Alopias pelagicus Nakamura, 1935
Pelagic thresher
Pelagic thresher,  Pating
Alopias pelagicus
photo by Romanov, E.V.

Family:  Alopiidae (Thresher sharks)
Max. size:  428 cm TL (male/unsexed); 383 cm TL (female); max. reported age: 29 years
Environment:  pelagic-oceanic; marine; depth range 0 - 300 m, oceanodromous
Distribution:  Circumglobal. Indo-Pacific: Red Sea, Arabian Sea, Maldives (Ref. 30829), Somalia, South Africa, Western Australia, China, Taiwan, Japan, New Caledonia, Hawaiian Islands and Tahiti. Eastern Pacific: Gulf of California and the Galapagos. Reliable records lacking partly due to its confusion with Alopias vulpinus.
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 0-0; Anal spines: 0-0; Anal soft rays: 0-0. A small thresher with moderately large eyes, a broadly convex forehead, a very narrow caudal tip, and straight, broad-tipped pectoral fins (Ref. 5578). Upper lobe of caudal fin very long and strap-like, almost equal to length of rest of shark; lower lobe short but strong; terminal lobe very small (Ref. 13570). Dark blue on back and sides, underside white; no white patch over pectoral fin bases (Ref. 5578).
Biology:  Primarily an oceanic species but sometimes close inshore (Ref. 247, 5578, 58302); neritic to oceanic, 0-152 m (Ref. 11230). Epipelagic (Ref. 58302). Mesopelagic in the tropics; may enter atoll lagoons (Ref. 37816). Stuns its prey with its tail, presumably feeding on small fishes and cephalopods (Ref. 6871). Ovoviviparous, embryos feeding on yolk sac and other ova produced by the mother (Ref. 43278, 50449). Sometimes caught by ski-boat anglers (Ref. 5578). Utilized for human consumption, liver oil for vitamin extraction, hides for leather, and fins for shark-fin soup (Ref. 13570). A very common catch in the tuna and shark longline, and tuna drift net fisheries (Ref.58048). Maximum and common size of males estimated from discussion in Ref. 247. Adult females may reach at least 330 cm TL (Ref. 47613).
IUCN Red List Status: Endangered (EN); Date assessed: 06 November 2018 (A2bd) Ref. (126983)
Threat to humans:  harmless
Country info:  First record of the species; specimens collected from Fish Ports of Cebu and Cadiz cities (Ref. 47736, 47737). Also Ref. 110893, 121724.

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