Arch. Pol. Fish.     Vol. 7     Fasc. 1            1999      p. 201-211

ACTIVITY OF DIGESTIVE ENZYMES IN SIBERIAN STURGEON JUVENILES (ACIPENSER BAERI BRANDT) – A PRELIMINARY STUDY

Krystyna Żółtowska1, Ryszard Kolman2, Elżbieta Łopieńska1, Halina Kolman1

1Faculty of Biology, Warmia and Masuria University in Olsztyn
2The Stanisław Sakowicz Inland Fisheries Institute in Olsztyn

ABSTRACT. The study was carried out on Siberian sturgeon fry and fingerlings at the age of 9-44 days post hatching (dph). Activities of proteolytic, lipolytic and amylolytic enzymes, and dicaccharidases were measured in the digestive tract extract. Only alkaline proteases were observed in 9 dph fish, and no lipolytic or amylolytic activity were found. After the first week of exogenous feeding (16 dph), high lypolitic and maltase activities were noted, as well as slight activity of acidic proteases, but no pepsin. Pepsin activity was observed for the first time on 44 dph. Amylolytic activity increased gradually between 3 and 6 weeks post hatching. Activity of dicaccharidases: maltase and trehalase reached the maximum on 30 dph. No lactase or saccharase were observed.

Key words: Acipenser baeri, FRY FEEDING, BIOCHEMICAL STUDY, DIGESTIVE ENZYMES, ONTOGENESIS.