Diet variability in European anchovy: a comparative analysis between larval populations of the inner Bay of Biscay and the NW Mediterranean

Abstract

Feeding is critical for larval survival and it becomes a determining factor in the annual recruitment in species such as European anchovy Engraulis encrasicolus. Additionally, since differences in the plankton community may affect the larval feeding patterns, an interregional comparative study may contribute to understand these patterns concerning larval development and environmental features. The diet, feeding pattern and prey selectivity in relation to the ontogeny of the larval anchovy in the Cantabrian Sea (inner Bay of Biscay) and the Catalan Sea (NW Mediterranean) were compared in this study. Larvae fed preferentially on copepod eggs, nauplii and calanoid postnauplii, selecting them actively. Larval diet was similar before notochord flexion in the two areas. Nonetheless, for larvae of comparable size, prey preferences skewed towards small preys in the Cantabrian Sea, and towards large preys in the Catalan Sea. Differences appeared in the middle-sized larvae (6.5-9 mm) due to prey size and type. Diet differences were attributable (a) to the ability of the Catalan Sea larvae to capture bigger preys at a smaller individual size; and (b) to differences in prey preferences and availability. Therefore, geographic variety in larval populations and food environment features may promote variability in the larval anchovy diet.