Comparison of oxygen consumption and ammonia excretion by siberian sturgeon (Acipenser baeri Brandt) and its hybrid with green sturgeon (Acipenser medirostris Ayres)

Abstract

Studies were carried out on diurnal changes of oxygen consumption and ammonia excretion by Siberian sturgeon (Acipenser baeri Brandt) and its hybrid with green sturgeon (Acipenser medirostris Ayres). Different behaviour of Siberian sturgeon and the hybrid resulted in different diurnal pattern of the two metabolic indices. In case of the hybrid oxygen consumption and ammonia excretion were higher at night than during daytime (12-36% and 10-27% respectively). In Siberian sturgeon the values of the two indices were similar over the 24 h period. Maximum oxygen consumption by the hybrid was observed at night, from 10 p.m. to 2 a.m., and the highest ammonia excretion – early in the morning, from 6 to 10 a. m.