asotus (Linnaeus) larvae in 50, 100 or 200 μg L−1 oestradiol-17β for 15 days altered gonad differentiation and gonadal morphology. The survival of the group immersed at the highest dose (200 μg L−1) was reduced significantly (86%), whereas survival of the groups immersed at the lower doses was as high as that of untreated controls (94%). The sex ratio of the untreated group was close to 1:1 (female–male); however, the incidence of females was significantly higher in groups immersed in doses of 50, 100 and 200 μg L−1, i.e. 86%, 92% and 99.4%, respectively. Ovarian morphology of feminized individuals was different to that of the controls; the ovary was morphologically rather similar to testis although it contained fully matured oocytes. Morphological changes in genital organs were also noted in fish exposed to oestradiol-17β the shape and size of genital papilla were intermediate between those of normal male and female. During a 4-month growth trial after the exposure, the feminized fish showed significantly improved growth performance over normal genetic males (P 〈 0.05), although the growth was not equal to that of normal genetic females (P 〈 0.05).
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1046/j.1365-2109.2001.00559.x
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