Growth, fatty acid composition, and reproductive parameters of diploid and triploid yellowtail tetra Astyanax altiparanae

The aim of this study was to evaluate the growth, carcass yield, fatty acid composition, and reproductive parameters of diploid and triploid Astyanax altiparanae. Triploidization was induced by heat shock (40 degrees C for 2 min) 2 min after fertilization. Fish were reared for 175 days from fertilization. Triploid females showed lower proportion of saturated and poly-unsaturated fatty acids and higher amount ofmono-unsaturated fatty acids than diploids. They were sterile, with immature gonads, and showed higher carcass yield than diploid females, which exhibited higher gonadosomatic indices. Triploid and diploid males showed similar gonad morphology, although diploid males produced greater numbers of spermatozoa. All males exhibited the secondary sex characteristic of spines in the pelvic and anal fins. Fatty acid composition and growth were similar in triploid and diploid males. Triploidy did not ensure sterility in males, but triploid females were sterile and had increased carcass yield, and may be used in aquaculture to increase the production of A. altiparanae. Statement of relevance: To our knowledge, this is the first study addressing the effect of triploid induction on growth parameters of a neotropical species. The important results for carcass yield and sterility in female triploid will improve the production of A. altiparane, as this species is being used as live-bait for sport fishing and direct consumption. (C) 2017 Elsevier B.V. All rights reserved.