Sevengill Shark

Subclass Elasmobranchi—Sharks and Rays

 Order Hexanchiformes —  Cow Sharks—Family Hexanchidae

A sevengill taken from the Oyster Point Pier by Matt Shockley in 2003

Species: Notorynchus cepedianus (Perón, 1807); from the Greek roots noto (back) and r(h)ynchos (snout); and the Latin cepidianus (spotted).

Alternate Names: Broadnose sevengill shark, cow shark, spotted cow shark, mud shark, bluntnose shark, broad-snout, sevengill, k’wet’thenéchte (Salish, British Columbia), and my personal favorite (from Australia) Tasmanian tiger shark. This is another shark with an almost worldwide distribution and as a result it has many foreign names including cação-bruxa (Portuguese), cañabota gata (Spanish), gatita (Spanish), gevlekte zevenkieuwshaai (Dutch), brednæset syvgællet haj (Danish), kammzähner (German), koeihaai (Afrikaans), platneus-sewekiefhaai (Afrikaans), minami-ebisuzame (Japanese), ebisuzame (Japanese), platnez (French), requin malais (French), siebenkiemiger Pazifischer kammzähner (German), siedmioszpar plamisty (Polish), tiburón de 7 gallas (Spanish), tiburón pinto (Spanish), tollo fume (Spanish), and tuatini (Maori).

A sevengill from the Dumbarton Pier in 2004

Identification: The only California shark with 7 gill slits. The body is somewhat heavy and flabby, tapered with a broad head, blunt snout, and small eyes. They have a single dorsal fin far back on the body; upper lobe of tail is very long. Five rows of small, sharp, pointed teeth in the upper jaw—except for one middle tooth (effective for holding prey); lower teeth saw-like (effective for tearing and cutting prey). Color seems to vary depending upon location and they may be able to slightly alter their color. Fish from San Francisco Bay are typically olive brown to a muddy gray color, those from Humboldt Bay are usually a pale silvery gray to reddish brown: all have black spots on body and fins. An unusual albino seven-gill was caught in the San Mateo Shark Derby back in 1952 and later displayed at the Steinhart Aquarium.

Size: Length to over 9 feet and nearly 300 pounds in size. Most sevengills caught from piers are young fish 2-4 feet in length and under 50 pounds in weight. However, most years seem to see at least a few large 6-foot plus fish taken.

A good-sized sevengill taken from the Goleta Pier in 2009

The largest sevengill reported to PFIC was a sevengill taken from the Cayucos Pier in December of 1998. Pictures show a large 7 ½-foot-long fish but the reported weight of 180-pounds seems fat too high. Two large 7-gills were reported from the Ocean Beach Pier. In May of 2006, a nearly 8-foot-long, 112-pound 7-gill shark was landed, while May of 2008 saw the capture of a 7-gill estimated to be 10-10 ½ feet long. The only problem is that 7-gills are only supposed to reach about 9 feet in length. (Perhaps it was a 6-gill (they’ve been reported to 15 feet in length?) In October 2009 the Goleta Pier saw the capture of both a six-foot and eight-foot 7-gill. Just a month later saw another 7-gill, this one a seven-foot, nine-inch fish. The California record fish weighed 276 lb 0 oz and was taken in Humboldt Bay in 1996.

The large sevengill taken from the Cayucos Pier by Wayne in 1998. Although the weight is disputed by many, it was still a LARGE sevengill for a pier.

Range: Found in temperate waters of the Pacific, Indian and South Atlantic Oceans (and very common off South Africa and Namibia). Found in North America from the Gulf of California to northern British Columbia off Butedale and Bonilla Island. Common in central California.

Habitat: A bottom oriented shark common to inshore areas (especially rocky areas near kelp) and in bays, especially San Francisco Bay, Tomales Bay and Humboldt Bay. Most common from the spring to the fall; may migrate to deeper water during the winter. In San Francisco Bay, springtime sees mama sevengill dropping her pups (up to 82 young ‘uns) and that’s when small, immature fish make a regular appearance at several piers.

Most sevengills caught from piers are smaller fish such as this one taken from the Berkeley Pier in 2004

Piers: Mainly caught at piers that sit close to fairly deep water, or deep-water channels in a bay. Best bets: Ocean Beach Pier, Redondo Beach Pier, Goleta Pier, Morro Bay T-Piers, Cayucos Pier, Oyster Point Pier, Dumbarton Pier, Berkeley Pier, Elephant Rock Pier, Angel Island Pier, and the Del Norte Street Pier (Eureka).

Shoreline: Sometimes caught from shoreline areas in San Francisco Bay, most commonly early spring or late fall when the fish appear to move into shallower areas to spawn.

Showing that large sevengills are occasionally seen on piers and in shoreline areas is this large sevengill that was caught from the shoreline at Pismo Beach in 2010

Boats: A common goal for anglers fishing from boats in San Francisco and Humboldt Bay.

Bait and Tackle: An opportunistic predator that feeds on many other fish including salmon, sturgeon, smaller fish, rays and fellow shark. It’s reported that 7-gills sometimes hunt in packs and use teamwork to capture larger food such as seals and dolphins. However, the use of seal meat and dolphin meat for bait by humans tends not to be PC (it’s also illegal). Instead, typical baits include whole fish such as mackerel and sardines, whole squid, small sharks, and salmon bellies.  Typically anglers seeking out sevengills use heavier tackle—50+ pound line and steel leaders baited with a whole fish (and I heard of one angler using a live small brown smoothhound shark as bait). For the most part, anglers fishing for bat rays or other species of sharks catch these fish. (One angler suggested that at the Elephant Rock Pier, due to the rocky location, an angler might want to use a wire 90# plastic coated hi/lo with large circle hooks. Fish an incoming tide with at least a six-ounce weight and some landing apparatus.

A sevengill taken at the Dumbarton Pier in 2004

Food Value: Considered one of the best eating sharks.

Comments:  One of the most primitive of sharks as well as one of the largest and more dangerous sharks handled by California pier fishermen. Watch out for the teeth! David A. Ebert, in Sharks Rays, and Chimaeras of California, writes that “Other than the Great White Shark they appear to be the dominant elasmobranch in the nearshore marine environment.”

Another sevengill from the Dumbarton Bridge Pier, this one taken in 2006.

In addition, “Sevengills have been implicated in about a dozen attacks on dogs in and around San Francisco Bay. A bather in at least one attack was playing with his dog in shallow water when a 1.5- to 1.8-m-long ‘spotted’ shark attacked. Although the shark was unidentified, the attack occurred inside San Francisco Bay in an area in which sevengills are fairly abundant.” It’s also reported that 7-gills have bitten aquarium divers.

Shark teeth at the Berkeley Pier in 2008

Sevengill caught at the Robert Wooley Pier (Burlingame) in 2007

A sevengill taken by Rock Hopper at the Berkeley Pier in 2004

The capture of a large sevengill by Matty and Dom in 2012; picture by capt.raysharking

 

 

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