Thresher (Pelagic)

Max length : 347 cm TL male/unsexed; 383.0 cm TL (female); common length : 276 cm TL male/unsexed; max. reported age: 29 years

Family	Alopiidae
Description	Thresher sharks
Environment	Marine
Etymology	Greek, alopex = fox
Genus	1
No. of Species	3
Order	Lamniformes
Class	Elasmobranchii
Reproductive Guild	Bearers
Distribution	Marine; all oceans. Upper lobe of caudal fin greatly elongate, caudal fin almost one-half of total length; third to fifth gill openings over origin of pectoral fin. Ovoviviparous, embryos feeding on yolk sac and other ova produced by the mother

Primarily an oceanic species but sometimes close inshore neritic to oceanic, 0-152 m. Epipelagic. Mesopelagic in the tropics; may enter atoll lagoons. Stuns its prey with its tail, presumably feeding on small fishes and cephalopods. Ovoviviparous, embryos feeding on yolk sac and other ova produced by the mother. Sometimes caught by ski-boat anglers. A very common catch in the tuna and shark longline, and tuna drift net fisheries. Adult females may reach at least 330 cm TL

Dorsal spines (total): 0; Dorsal soft rays (total): 0; Anal spines: 0; Anal soft rays: 0. A small thresher with moderately large eyes, a broadly convex forehead, a very narrow caudal tip, and straight, broad-tipped pectoral fins. 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. Dark blue on back and sides, underside white; no white patch over pectoral fin bases

Exhibit ovoviparity (aplacental viviparity), with embryos feeding on other ova produced by the mother (oophagy) after the yolk sac is absorbed. Usually with at least two young. Size at birth about 100 cm; 130-160 cm TL. Distinct pairing with embrace

Summary of Distribution: Circumglobal. Indo-Pacific: Red Sea, Arabian Sea, Maldives, 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.
Note: Distribution range colors indicate degree of suitability of habitat which can be interpreted as probabilities of occurrence (fishbase.org)