در زمان شروع تغذيه فعال ACIPENSER PERSICUS رفتار لارو و وضعيت ملانين پروپكادر روده لاروتاسماهي ايراني

Larval behaviour and melanin plug status in the spiral intestine of Persian Sturgeon (Acipenser persicus) larvae in the timing of initial feeding

Larval behaviour and melanin plug status in spiral intestine in the timing of first feeding (9, 10, 11, 12 and 13 days post hatch) with a live food (anemia naupli) on Persian Sturgeon at 17.7 ± 0.8 and 18.1 ± 0.4 °C was examined. The Study of larval behaviour exhibits that most of larvae become negative photo taxis and exhibit benthic behavior from 5 and 6 days post hatching at 18.1 ± 0.4 and 17.7 ± 0.8 °C, respectively; and from 10 and 13 day post hatching, most and all larvae come out of bentic state, and swim on surface and column water. Daily observations of digestion system exhibited when sufficient and suitable food is provided to larvae from the timing of initial feeding, although larvae have melanin plug in spiral intestine, they can capture and eat live food. Thus, expulsion of melanin plug cannot really be used to determine the time of active feeding.