Twilight activity patterns and angling vulnerability of yellowmouth barracuda (Sphyraena viridensisCuvier, 1829), a range‐expanding thermophilic fish

Abstract

Among the thermophilic fishes that have become established in the northwestern Mediterranean as a consequence of sea warming, the yellowmouth barracuda (Sphyraena viridensis Cuvier, 1829) appears to be one of the most successful and abundant in the coastal rocky environment, having increasingly become the object of recreational and commercial exploitation in the study area. Lure-fishing sessions were carried out from May 2016 to November 2018 in the Catalan Sea (NE Spain) at dawn and dusk, with the aim of providing new insight into the behavioural, spatial and feeding ecology and vulnerability to angling of this poorly known species. Generalized mixed-effects linear models showed that S. viridensis is a crepuscular inshore dweller, whose vulnerability to angling is significantly influenced by solar and lunar light intensities, being highest in the pre-spawn and spawning periods. Asymmetries between dawn and dusk activity patterns were detected, evidently related to a drop in aggressiveness at dusk following the spawning period. The simple study design adopted may be applied to other contexts, aiming to the recognition of several levels of fish vulnerability to angling.

Angler and environmental influences on walleye Sander vitreus and muskellunge Esox masquinongy angler catch in Escanaba Lake, Wisconsin 2003–2015

“…Angler trip success and catch rates are dependent upon a fishes’ vulnerability to angling gear [ 10 ] and often decline with increased fishing effort [ 11 , 12 ]. Fish angling vulnerability is described as a function of mechanisms that are influenced by the internal state of the fish, bait encounter probability, and selectivity of angling gear [ 10 , 13 ]. Angling vulnerability and catchability of fish is influenced by angler-specific attributes [ 14 ] such as bait choice [ 15 , 16 ], lure size [ 17 – 19 ] and use of a guide [ 16 ].…”