| Remarks |
An oceanic species that is lower epipelagic to mesopelagic and bathyal, and ranges in tropical and temperate waters of the 3 major oceans and the Mediterranean Sea. Undergoes diel vertical migration and consequently is able to regulate its bioluminescent counterillumination. As a nerito-oceanic species, occurs in association with seamounts and submarine ridges. Age and growth studies based on statolith analysis indicate a strong sexual dimorphism: males live about 1 year, females begin to mature at 1 year and spawn at about 1.5 years. Following ontogenetic descent into bathyal waters, at least to 680 m, growth rate decreases to lowest known values for squids. Relative fecundity is 200,000 to 800,000 ova, 2.6 to 1.91 mm diameter, of which 60 to 65% are spawned. Hatching occurs throughout the year; peaks November to March. Sexually mature males captured in southern African waters had nidamental glands in addition to the fully developed male reproductive system. Intersexual males were significantly larger than normal males. Preyed upon by swordfish, Xiphias gladius, lancetfish, tunas, blue shark, oceanic seabirds, Antarctic fulmar and odontocete cetaceans, e.g. sperm whales, pygmy and dwarf sperm whales, long-finned pilot whale (Ref. 97142). |