Comparative study on milt quality features of different finfish species

Abstract

The aim of this research was to study the main sperm characteristics of three different finfish species. Twenty-one gilthead sea bream (Sparus aurata), 20 brown trout (Salmo trutta, morpha fario) and 15 rainbow trout (Oncorhynchus mykiss) male broodstocks, farmed under optimal conditions for each species and fed standard diets for broodstocks, were manually stripped. Brown trout yielded small amounts of sperm (4.5 vs 18.13 ml) that were very concentrated (≅ 8.5 × 109 vs 1.24 × 109 Szoa/ml) with respect to the other species. The duration of spermatozoan motility for gilthead sea bream sperm was significantly longer (almost 50 min), in comparison to the one-minute motility of Salmonids. Single fatty acids of brown trout sperm were higher than in the other two species for almost all detected fatty acids. In particular, eicosapentaenoic acid (EPA) was at least three times more concentrated in brown trout than in rainbow trout or gilthead sea bream sperm (1238.3 μg/g vs 305.6 and 333.3 μg/g, respectively; P < 0.01). Saturated, polyunsaturated and total unsaturated fatty acid classes were significantly higher in brown trout sperm than in the other two species - almost double with respect to gilthead sea bream sperm and more than double in comparison to RT sperm (P < 0.01).