Effects of the starvation on glycogen, lipids and proteins content in juveniles of the red claw crayfish Cherax quadricarinatus

CALVO, NS; CASTILLO DÍAZ, F; CORTÉS-JACINTO, E; LÓPEZ GRECO, LS

San José

Congreso; Sustainable Aquaculture at the upcoming Summer Meeting of The Crustacean Society (TCS) jointly organized with the Latin American Association of Carcinology (ALCARCINUS).; 2013

The Crustacean Society

The ability to withstand and recover from periods of nutritional stress is an important adaptation for survival of any organism and mainly in freshwater habitats. Point-of-no-return (PNR) is a threshold time at which initially starved animals have lost their capability to recover from nutritional stress, even if they are later fed ad libitum. The aim of this study is to describe the patterns of use of nutrient reserves nearby the PNR on Cherax quadricarinatus juveniles. In the two experiments done, juveniles were assigned to one of two groups: continuously fed (C) and continuously starved (S) juveniles. Juvenile samples from each group were taken at days that correspond to PNR25 and PNR50. The samples were weighted, lyophilized and then, glycogen, total lipids and protein concentrations were estimated. In earlier-juveniles experiment 800 individuals (14.8±0.18mg) were located on 16 aquaria and the samples were taken on days 8 and 9. In later-juveniles experiment 80 individuals (0.87±0.11g) were located on 16 aquaria and the samples were taken on days 40 and 50. Throughout both experiments, dry weight, total lipids and glycogen measured of S were lower than those of C. The protein content on early juveniles was similar between S and C along the experiments. However, on later-juvenile experiment, protein level of S was similar to C on day 40 but lower on day 50. The results suggested that during starvation, juveniles of Cherax quadricarinatus use lipids and carbohydrate as main energy source. Only nearby the PNR50, protein become a metabolic substrate on later juveniles.