Endangered
Pelagic thresher
Alopias pelagicus
Pelagic thresher is a shark or ray in the family Alopiidae (order Lamniformes) — Alopias pelagicus, recorded as Endangered.
Appearance
This species has a fusiform body (wide in the middle and tapered at the ends) and a very slender upper caudal fin lobe nearly as long as the rest of the shark. The second dorsal and anal fins are tiny. The head is narrow with a short, conical snout and a distinctive "pinched" profile when viewed from below.
The pelagic thresher is the smallest of the thresher sharks, typically 3 m (10 ft) in length and 69.5 kg (153.2 lb) in weight, and usually not exceeding 3.3 m (11 ft) and 88.4 kg (195 lb).
Males and females attain known maximum lengths of 3.5 m (11 ft) and 3.8 m (12 ft), respectively. The young are born unusually large, up to 43% the length of the mother.
Range and habitat
It ranges extensively in the Indo-Pacific, with scattered records from South Africa, the Red Sea, and the Arabian Sea (off Somalia, between Oman and India, and off Pakistan), to China, southeastern Japan, northwestern Australia, New Caledonia, and Tahiti, to the Hawaiian Islands, California, and the Galapagos Islands. The pelagic thresher primarily inhabits the open ocean, occurring from the surface to a depth of at least 150 m (490 ft). Even so, it occasionally comes close to shore in regions with a narrow continental shelf, and has been observed near coral reef dropoffs or seamounts in the Red Sea and the Gulf of California, and off Indonesia and Micronesia.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet
Cleaner fish feed most frequently in the pelvic and caudal fin (tail) regions of the visiting sharks, potentially due to the parasitic digeneans present in the cloaca, and the damage to the skin of the caudal fin caused by their tail-slap hunting strategy. The diet of the pelagic thresher consists mainly of small midwater fishes, that are stunned with whip-like strikes of its tail.
In crisis
The International Union for Conservation of Nature assessed this species as endangered in 2019.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Pelagic thresher is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Pelagic thresher, Wikidata item Q1274522. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
