Common Thresher Shark

Thresher taken at the Goleta Pier by Big Red

Thresher Sharks: Family Alopiidae

Species: Alopias vulpinus (Bonnaterre, 1788); from the Greek word alopos and Latin word vulpes, (both meaning fox).

Alternate Names: Thresher, blue thresher, longtail shark, swiveltail, fox shark, sea fox, fish shark, sea ope, pesca pavone. A worldwide range with a worldwide list of foreign names—pez zorro (Spanish), cação-pena (Portuguese), faux (French), fuchshai (German), aleposkylos (Greek), big-eye thresher (English), budenb (Maltese), cacao-raposa (Portuguese), chichi espada (Spanish), coleto (Spanish), coludo (Spanish), coludo pinto (Spanish), drescherhai (German), grayfish (English), grillo (Spanish), guadaña (Spanish), guilla (Catalan), jarjur (Arabic), kalb (Arabic), karage (Swahili), kettuhai (Finnish), Kosogon (Polish), K’wet’thenéchte (Salish), Langschweif (German), Loup de mer (French), mango-ripi (Maori), ma’o aero (Tahitian), mao-naga (Japanese), papa kinengo (Swahili), pas lisica (Serbian), pating (Tagalog), pèis rato (French), peixe-rato (Portuguese), peje sable (Spanish), peje zorra (Spanish), pejerrabo (Spanish), pesce volpe (Italian), peshkdhelpën (Albanian), pez espada (Spanish), pez palo (Spanish), pichirata (Spanish), pixxivolpi (Maltese), poisson-épée (French), psina lisica (Serbian), qatwa al bahar (Arabic), rabilongo (Portuguese), rabo de zorra (Spanish), rævehaj (Danish), raposa (Spanish), raposa marina (Spanish), raposo (Portuguese), rävhaj (Swedish), rechin-vulpe (Rumanian), renard (French), renard de mers (Creole), renard marin (French), requin renard (French), revaháur (Faroese), revehai (Norwegian), romano (Portuguese), romão (Portuguese), sapan (Turkish), sapan baligi (Turkish), seefuchs (German), singe de mer (French), skylópsaro (Greek), squalo volpe (Italian), tærsker (Danish), te bakoa (Kiribati), te kimoa (Kiribati), thon blanc (French), tiburón zorro (Spanish), tubarão raposo (Portuguese), volpe de mar (Italian), voshaai (Dutch), watwa albahar (Arabic), whip-tailed shark (English), zoro cauda longa (Portuguese), zorro (Spanish), and zorro blanco (Spanish).

Identification: Easily identified by the long tail (caudal fin) that is as long as the rest of the body. Their coloring is brown to bluish gray to black to purplish on the back shading to white below. Their overall shape is spindle-shaped with two dorsal fins, a tiny anal fin, and curved pectoral fins. They have a short snout with a mouth full of small but sharp teeth. The only other similar sharks in California water are the deep-water, big-eye thresher and the pelagic thresher (both generally seen only during warm water years).

A baby thresher taken at the Pacifica Pier

Size: To at least 18.8 feet and possibly 20.9 feet. Most caught from piers are youngsters 6-7 feet in length. The California record fish was a 575 lb 0 oz fish caught off Carlsbad Canyon in 2007.

Range: Circumglobal in warm waters. Found in the eastern Pacific south to Chile and north to Goose Bay, British Columbia, and southeastern Alaska. Common locally from Punta Eugenia, Baja California, to southern California. The majority of threshers caught in California are taken south of Point Conception.

Habitat: Most common in deeper offshore water but young threshers venture into shallower water. Found from the surface down to about 2,300 feet deep. A species increasingly targeted by southern and central California pier rats.

Piers: Most common on oceanfront piers south of Point Conception although some are taken every year from Central Coast piers. Best bets: Ocean Beach Pier, Oceanside Pier, San Clemente Pier, Balboa Pier, Newport Pier, Huntington Beach Pier, Redondo Beach Pier, Hermosa Beach Pier, Venice Pier, Santa Monica Pier, Malibu Pier, Ventura Pier, Gaviota Pier, and Pismo Beach Pier. Gaviota may be the best pier in the state for threshers; perhaps the nearby waters are a “pupping” area?

Shoreline:Rarely caught from shore unless near deep-water areas.

Boats: A major species for both boaters and kayakers in southern and central California. Live bait is preferred but they aren’t easy to land from a kayak.

A nice thresher taken at the Caucus Pier

Bait and Tackle: Bony fish make up 97% of the thresher’s diet. Mostly these are small, schooling species such as mackerel, jack mackerel and sardines. As a result, the recommended bait is a live whole fish with mackerel and sardines leading the list. A whole squid also makes excellent bait. Anglers specifically fishing for them land the great majority of threshers. Tackle should be heavy and include a net or treble-hook gaff to bring the fish onto the pier. Line should be at least 40-pound test, a wire leader is preferred and hooks can be 4/0 or larger.

Food Value: An excellent, mild-flavored fish with firm texture, large flakes, and white coloring after cooking. It has moderate fat content. Threshers can be prepared many ways but one of the best is to simply cut the meat into steaks and broil them on a grill. The meat does need to be cleaned properly and kept cool before cooking.

Comments: The high demand for thresher steaks, accompanying high prices, over-fishing, and low number of pups birthed each year by females (two to four), have led to a dramatic drop in the thresher population in the last twenty years. Many people feel there should be either a ban or severe limits imposed on the take of threshers.

A thresher taken from the jetty at Half Moon Bay