Diversification of Aquacultural Practices by Incorporation of Native Species and
Implementation of Alternative Sex Inversion Techniques
Appropriate Technology Research 3, 10ATR3
Final Report
Wilfrido M. Contreras-S‡nchez and Gabriel M‡rquez-Couturier
Laboratorio de Acuacultura
Universidad Ju‡rez Aut—noma de Tabasco
Villahermosa, Tabasco, Mexico
Grant W. Feist
Department of Fisheries and Wildlife
Oregon State University
Corvallis, Oregon, USA
Arlette Hern‡ndez-Franyutti
Laboratorio de Acuacultura
Universidad Ju‡rez Aut—noma de Tabasco
Villahermosa, Tabasco, Mexico
Carl B. Schreck
Biological Resources DivisionÑUS Geological Survey, Oregon Cooperative Fishery Research Unit
Department of Fisheries and Wildlife
Oregon State University
Corvallis, Oregon, USA
Guillermo Giannico
Department of Fisheries and Wildlife
Oregon State University
Corvallis, Oregon, USA
Graduate Student Researcher: Ulises Hern‡ndez-Vidal, UANL
Graduate Research Student: Candelario Bautista-Cruz, UJAT
Undergraduate Research Students: Gabriel Real-Ehuan (UJAT), Emil P. Ramon-L—pez (UJAT), Abigael Ch‡vez-MŽndez (UJAT), Milciades De la Cruz-Rodr’guez (UJAT), Sergio G—mez-Triano (UJAT), Mariela Frias-L—pez (UJAT)
Abstract
This study sought to determine whether administration of steroids via bioencapsulation into live food is an efficient method for sex inversion of carnivorous species of fish in aquaculture. This technique may offer an alternative for sex reversing such species because the larvae strongly prefer live food compared to artificial diets. To determine whether steroids could accumulate in Artemia, nauplii were immersed in solutions containing 2,500 mg L-1 of either estradiol (E2) or trenbolone acetate (TA). Steroids were dissolved in ethanol (1 mg ml-1) and then added to the water. Controls were immersed in water containing ethanol vehicle only. Each treatment consisted of three replicates. Water samples (50 ml) from glass jars containing Artemia nauplii were collected at 0, 2, 4, 6, 12, 16, 20, and 24 h. Nauplii were washed in nanopure water and dried, and samples were frozen (Ð20oC) and preserved until processed. All samples were extracted using ether, and the concentration of steroids were determined by radioimmunoassay (E2) or High Performance Liquid Chromatography HPLC (TA). Immediately after addition of steroids, nauplii contained > 1,500
