Effects of starvation on digestive enzymatic activities in the red claw crayfish Cherax quadricarinatus juveniles.

NATALIA S. CALVO; HERNÁN J. SACRISTÁN; LAURA S. LÓPEZ GRECO.

San José

Congreso; TCS-ALCARCINUS Summer Meeting, Costa Rica 2013; 2013

The Crustacean Society

ver CD DEL CONGRESO, PAG 164The hepatopancreas is considered the major storage organ in decapod crustaceans. It mainlyaccumulates lipids, glycogen and protein. Starving conditions cause alterations both in the amount ofreserves and in the digestive enzymatic activities. The point-of-no-return (PNR) is a threshold time atwhich initially starved individuals have lost their capability to recover from nutritional stress, even ifthey are later fed ad libitum. The aim of this study is to describe the enzymatic activities during a longperiod of starvation to understand the pattern of use of reserves nearby PNR. A total of 90 juveniles(mean weight 1g) were randomly assigned to one of two groups. Control juveniles were continuouslyfed while treated juveniles were fed since day 50, until the end of the experiment (day 90). Fifteenjuveniles from each group were sacrificed at days 40, 50 and 90. Days 40 and 50 correspond toPNR25 and PNR50 , respectively. Protease, lipase and amylase activities of the hepatopancreas wereestimated. Lipase activity from treated juveniles was lower than that of control juveniles during thestarvation period, however, after the feeding period, activity was similar between groups. Amylaseand protease activities showed no significant differences between groups although protease activitytended to increase at day 50 and to diminish after the feeding period. Lipase activity suggests lipidsuse as the main energy source during long starvation period while protease increasing activity nearbyday 50 could be causing the observed structural disorganization of the hepatopancreas.BID PICT 01187. PIP 129. UBACYT 2011-2014 (20020100100003)