Substrate preferences of juvenile, hatchery-reared lake sturgeon, Acipenser
fulvescens, from a Wisconsin population were examined relative to water te
mperature and velocity, fish size and time of day. Given the choice of a sa
nd, gravel, rock or smooth plastic bottom, all sturgeon were strongly attra
cted to the sand substrate. Water temperature did not affect substrate pref
erence, however small sturgeon (13.5 cm mean FL) acclimated to 19 degrees C
were more active than those tested in 6 degrees C water. Small sturgeon, u
nder all conditions, were less sedentary in the early morning and late even
ing hours than during the daytime. Preference of small sturgeon for sand wa
s slightly stronger when a current of 5 cm sec(-1) was present. Substrate p
reference of larger sturgeon (24.3 cm mean FL) was not affected by any of t
he parameters examined. In general, hatchery-reared lake sturgeon showed si
milar behaviors (with respect to substrate selection) as those previously d
escribed for the same population in the wild, making it possible that subst
rate preferences have a genetic component and likely that hatchery rearing
does not alter instinctive behavior.