The Israeli Journal of Aquaculture - Bamidgeh 54(4), 2002, 145-156

PRODUCTION OF ANDROGENETIC NILE TILAPIA,
OREOCHROMIS NILOTICUS L.: OPTIMIZATION OF HEAT SHOCK
DURATION AND APPLICATION TIME TO INDUCE DIPLOIDY


Sedat Karayücel and Ismihan Karayücel*
Su Ürünleri Fakültesi, Ondokuzmayis Üniversitesi, 57000 Sinop, Turkey

David Penman and Brendan McAndrew
Institute of Aquaculture, University of Stirling, Scotland, FK9 4LA, UK

(Received 26.7.02, Accepted 10.9.02)

Key words: androgenesis,diploidy,tilapia

Abstract

Diploid androgenetic Nile tilapia, Oreochromis niloticus, were produced using 5 min UV irradiation at 150 W/cm and heat shock at 42.5°C for 3:30 min applied 25 min after fertilization. The survival rates to morula, pigmentation, hatching and yolk sac resorption stages were 42.844.73%, 10.692.24%, 2.030.60% and 0.070.07% (relative to controls), respectively. A significant female, but not male, effect on the survival was confirmed. Multilocus DNA finger-printing produced by hypervariable 33.15 DNA probe verified the all-paternal inheritance in the androgens. The sex ratio of the androgenetic tilapia was not significantly different from the expected ratio of 1:0 (male:female), indicating that O.niloticus has a monofactorial sex-determining mechanism with female homogamety and male heterogamety. This study confirmed that the YY genotype is viable and fertile in O.niloticus.

*Corresponding author. Tel.: +90-368-287-6265, fax: +90-368-286-6255, e-mail: ismihank@hotmail.com
home