Effect of planting density on the results of growing in artificial conditions for Australian red-clawed crayfish with immobilized claws

Results of experimental growing of Australian red-clawed crayfish with immobilized dactylopodites (movable fingers) of claws are considered. Effects of planting density on body size and weight gains, duration of intermolting intervals, number of completed moults, and survival of crayfish were evaluated in three sections of aquarium with the same bottom area but different density, as 150, 255 and 350 ind./m 2 . At the end of the experiment (120 days), 75 ind./m 2 had survived in the first section (50.0 %), 102 ind./m 2 (40.0 %) in the second section, and 114 ind./m 2 (37.5 %) in the third section. Crayfish in the first section were less aggressive towards their neighbors, less stressed, and their mortality during molting was lower than in the other sections (35 %). In the intermolting period, the crayfish mortality was approximately equal in all sections (15.0–17.5 %). Effect of the dactylopodites immobilization for reducing aggression and cannibalism of redclaws during their growing in artificial conditions is discussed.