Occurrence of Polyprion americanus under floating objects in western Mediterranean oceanic waters, inference from stomach contents analysis

Abstract

Catches of 11 juvenile specimens of Polyprion americanus (Osteichthyes: Polyprionidae) are reported under fish aggregation devices (FADs) in waters off Mallorca (western Mediterranean). Sampling was carried out fortnightly by surrounding artificial FADs with a purse seine from April 1995 till February 1997. Juveniles were present from June–August. Specimens were mostly solitary during the period of association to the FADs, with a length interval of 25.8 and 34.2 cm total length. The trophic spectrum was analysed to explain a possible food link with the FAD. The diet of Polyprion was mainly based on juvenile fish Trachurus and the eunestonic isopod Idotea metallica that were associated with the objects providing evidence for a trophic relation to the artificial structures.