METABOLIC RESPONSES TO TROPHIC HABITS OF RAMNOGASTER ARCUATA

BLASINA, GABRIELA; ANA CAROLINA RONDA; MOLINA,JUAN MANUEL; ANDREA LOPEZ CAZORLA

Congreso; XVIII Congreso Latinoamericano de Ciencias del Mar COLACMAR 2019; 2019

Trophic habits of fish condition their wellbeing and different types of diets can producedifferent effects on their metabolic responses. Under hypothesis that different metabolicresponses will be found according to the trophic habits, we aim to determine thepossible effects of diet variations on the metabolism of the clupeid Ramnogasterarcuata. To cover the environments where the specie inhabiting, two sites wereselected in Bahía Blanca Estuary (BBE) and in the adjacent coastal zone (ACZ). A totalof 142 individuals were caught in BBE and 35 in the ACZ. Fish, between 1 and 2 yearsold, were chosen and analyzed according to its total length (Lopez Cazorla andSidorkewicj, 2009). Fulton´s condition index (K) and the diet composition weredetermined. The liver was extracted and lipid peroxidation, according to thethiobarbituric acid reactive substances (TBARs) method, protein content, and metabolic enzymes activities (Aspartate aminotransferase?AST and Alanine aminotransferase? ALT) were determined. We performed correlation analyses between parameters that presented variation among sites. Condition index, trophic ecology (including feeding activity and diet composition) and liver metabolism (ALT/AST activity and TBARS levels) were significantly different between BBE and ACZ. Consumption of mysids was positively correlated with ALT and negatively correlated with TBARs; while consumption of ostracods showed a negative correlation with ALT. Activities of ALT and AST correlated positively each other, indicating that if one of these enzymes is activated or inhibited, the other shows the same pattern. Moreover, ALT/AST activities positively correlated with K while a negative correlation between K and TBARs was observed (Figure). Our results indicate that diet composition has a strong influence in body condition metrics, as well as in the enzymatic activity. Biologic and metabolic responses observed in R. arcuata would change according to different food quality or food availability consumed in BBE and ACZ.