Larvicultura do Betta splendens: otimizando a produção na fase inicial

Abstract

The present study aimed to test and evaluate the effects of different diets on the growth and survival of fry of the species Betta splendens. The experiment lasted 24 days, not including preparation time. 420 three-day-old betta fry underwent an adaptation that lasted 9 days, being fed only with brine shrimp nauplii to promote mouth opening and instigate their predatory behavior. Once this was done, they were distributed within 42 aquariums (approximately 2, 5L each), each with 10 fry. In total there were 14 treatments, 7 foods administered in 2 feeding frequencies: Artemia nauplius once a day (Ct1x), Artemia nauplius twice a day (Ct2x), Enchytreas once a day (Enq1x), Enchytreas twice a day (Enq2x), Pickled brine shrimp nauplius once a day (NACs1x), Pickled brine shrimp nauplius twice a day (NACs2x), Pickled brine shrimp cyst once a day (CACs1x), Pickled brine shrimp cyst twice per day (CACs2x), Microworm once per day (Mv1x), Microworm twice per day (Mv2x), frozen Artemia nauplius once per day (NACg1x), frozen Artemia nauplius twice per day (NACg2x), Pickled Copepod once a day (CCs1x) and Pickled Copepod twice a day (CCs2x). Food was offered in abundance and according to the food frequency established during the 15-day experimental period. To maintain the quality of the water, siphoning was done one hour after each meal, in order to remove leftovers so that it did not turn into ammonia. The chemical and physical parameters of the water were not measured, but all water used in the experiment was at room temperature. Artemia nauplii and enchytreas showed the best results when fed twice a day, both for final length and survival, treatments fed once a day with Artemia nauplii, enchytreas and microworms showed no difference (P>0 .05) in survival for the same foods given twice a day. Experimental units treated with pickled copepods (CCs) had total mortality at both feeding frequencies. We conclude that enchytrea can be used as a substitute for brine shrimp nauplius in the initial phase of Betta splendens, being able to offer similar nutritional benefits and at the same time reduce larviculture costs.