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

RADONIC, M; ALBANESI,C.; LÓPEZ MAÑANES A.; LOPEZ,A

Pan-American Journal of Aquatic Sciences

Pablo Muniz M.

Año: 2021 vol. 16 p. 79 - 89

1809-9009

Abstract. The flounder Paralichthys orbignyanus is a flatfish of great ecological and economicimportance that lives mainly in estuaries and coastal waters in Southwest Atlantic. Integrativestudies on modulation of digestive enzymes and energy reserves along with growth upondifferential 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 (Diet1; 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 trypsinactivity (54%, 39% and 110%), lower triglycerides concentration in liver and muscle (65% and14%), lower proteins content in liver (35%) and higher weight gain. Amylase, APN and lipaseactivity, glycogen and free glucose in liver and muscle and proteins in muscle were similar. Thedifferential modulation of digestive enzymes and energy reserves suggest specific digestive andmetabolic adjustments allowing growth upon diet with high carbohydrate and low lipidscontent. This work contributes to the knowledge of digestive and metabolic physiology offlatfishes which are of importance for the development of activities with economic impact inour region.