Sex reversal, growth, and survival in the swordtail fish Xiphophorus helleri (Cyprinodontiformes: Poeciliidae) under laboratory conditions

Abstract

The fish Xiphophorus helleri is a commercially important species. Here we analyze several cultivation variables. We studied them for 120 days in 10-gallon aquaria without aeration; 1 fry per liter, the temperature varied between 26,3 and 26,9 ° C. The pH ranged from 8,1 to 8,8 and the oxygen concentration from 6,2 to 6,6mg / L. Api-aba balanced fodd with 25% protein was used, three hormones were added: 1) Sten 2) Primoteston and 3) Sostenon 250. Sex reversal was 84,3%, 91,4% and 93,3% correspondingly. A fish with treatment 1 gained an average of 0,55g and total length of 5,4cm, with treatment 2: 0,59g and 5cm; and with treatment 3: 0,55g and 4,1cm. The 8th fortnight survival was 80%, 90% and 75% correspondingly; these differences are not statistically significant. The three treatments gave the expected results of sex reversal, growth and survival. KEY WORDS Sexual revertion, animal feed, population density, hormone supply, aquaria without aeration