Morphological and ecological notes on the swimming crab Achelous hastatus (Linnaeus, 1767) (Family: Portunidae), from Tenerife, Canary Islands (NE Atlantic)

Abstract

A voucher-backed adult male specimen of Achelous hastatus (Linnaeus, 1767) was collected on 6 August 2025 during a night dive at 6 m depth off Granadilla, Tenerife, Canary Islands. The specimen was subjected to comprehensive morphometric analysis and documented with high-resolution imagery under controlled laboratory conditions. Morphological features--including a broadly hexagonal carapace with nine anterolateral teeth (ninth markedly elongate), a four-lobed frontal margin, robust chelipeds with slender fingers, and a natatory fifth pereiopod--matched diagnostic descriptions from comparative literature. Field observations documented nocturnal foraging in association with a multi-individual feeding aggregation, scavenging on vertebrate remains. Aggregated occurrence data from the Ocean Biodiversity Information System (OBIS) and the Global Biodiversity Information Facility (GBIF) confirm the species widespread Atlantic-Mediterranean distribution, with Spain (including the Canary Islands) representing a primary stronghold. This record contributes high-resolution imagery, morphometric detail, and ecological context to the biogeographic dataset for A. hastatus in the Macaronesian region.