Engraulis encrasicolus larvae from two different environmental spawning areas of the Central Mediterranean Sea: first data on amino acid profiles and biochemical evaluations

F Falco,M Barra,G Wu,M Dioguardi,P Stincone,A Cuttitta,M Torri,A Bonanno,M Cammarata

doi:10.1080/24750263.2020.1823493

Abstract

Early life stages of marine fish populations may be strongly affected by environmental factors. Changes in the physical environment or the availability of food resources could lead to stress-related physiological responses affecting larval fitness, growth and survival. In the present study, we determined, for the first time, amino acid composition (AAC), lipid, and carbohydrate content, as well as alkaline phosphatase and peroxidase activities in larvae from the European anchovy Engraulis encrasicolus. Fishes were caught in two different spawning areas of the Strait of Sicily, characterized by different environmental conditions, including a coastal upwelling with a lower temperature (Adventure Bank; 20.22 ± 0.38°C) and a thermohaline front with a higher temperature (Maltese Bank 23.10 ± 0.25°C). The results showed that the two groups of larvae, in their early life, had similar nutritional status. However, compared with the samples from the Maltese Bank, the specimens collected in the Adventure Bank area exhibited higher alkaline phosphatase activity, lower concentrations of aspartate plus asparagine, threonine, and arginine but a higher concentration of leucine, highlighting different patterns of amino acid metabolism. Collectively, these results indicated that AAC analysis could represent an additional valid tool to evaluate the link between physiological responses and environmental conditions at early life stages.

Highlights

Aquatic organisms react to changes in environmental conditions through adaptive mechanisms that allow them to cope with real or perceived environmental variations to maintain their normal physiological state
We proposed that the amino acid composition (AAC), nutrient content, and the density pattern of pelagic and mesopelagic fish (Cuttitta et al 2006; Bonanno et al 2013) are affected by the ocea nographic phenomenon in the Sicily channel
Our study investigates the effect of environmentalrelated stressors on the physiology of anchovy larvae through the AAC analysis

Summary

Introduction

Aquatic organisms react to changes in environmental conditions through adaptive mechanisms that allow them to cope with real or perceived environmental variations to maintain their normal physiological state. Salinity, and hydrody namic conditions beyond naturally occurring ranges as well as food limitations are stressors (i.e., conditions threatening or disturbing the dynamic equilibrium of organisms) that strongly affect metabolic and bio chemical processes and induce stress-related responses (Somero & Hochachka 1976; Somero et al 1983). In this context, the physical and chemical characteristics of the marine environment, as well as its intrinsic varia bility, present significant challenges to tissue proteins, whose structures and biological activities are depen dent on non-covalent (“weak”) chemical bonds which are readily disrupted by changes in temperature, hydrostatic pressure, and solute composition (Somero 2003). In addition to peptidebound amino acids, eyes contain free amino acids, including aspartate, asparagine, glutamate, glutamine, glycine, serine, proline, homocysteine, and taurine

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