The Israeli Journal of Aquaculture – Bamidgeh
56(2), 2004, 102-112.
EFFECTS OF FRESH WATER AND SEA WATER ON GROWTH,
ESTRADIOL-17b CONCENTRATION AND
OVARIAN DEVELOPMENT IN JUVENILE TILAPIA
Tulay Altun*, Ercan Sar.han
The Faculty of Fisheries, Cukurova University, 01330 Balcali Adana, Turkey
Levent Kayr.n and Figen Doran
Medical Faculty, Cukurova University, 01330 Balcali Adana, Turkey
(Received 14.1.03, Accepted 26.1.04)
Key words: fresh water, Oreochromis niloticus, O. aureus, ovarian development, sea water,
The effects of fresh water and sea water on growth, estradiol-17b levels, ovarian and oocyte
development of Oreochromis niloticus, O. aureus and Tilapia zilli were determined. Sea water
affected growth positively (p<0.05) but estradiol-17b concentrations in fish reared in sea water
did not reach the levels in fish reared in fresh water. Ovarian stages developed differently in sea
and fresh water. Ovulation occurred only when the fish were grown in fresh water whereas
mature and atretic oocytes were seen simultaneously in all species when grown in sea water.
There were no statistically significant differences in oocyte diameter between the groups grown
in fresh and sea water (p>0.05).
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