Analyses of body condition and digestive/metabolic parameters of Odontesthes argentinensis (Atherinopsidae) from Mar Chiquita Coastal Lagoon (Argentina) during different phases of ovarian development

Abstract

Abstract This study analyses body condition and digestive/metabolic parameters of Odontesthesargentinensis from Mar Chiquita Coastal Lagoon (MChCL) during different ovary maturity phases (II: developing; III: spawning capable; IIIas: actively spawning subphase). Silverside individuals in phases II and III maintained their body condition, while it improved in actively spawning subphase. Total weight and Fulton’s condition factor increase in 70% and 50%, respectively. No changes were observed during the ovary maturation phases in hepatosomatic index and intestinal coefficient. Maltase activity in the intestine remained unchanged, while Aminopeptidase-N was higher, about 300%, in the spawning capable phase (III). Alkaline phosphatase in the intestine was unchanged pointing out the maintenance of intestinal homeostasis. Liver glycogen concentration decreased, about 40%, in the actively spawning subphase (IIIas), while muscle glycogen abruptly decreased in phase III and recovered in subphase IIIas. In intestinal fat, triglycerides concentration was lower 70% in subphase IIIas, while no changes occurred in liver and muscle. Muscle protein concentration decreased about 50% in actively spawning subphase. The findings shed light on the remarkable adaptability of this population of O. argentinensis from MChCL to support its gonadal maturation and active spawning maintaining and even improving its physical condition.

Keywords

• Digestive enzymes
• Energy reserves
• Euryhaline fishes
• Reproductive ecology
• Silverside