Phenotypic flexibility in juvenile flounder Paralichthys orbignyanus (Valenciennes, 1839): differential modulation of digestive enzymes and energy reserves in relation to diet

ALBANESI, CAMILA; RADONIC, MARIELA; LOPEZ, ANDREA; LOPEZ MAÑANES ALEJANDRA

Pan-American Journal of Aquatic Sciences

PanamJAS

Año: 2021 vol. 16 p. 79 - 89

1809-9009

The flounder Paralichthys orbignyanus is a flatfish of great ecological and economic importance that lives mainly in estuaries and coastal waters in Southwest Atlantic. Integrative studies on modulation of digestive enzymes and energy reserves along with growth upon differential proportions of key dietary substrates are lacking. We determined amylase, maltase, sucrase, trypsin, aminopeptidase-N (APN) and lipase activities in intestine and glycogen, triglycerides and proteins concentration in liver and muscle of juveniles fed with two diets (Diet 1; 35.5% carbohydrates, 41% proteins, 13.6% lipids; Diet 2; 41.8% carbohydrates, 46% proteins, 2.8% lipids). Juveniles fed with Diet 2 exhibited higher maltase, sucrase and trypsin activity (54%, 39% and 110%), lower triglycerides concentration in liver and muscle (65% and 14%), lower proteins content in liver (35%) and higher weight gain. Amylase, APN and lipase activity, glycogen and free glucose in liver and muscle and proteins in muscle were similar. The differential modulation of digestive enzymes and energy reserves suggest specific digestive and metabolic adjustments allowing growth upon diet with high carbohydrate and low lipids content. This work contributes to the knowledge of digestive and metabolic physiology of flatfishes which are of importance for the development of activities with economic impact in our region.