The Broadnose Sevengill Shark is the only extant member of its genus. Whereas most other sharks have 5 gill slits, sevengill sharks are recognisable because of its 7 gill slits.
Like many other fish, the shark uses counter shading as a of camouflage. Its dorsal surface is silvery grey in colour, which allows it to blend with the dark waters beneath it when viewed from above. Conversely, its ventral surface is light in colour, matching the sunlit surface when viewed from below.
An opportunistic predator, the broadnose sevengill preys on a great variety of animals. It has been found to feed on sharks, rays, chimaeras, cetaceans, pinnipeds, bony fishes, and carrion. These sharks occasionally hunt in packs to take down larger prey, using tactics such as stealth to succeed.
New Hammerhead Shark Species Found Off South Carolina
by Douglas Main
When new species are found near populated areas, they are often small and inconspicuous, not, for example, a hammerhead shark.
But that’s exactly what a team of researchers discovered along the coast of South Carolina. The new species looks virtually identical to the scalloped hammerhead, but is genetically distinct, and contains about 10 fewer vertebrae, or segments of backbone, new research shows.
The new species, named the Carolina hammerhead (Sphyrna gilbert), gives birth to shark “pups” in estuaries near the shore off the Carolinas, according to a study published in August in the journal Zootaxa…
Spiky-Headed Sharks Survived Mass Extinction, Surprising Scientists
An exotic, ancient shark thrived into the age of dinosaurs, study says.
by Dan Vergano
A family of small sharks—some of which had spiky heads—cruised the ancient seas for far longer than scientists had suspected, surviving to about 120 million years ago. Their surprising survival suggests that deep oceans sheltered predators during past mass extinctions.
The giant prehistoric shark Megalodon is one of the few animals to be identified by its species, rather than its genus, name: technically, this predator is known as Carcharodon megalodon, which places it in the same family as the modern Great White Shark. However, not everyone is convinced that this fearsome shark was a direct ancestor of the Great White, hence its popular name Megalodon.
Until a better candidate comes along—which doesn’t seem likely—Megalodon stands as the biggest shark in earth’s history, a true apex predator that counted everything in the ocean as part of its ongoing dinner buffet, including whales, squids, fish and dolphins (there’s some speculation that Megalodon may even have preyed on Leviathan, a giant, prehistoric sperm whale announced to the world in 2010…
Off of the Northeast US Canyons the Okeanos Explorer found a Greenland Shark! These sharks can be between 8-16ft long and weight 880lbs. This shark is normally found in Northern Atlantic waters, but has recently been found as far south as the Gulf of Mexico. Scientists have attributed this wide range of habitat to the fact that deep sea environments, even in warmer environments, resemble the natural habitat of the Greenland Shark.
10 More Cool Sharks You Probably Don’t Hear Much About During Shark Week
So I know that Shark Week is over now, but I couldn’t just stop at 10, so here are 10 more!
Angel Shark (Squatina) There are 23 different species of angel shark and all live in shallow, warm seas, though some migrate to warmer waters during the summer. Most types grow to a length of 5 ft (1.5 m). They hunt at night in their own territories. Unlike rays, they have sharp teeth for feeding on shelled prey and small fish. They disguise themselves from prey by covering their bodies in sand and often having sandy-colored skin. An angel shark is hard to see as it lies on the seabed. Its body is so flat that it appears no more than a low mound in the sand. Unlike a ray, it uses its tail rather than its large fins to swim. Read more about this shark…(read more)
The Port Jackson Shark, Heterodontus portusjacksoni
… is a common inhabitant of the continental shelf of Southern and Western Australia. It feeds on benthic invertebrates, primarily echinoderms. The teeth of the Port Jackson Shark are unusual. They are not serrated, and the front teeth have a very different shape from those found at the back of the jaws. The anterior teeth are small and pointed, whereas the posterior teeth are broad and flat. The teeth function to hold and break, then crush and grind the shells of molluscs and echinoderms. This shark is considered harmless to people, but can deliver a painful nip when provoked.
Phylogenetic studies based on morphology have generally placed the goblin shark as the most basal member of the order Lamniformes, known as mackerel sharks. Studies using genetic data have also supported a basal position for this species.
The family Mitsukurinidae, represented by Mitsukurina, Scapanorhynchus, and Anomotodon, dates back to the Aptian age of the Cretaceous period. Mitsukurina itself first appears in the fossil record during the Middle Eocene extinct species include M. lineata and M. maslinensis.Striatolamia macrota, which lived in warm shallow waters during the Paleogene, may also be a Mitsukurina species. As the last member of an ancient lineage, and one that retains several “primitive” traits, the goblin shark has been described as a “living fossil”…
Mission: To allow trained SCUBA divers to log encounters with Sevengill Sharks
…1. Be SCUBA certified 2. NEVER endanger yourself around sharks to have an encounter. NEVER touch a shark. If it exhibits what appears to be aggressive behavior, get out of the water immediately. 3. If you think you’ve seen or encountered a Sevengill shark, go to [www.sharksonline.net] and log your encounter there first. 4. Then, come here and log your encounter here. The Shark Observation Network is the primary database. For more information on this project, see: http://sevengillsharksightings.org/
The Japanese roughshark is a rare species of shark in the family Oxynotidae, known only from a handful of specimens recovered from Suruga Bay and the Enshunada Sea off Japan. It is a benthic species that occurs at a depth of 150–350 m. This shark is caught (and discarded) as by-catch by bottom trawlers throughout its entire limited range, and may be threatened given the declines in other bottom deep sea species in Suruga Bay.
This species grows to 64.5 cm long. It is similar to other rough sharks in having a stout, high trunk, a dorsally depressed head, and two sail-like dorsal fins with deeply embedded spines. The snout is short, with large nostrils whose lateral and medial apertures are separated by a thick nasal flap. The eyes and spiracles are oval in shape. The five pairs of gill slits are very small and vertical. The mouth is small, with thick, fleshy lips; the teeth in the upper jaw are narrow, erect, and smooth-edged, while those in the lower jaw are broad, blade-like, and smooth-edged. Only one row of teeth in the lower jaw are functional…
You Can Help: Saving Reefs By Using Citizen Scientists
Ever wanted to see a coral reef up close? What until now has been a privilege reserved to a small minority is about to become something millions of us can (virtually) do.
Scientists have hit on a way to harness 360-degree panoramas from Google’s underwater street-view format in order to let anyone with access to a computer see reefs in real time.
The project – which will allow ecologists to harness this distributed power to study how coral reefs are responding to climate change – was presented at INTECOL, the world’s largest international ecology meeting, in London this week.
Professor Ove Hoegh-Guldberg of the University of Queensland, Australia, leads the research associated with the Catlin Seaview Survey. It aims to create a baseline record of the world’s coral reefs, in high-resolution 360-degree panoramic vision…