Understanding the early ontogenetic stages of Mugil liza (Mugilidae): morphological traits and digestive/metabolic profile of pre‐juveniles after recruitment

ALBANESI,C.; GONZALEZ CASTRO, M. *AMBOS AUTORES CONTRIBUYERON DE IGUALMENTE A ESTE TRABAJO; LÓPEZ MAÑANES, A.A:.*AMBOS AUTORES CONTRIBUYERON DE IGUALMENTE A ESTE TRABAJO

JOURNAL OF FISH BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2021 vol. 98 p. 643 - 654

0022-1112

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.Key words: Flatfish, digestive flexibility, metabolic flexibility, dietary substrates.