Morphological traits and body condition parameters in prejuveniles of Mugil liza (Actinopterygii; Fam. Mugilidae) upon different postprandial times and refeeding

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

Conferencia; VII Conferencia Latinoamericana sobre Cultivo de Peces Nativos, ANAIS; 2022

ORGANIZADORES EQUIPO ORGANIZADOR RONALD KENNEDY LUZ GISELE CRISTINA FAVERO CINTIA LABUSSIÈRE NAKAYAMA

To determine the dynamics of morphological traits and body condition parameters at different times of food deprivation and after refeeding allows to establish the transition from feeding to fasting and the potential reversible recovery. Members of the family Mugilidae, generally known as mullets are cultured in many regions of the world. In Argentina the southern population of Mugil liza supports a small-scale fishery. M. liza is of great economical importance and of marked potential for aquaculture. Determinations of morphological parameters, such as total length, total mass, relative intestine length and hepatosomatic index enable to understand how postprandial effects impact on the organs morphology and physical condition. The aim of this work was to analyze the total mass, relative intestine length and hepatosomatic index as parameters of physical conditions at different times after feeding and after refeeding in prejuveniles of M. liza. Prejuveniles were collected (Total length: 50.5 ±5.1 mm, total weight: 42.1±4.3g) after recruitment into Mar Chiquita Coastal Lagoon, Argentina. The animals were maintained in aquarium water aerated and filtered (170L; 18 psu 20°C) and fed twice a day (TetraMin food) ad libitum. Determinations were done immediately (t0) and at 24, 72, 144 and 240h after feeding. At 240h, fish (were re-fed and the corresponding determinations were done after 72h. We determined total mass (TM), relative intestine length (RIL) ((intestine length/ standard length) x 100) and hepatosomatic index (HSI) ((liver weight/ total mass) x 100). After feeding, a decrease occurred in TM (144h, 25%) and RIL (144h, 23%) which could be linked to the fasting time point after refeeding TM and RIL were recovered. HSI did not change. The decrease of the RIL at 144 h along with the concomitant decrease in TM points out that this time of food restriction compromises the body condition of prejuveniles of M. liza. However, since no mortality occurs, underlying adjustments would allow survival. The increase of TM after 72 h of refeeding suggests the existence of underlying adjustments leading to recovery of body condition. The increase after refeeding of the RIL points out the occurrence of reversible integrated responses at different levels (e.g. morphological, biochemical). Our results represent a contribution that increases knowledge for improvement of aquaculture of prejuveniles of M. liza in particular, and of Mugilidae in general.