Rearing of coregonid larvae with live and artificial diets.

概要

論文の詳細を見る
Results of the experiments leading to successful rearing of larvae of whitefish Coregonus lavaretus and peled C. peled aze presented. Live Artemia nauplii as first food for coregonids was compared with dry pelleted diets based on yeast and freeze-dried liver. In separate trials, mortality of fasting larvae and “point of no return” (PNR) were determined. Data from labora-tory studies on larval feeding behavior on live Artemia, rate of successful feeding and satiation time, are also presented. In both growth trials the final individual weight of fish fed live Artemia was significantly higher than fish fed dry diets. Growth and survival of whitefish was better than that of peled on the best dry diets after 34 days of rearing. PNR determined as the time of 50% survival of fish amounted to 11.1 and 13.2 days at 16.2°C for white fish and paled larvae, respectively. The intake of Artemia nauplii and the percent of successful attacks of prey increased with whitefish larvae length. Whitefish larvae decreased feeding intensity after initial 2 min of feeding and maintained to feed at the same intensity up to 10 min. First feeding larvae of peled consumed more prey and proportion of larvae feeding was higher at 15.6°C than at 8.7°C when fasted for 10 days. Larvae fasted longer than time of PNR decreased feeding rate, and 90 min of food presence was not sufficient for all larvae to commence feeding.