Seasonal Variability in Trypsin and α-amylase Activities Caused by the Molting Cycle and Feeding Habits of Juvenile Pink Shrimp Farfantepenaeus duorarum (Burkenroad, 1939)

Abstract

ABSTRACT In view of the relationship between shifts in diet composition and the activity of digestive enzymes in penaeid shrimp, the present study focused on the analysis of digestive trypsin and α-amylase activities of wild Farfantepenaeus duorarum (Burkenroad, 1939) juveniles and their changes in phenotypic expression, during the molt cycle as endogenous factor and their changes due to different feeding regimes (exogenous factor) in relation with δ13C and δ15N isotopic signature as an index of food assimilation induced by the seasonal availability of food items in the nursery area. Wild juveniles of F. duorarum were captured from April 2007 to February 2008, in the Celestun coastal lagoon, Yucatan, Mexico. Samplings were carried out considering all quarters of the lunar cycle and in each of the recognized seasons for this region: dry, rainy, and the Nortes (North Wind). Copepods and amphipods were the main source of food for juveniles of F. duorarum. Values of δ13C in the muscular tissue were near -20‰ ...