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BiologyWarmer-water distribution, within 15° of the Equator. Large adults sometimes kill themselves by swimming out of the water onto beaches; occurrence of such strandings may be linked to certain areas, seasons or months and often in spates. With a unique adaptation of self-amputation (autotomy) of the posterior part of the body past the vent which may involve only the caudal fin (or one to a few small adjacent vertebrae) or as far anterior as just before the abdomen; apparently occurs several times during its lifetime (serial autotomy) but do not damage any vital organs and are usually survived except in strandings. All records over 1.5 m long have bodies shortened by autotomy and may exhibit a healed-over stump or "terminus"; still, many specimens found with fresh (with a ragged appearance very different from a healed termini) incomplete self-amputations of the posterior part of the body, notably not consistent with shark bites; the lost part is never regenerated. Oftentimes sighted vertically suspended head-up in clear oceanic or inshore waters with the rays of the two dorsal fin crests usually extended vertically upward while the pelvic fin rays may be horizontally spread outward and away from the body (Ref. 92949). This is hypothesized to be a feeding stance that visually allows the fish to spot the silhouette of its potential prey against the skylight (Ref. 49905). Feed on euphausiid crustaceans, small fishes and squid (Ref. 6738). Toothless protrusile jaws work to suction krill-laden water into its oro-branchial cavity and retained in the gullet by the long, spiny and bristly gill rakers (Ref. 92949). Occassionally associate in pairs (gender undocumented) but no record of group larger than three or of schooling behavior (Ref. 92949). Spawning occurs between July and December and larvae are encountered near the surface (Ref. 9337). Spawns in the North Pacific Ocean, in an area west of the Marianas Islands; also possibly in South Africa near Durban (Ref. 92949). In Guinness Book of Records as longest bony fish (Ref. 6472). Also caught with encircling nets and marketed fresh (Ref. 9337). Reputed to be unpalatable because the flesh is tasteless or otherwise unappetizing (Ref. 92949). Underwater footage shows them slowly swimming vertically, head up, with a stiff body, only undulating the dorsal fin, and with photophores on their appendages. The mouth can be protruded for capturing prey (RF, pers. comm. 2013). A rare species mainly offshore, sometimes drifting to coastal regions (Ref. 41299). Length based on occurrence record from Taiwan.