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WHAT IS ELASMODIVER?

Not just a huge collection of Shark Pictures: Elasmodiver.com contains images of sharks, skates, rays, and a few chimaera's from around the world. Elasmodiver began as a simple web based shark field guide to help divers find the best places to encounter the different species of sharks and rays that live in shallow water but it has slowly evolved into a much larger project containing information on all aspects of shark diving and shark photography.

There are now more than 10,000 shark pictures  and sections on shark evolution, biology, and conservation. There is a large library of reviewed shark books, a constantly updated shark taxonomy page, a monster list of shark links, and deeper in the site there are numerous articles and stories about shark encounters. Elasmodiver is now so difficult to check for updates, that new information and pictures are listed on an Elasmodiver Updates Page that can be accessed here:

WHAT'S NEW?

Shark picture - green sawfish

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BROADNOSE SEVENGILL SHARK

Broadnose Sevengill Shark

Broadnose Sevengill Shark

View all available Broadnose Sevengill Shark Pictures in the Shark Pictures Database

Common Names: Broadnose Sevengill Shark, Spotted Sevengill Shark, Spotted Cow Shark.

Latin Name: Notorynchus cepedianus.

Family: Hexanchidae

Identification: Bluntly rounded snout. Seven gill slits, posterior slits very short. Single dorsal fin set well back on body. Upper body sprinkled with small black spots and usually some white spots. Large size.

Size: At birth 34-45cm. Males mature at 130-170cm. Females mature at 200cm. Maximum recorded size 290cm. May possibly grow to 400cm.

Habitat:  Coastal sandy bays and rocky shorelines up to the surf line. Larger individuals inhabit deeper channels. Recorded at 136m but usually found in 1-50m.

Abundance and distribution: Temperate coastal waters around the world. Southern Australia, New Zealand, Japan,  Southern Africa, east and west coasts of south South America, and west coast of North America to Alaska.

Behavior and Diet: Cruises steadily along bays in search of food moving in and out with the tides. Prefers low visibility - night, turbid water, overcast conditions. Known to aggregate possibly for mating. Footage from the documentary Shark Quest shows a group of Broadnose Sevengill Sharks feeding together on a stingray carcass. Preys on sharks and rays, bony fishes and marine mammals.

Reproduction: Ovoviviparous (aplacental viviparous). Litter size 67-104. but may be higher. Gestation probably around one year followed by one year of recovery.

Observations: Broadnose Sevengill Sharks have been observed spy hopping - holding their heads above water and seeming to look around. This behavior is rare among sharks but has been regularly observed in Great White Sharks. It may be an adaptation to aid in the capture of marine mammals.

Conservation Status: The IUCN lists this shark as 'Data Deficient'. However the IUCN notes that the broadnose sevengill's flesh is sought after in some markets. It is also taken in some areas for its hide and liver oil. Intensive commercial and sports fisheries in San Francisco Bay targeting it for its fine meat caused a marked local decline in numbers during the early 1980s. It is utilised in China for its skin and liver. Pollution may be a possible threat to inshore bays which are sevengill nurseries.
Although wide ranging in temperate waters and moderately common where not heavily exploited (e.g., southern Africa), this large shark has a limited inshore bathymetric range in heavily fished temperate waters and is often concentrated in shallow bays. This exposes it to intensive inshore bycatch and sometimes targeted commercial, sports and semi-commercial fisheries over most of its range, particularly off China, California, Argentina, Namibia and South Africa (Compagno in prep. a). Catch statistics are not reported, except for the west coast of the USA, which show a peak in landings of 1.55 t in 1981 with a sharp decline to less than 0.1 t in 1986 (Compagno in prep. a).

Similar species: The Bluntnose Sixgill Shark (Hexanchus griseus) has a very similar body shape but lacks the seventh gill slit and has less or no spots. The Sharpnose Sevengill Shark (Heptranchias perlo) has much larger eyes, a more pointed snout, and flattened, elongated pelvic fins.

Reaction to divers: The Broadnose Sevengill sharks tend to ignore divers but they will turn and swim away when intercepted. Sevengills can become aggressive in baited situations e.g. towards spear-fishermen. In captivity it has bitten aquarium divers.

Diving logistics: Although this shark has a broad distribution it is not commonly encountered by divers in most areas. However, Miller's Point off of Simon's Town near Cape Town, South Africa offers extremely reliable sightings.

Sevengill shark sightings along the coast of Southern California are also increasing. La Jolla Cove is a particularly good site where multiple sharks can sometimes be seen on a dive. Divers sometimes carry bait in this area to encourage encounters.

 

Other colloquial and foreign names for Notorynchus cepedianus:

哈那鯊 - China Main Mandarin Chinese

哈那鲨 - China Main Chinese

油夷鮫 - Taiwan Mandarin Chinese

扁头哈那鲨 - China Main Chinese

扁頭哈那鯊 - China Main Mandarin Chinese

斑点哈那鲨 - China Main Chinese

斑點哈那鯊 - China Main Mandarin Chinese

扁头哈那鲨的异名 - China Main Chinese

扁頭哈那鯊的異名 - China Main Mandarin Chinese

Brednæset syvgællet haj - Denmark Danish

Broad snouted sevengill - New Zealand English

Broad-snout - Australia English

Cação-bruxa - Brazil Portuguese

Cañabota gata - Spain Spanish

Cowshark - Australia English

Ebisuzame - Japan Japanese

Gatita - Ecuador Spanish

Gevlekte zevenkieuwshaai - Netherlands Dutch

K'wet'thenéchte - Can Br Colum Salish

Kammzähner - Germany German

Koeihaai - Namibia Afrikaans

Minami-ebisuzame - Japan Japanese

Pacific seven-gill shark - UK English

Platneus-sewekiefhaai - South Africa Afrikaans

Platnez - France French

Requin malais - Mauritius French

Seven-gill cowshark - Namibia English

Seven-gilled shark - Australia English

Siebenkiemiger Pazifischer Kammzähner - Germany German

Siedmioszpar plamisty - Poland Polish

Širokonosý sedmižaberní žralok - Czech Rep Czech

Tasmanian tiger shark - Australia English

Tiburón de 7 gallas - Spain Spanish

Tiburón pinto - Mexico Spanish

Tollo fume - Spain Spanish

Tuatini - New Zealand Maori

Žralok plochohlavý - Czech Rep Czech

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