Illex

Illex is a genus of squid in the family Ommastrephidae, within the order Teuthida. It includes several species of pelagic squid found in temperate and subtropical seas around the world. The best-known members are Illex illecebrosus, the shortfin squid of the Northwest Atlantic, and Illex argentinus, the Argentine shortfin squid of the southwestern Atlantic; other valid species occur in the Atlantic, Indian, and Pacific Oceans.

Ecology and biology: Members of Illex are fast, open-water predators that inhabit the pelagic zone and undertake diel vertical migrations, occupying surface waters at night and deeper waters by day. They feed on small fish, crustaceans, and other invertebrates. Reproduction occurs in warmer surface or near-surface waters, where females lay gelatinous egg capsules that hatch into free-swimming paralarvae. Maturation tends to be rapid and lifespans are relatively short, allowing populations to respond quickly to environmental changes.

Fisheries and human use: Illex species are among the most commercially exploited cephalopods in several regions. Illex argentinus supports large regional fisheries in the southwestern Atlantic, while Illex illecebrosus supports fisheries in the Northwest Atlantic. Other Illex species are harvested in smaller quantities or as bycatch. Processed products enter global markets for direct human consumption and as inputs for aquaculture and other industries.

Conservation and management: Like other cephalopods, Illex stocks are influenced by climate variability, ocean productivity, and fishing pressure. Regional stock assessments and management measures aim to prevent overfishing and to maintain sustainable catch levels, adjusting to changing environmental conditions and market demands.