Combined effects of water temperature and daily food availability period on the growth and survival of tench (Tinca tinca ) larvae

Abstract

A 16-day experiment was designed to find the best combination of water temperature (27, 30, 33°C) and daily duration of food availability (12, 18, 24 h) for larval tench (Tinca tinca) growth and survival. Larvae with an initial mean size of 5.7 mm total length (TL) and 0.7 mg wet body weight (BW) were stocked at 15 L−1. Larvae were fed in excess with live Artemia nauplii with the period of food availability lasting 12, 18 or 24 h daily. The largest final larval size was recorded at 27 and 30°C in groups fed for 24 h a day (17.7 and 17.9 mm TL, 76.1 and 77.7 mg BW, respectively). The combination of the highest temperature and the longest daily food availability was the only set of conditions under which final larval survival was affected (95.4% survival; 98.7–99.9% under all other conditions). The combination of water temperature of about 28.6°C and continuous food availability is recommended as the optimum combination for rearing T. tinca larvae under controlled conditions. Providing continuous food supply to fish larvae under aquaculture conditions was also advantageous in helping to mitigate the effects of slower growth relative to developmental progress, which can occur at high water temperatures. However, should one wish to limit the daily feeding period to 12 h per day, the use of a water temperature between 27.4 and 27.9°C would be the best solution.