Turkish Journal of Fisheries and Aquatic Sciences
2012, Vol 12, Num, 4 (Pages: 947-950)
A Preliminary Study on Protease Activity of the Northern Pike (Esox lucius L. 1758) Larvae
2 Szent Istvan University, Department of Fish Culture, Gödöllö, Hungary DOI : 10.4194/1303-2712-v12_4_22 Viewed : 4259 - Downloaded : 2952 The proteolitic activity of northern pike prelarvae was measured in yolk sac stage to reveal the critical first feeding time at relatively high incubation temperature. The differences observed among protease activities of larvae from day after hatching (DAH) 0 to 12 were statistically significant (P<0.05). Protease activities of larvae remained slightly increased from DAH 0 to DAH 5. A sudden raise in protease activities of larvae were observed from the DAH 6 to the DAH 8. Moreover, the conspicuous increase in protease activities of pike larvae was determined at the DAH 8 (595.22±9.07 U/mg protein). All starving larvae died four days after yolk sac consumption. In conclusion, to prevent tissue breakdown, larvae should be fed immediately just after yolk sac absorption at the DAH 8 at 13°C under controlled conditions. Keywords : Pike, ontogeny of larvae, protease activity, yolk sac absorption, first feeding time