Broadnose Sevengill Shark: Understanding Its Biology and Threats

The broadnose sevengill shark is a fascinating creature that has been on our planet for over 300 million years, with fossil records dating back to the Early Cretaceous period.

Reaching lengths of up to 20 feet and weighing over 2,000 pounds, these sharks are one of the largest predatory fish on the planet.

Their unique appearance, with a broad, flat snout and seven distinctive gill slits, makes them easily recognizable in the ocean.

They are a deep-water species, typically found between 100 to 2,000 feet below the surface, where the pressure is extreme and the light is scarce.

The broadnose sevengill shark is a large species with a thick body, broad head, and blunt snout. It can grow up to 300 cm (9.8 ft) in length and weigh up to 107 kg (236 lbs).

Its dorsal surface is silver-gray to brown and the ventral side is very pale. The body and fins are covered in small black and white spots.

This shark has a single dorsal fin that is set far back along the spine, behind the pelvic fins towards the tail fin. The upper portion of the tail fin is much longer than the lower portion and is slightly notched near the tip.

The broadnose sevengill shark is a large species with a thick body and a broad head. Its blunt snout is a distinctive feature that sets it apart from other shark species.

This shark's dorsal surface is silver-gray to brown, while its ventral side is very pale. The body and fins are covered in small black and white spots.

It has a single dorsal fin that's set far back along the spine, behind the pelvic fins towards the tail fin. The upper portion of the tail fin is much longer than the lower portion and is slightly notched near the tip.

The broadnose sevengill shark can grow up to 300 cm (9.8 ft) in length, and 107 kg (236 lbs) in weight.

The broadnose sevengill shark is a remarkable creature, and its size is one of its most impressive features. At birth, they measure 15 to 17 inches.

As they mature, males reach almost 5 feet in length, while females reach a whopping 7 feet. The largest recorded broadnose sevengill shark was an impressive 9.8 feet long.

These sharks can live up to 49 years, which is a testament to their resilience and adaptability.

The Broadnose Sevengill Shark, also known as the cowshark, is a remarkable creature.

Its name, Broadnose Sevengill Shark, is actually a scientific classification, Notorynchus cepedianus.

This shark can be found in False Bay, Western Cape, South Africa.

The broadnose sevengill shark is a fascinating creature that can be found in various parts of the world.

They inhabit the western Pacific Ocean off China, Japan, Australia, New Zealand, the eastern Pacific Ocean off Canada, United States, and Chile, and the southern Atlantic Ocean off Argentina and South Africa.

Large individuals tend to live in deeper offshore environments, with some as deep as 446 feet.

Most individuals, however, live in the deep channels of bays or in the shallower waters of continental shelves and estuaries.

This shark species likes to swim slowly near the bottom, but it also makes the occasional surface trip to hunt for food.

They can be found in shallow waters, continental shelves, bays, and estuaries, including San Francisco Bay, Tomales Bay, and Humboldt Bay.

Seasonal movements into and out of estuaries, such as Willapa Bay and Grays Harbor, occur for mating and pupping.

In South Africa, individuals that live closer to the coast tend to prefer more open areas with a sandy sea floor and sparse clumps of kelp.

Additional reading: Extinct Sharks Found Alive

The broadnose sevengill shark is listed as Vulnerable throughout its range, likely suffering from ongoing pressure from various fisheries and frequent bycatch.

This species is threatened by water pollution, and its liver oil and hide are highly valued in countries like China.

In Argentina, broadnose sevengill sharks are caught by rod and reel, and fishing competitions have been occurring since the 1960s.

The broadnose sevengill shark is also hunted for its meat and fins, which are in high demand in countries such as the US, Brazil, Spain, Germany, Netherlands, and Israel.

Its meat is packaged for frozen food, and it's a source of vitamin A.

However, the broadnose sevengill shark is not easy to land despite being readily hooked.

Conservation measures are limited, but it has been recorded from one marine reserve in South Africa.

In some areas, like La Jolla Cove in San Diego, California, the broadnose sevengill shark population appears to be increasing.

Recreational fishing of broadnose sevengill sharks is closed in all state waters in Washington state, and in Victoria, Australia, there's a one bag limit and the shark must be whole or in carcass form.

The broadnose sevengill shark is a formidable predator with a voracious appetite. It feeds on a wide variety of prey, including other sharks, seals, rays, and even dolphin and porpoise meat.

This shark's diet is incredibly diverse, and it will eat just about anything it can catch. Shark egg cases are also on the menu.

The broadnose sevengill shark is a scavenger at heart, and it will feed on mammalian carrion, including rats. This opportunistic feeding behavior allows it to thrive in its environment.

Its diet also includes hagfish, bony fish, and sea snails, making it a top predator in its ecosystem.

The broadnose sevengill shark is a species that's heavily impacted by human activity.

Human fishing practices have led to their decline, with the species being caught accidentally in deep-sea fishing gear.

Their habitat is also threatened by coastal development and pollution, which can alter the ocean's chemistry and disrupt their food supply.

The broadnose sevengill shark is a deep-sea dweller, often found in areas with low oxygen levels, making them more vulnerable to changes in the ocean's chemistry.

Interactions with humans have been a concern for the ISAF, who consider the sevengill shark potentially dangerous due to its aggressive behavior when provoked. This behavior has been observed in both public aquariums and the wild.

In 2013, a sevengill shark bit a diver's regulator and then her head in Fiordland, New Zealand. Human remains were also supposedly found in one specimen's stomach.

Seven attacks on humans by the broadnose sevengill have been recorded since the 16th century, with no known fatalities. However, a 13-year-old girl was bitten while surfing at Oreti Beach in New Zealand in 2020.

Fishing for the broadnose sevengill shark is a challenge because there are very few of its species and it matures slowly.

The best way to catch this fish is on a 40- to 50-pound tackle baited with whole fish such as sardines or mackerel.

Surf rigs will also work well with fishing for the broadnose sevengill shark. Make sure to use rigs made with wire or cable as the teeth of this shark species can cut through the rig.

The best season to fish for this shark species is spring when they gather up for breeding. They stay on for several days, making it a good time to catch them.