The twoband cichlid Vieja bifasciata is an indigenous fish species from the tropical areas of Central America. This specie is considered as candidate for aquaculture due the high demand for traditional cuisine reaching 5 US/kg in regional market, and ornamental production is considered promissory for international sales due to coloration. Twoband cichlid larvae production is feasible using experimental RAS using commercial diets, and actually fry is mainly destinated for restocking traditional fishing areas. In the wild, adults weight commonly show differences by sex like another cichlid species, but absence of data on age do not allows to define a differential grow hypothesis. In order to determine if Vieja monosexual population show differential growth, an experimental protocol for fry production and masculinization was developed.
Fourteen, one year old Viaja bisfaciata adults (180-460 g) reared in laboratory were stocked in 1.7 m3 tanks for larvae production during reproductive season (April). Adults were fed twice a day using commercial diet and water quality maintained by weekly 5% water renewal. A triplicated masculinization trial was conducted using first feeding larvae. Larvae were fed by 28, 45 and 60 days using a diet containing 60 mg/kg of the steroid (17α-MT), and a control treatment. At the end of the treatment, fry was transferred to a RAS for grow-out for 120 days and masculinization evaluation.
Spawning’s occur the second day of adult stocking, but cannibalistic behavior is commonly observed and repeated fight. Larvae production ranged from 450 to 1700 larvae by spawn. First feeding occur 5-6 days post hatching at 26-28°C. Results on masculinization indicate that males tend to increasing according to treatment time (P=0.00). Sex proportion data indicate a minimal time of 45 days using oral administration of MT is required to increase male proportion production in the twoband cichlid. New experimental protocol is necessary to improve result on male production.