Effect of attractant and food availability on digestive enzymes in the redclaw crayfish Cherax quadricarinatus (Parastacidae).

HERNÁN J. SACRISTÁN; HÉCTOR NOLASCO-SORIA; LAURA S. LÓPEZ GRECO.

San José

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

The Crustacean Society

ver página 160 del CD de resúmenesFood is one of the most important costs in aquaculture so it?s necessary to improve feeding strategies.Chemoreception plays a significant role in feeding behavior, thus it is logical to assume that inclusionof attractants/feeding stimulants in pellets will improve consumption time avoiding nutrients losses.This study analyzed the effect of the inclusion of squid meal (attractant) on feeding behavior, and theeffect of food availability on digestive enzymes in juveniles of C. quadricarinatus. The composition ofbase feed (BF) was: 37.98% of protein, 6.05% of lipid and 16.05% of ash and the attractant concentrationranged from 0 to 10%. Behavior of 20 juveniles per treatment was observed in a glass aquariumdivided into three compartments, to evaluate which was their first choice (attractant or not attractant)and the time of residence in each compartment. Each trial was 10 recorded for minutes. The resultsshowed that the inclusion of squid meal did not act as an attractant for this species. The effect offood availability on digestive enzymes after two days without food was assessed using the followingtreatments: no BF; available BF (phage-stimulated) and present but not available BF. The activity ofproteases, lipases and amylases at 5, 10, 30, 60 and 120 minutes post feeding was recorded. Theresults indicated that at the assayed conditions food availability did not modify the levels of digestiveenzymes. These results would be reinforcing the concept that C. quadricarinatus is an omnivorousopportunistic species from fluctuating habitats adapted for some periods of food restriction.MINCYT-CONACYT MX/09/07. BID PICT 01187. UBACYT 2011-2014 (20020100100003)