METABOLIC RESPONSES TO TROPHIC HABITS OF RAMNOGASTER ARCUATA

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

Mar del Plata

Congreso; XVIII Congreso Latinoamericano de Ciencias del Mar-COLACMAR; 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 metabolicenzymes activities (Aspartate aminotransferase?AST and Alanine aminotransferase?ALT) were determined. We performed correlation analyses between parameters thatpresented variation among sites. Condition index, trophic ecology (including feedingactivity and diet composition) and liver metabolism (ALT/AST activity and TBARSlevels) were significantly different between BBE and ACZ. Consumption of mysids waspositively correlated with ALT and negatively correlated with TBARs; whileconsumption of ostracods showed a negative correlation with ALT. Activities of ALTand AST correlated positively each other, indicating that if one of these enzymes isactivated or inhibited, the other shows the same pattern. Moreover, ALT/AST activitiespositively correlated with K while a negative correlation between K and TBARs wasobserved (Figure). Our results indicate that diet composition has a strong influence inbody condition metrics, as well as in the enzymatic activity. Biologic and metabolicresponses observed in R. arcuata would change according to different food quality orfood availability consumed in BBE and ACZ.