Oxygen consumption of Limnomysis benedeni Czerniavsky, 1882 (Crustacea: Mysidacea), a Pontocaspian species in Lake Balaton, Hungary

Limnomysis benedeni Czern. was artificially introduced into Lake Balaton in 1950 in order to increase the food source of young (1+, 2+) pike perch (Stizostedion lucioperca L.). L. benedeni successfully adapted to the alkaline water of the lake (pH = 8.4–8.8) and recently is a frequent crustacean of the littoral zone. We determined the relationship between body size and dry body mass and measured the oxygen consumption of L. benedeni at 0, 5, 10, 15, 20 and 23 °C, and at different pH (5.4 and 8.4). We obtained a significant relationship between the body length and the dry body mass of y=0.0101e0.8592x. The specific oxygen consumption decreased with the body length according to a power function. Treatment with low pH caused significant increase of the oxygen consumption of the animals at 23 °C, which reflects some acid-stress and enhanced energy demand. Below 23 °C only juveniles (smaller than 5 mm in size) consumed more oxygen at pH 5.4 than at pH 8.4. The oxygen consumption of the animals ranged from 1 to 30 μg O2 mg-1 dry mass h-1 depending on the body length and the temperature. The functional relationships of oxygen consumption obtained make it further possible to estimate the organic carbon flux of the populations of L. benedeni in Lake Balaton.