BROADNOSE SEVENGILL COW SHARK

Notorynchus cepedianus

Where you can see them:
Simon’s Town

BROADNOSE SEVENGILL COW SHARK SOUTH AFRICA

Join Dive The Big 5 on a unique dive in the magical kelp forests of the Cape Peninsula in search of Broadnose Sevengill Sharks (Notorynchus cepedianus; Cow sharks).

False Bay is one of the only places in the world that you can consistently dive with over 10 and up to 70 of these ancient looking sharks. Sevengill Sharks are formidable predators of Cape Fur Seals, other species of shark and fish. They can reach lengths of 3m and wight up to 700 pounds. What adds to the unique experience is that because of their natural curiosity and confidence we don’t use any form of chum or bait to interact with them.

Then for a second dive we will introduce you to the best dive buddies you will ever have, the Cape Fur Seal. Dive with up to 40 of these energetic characters at a time. The fur Seals are masters of the underwater world and they will amaze you with their acrobatics.

Question is: who is playing with who on this dive?

There are four species of Cow Sharks. The Bluntnose Six-Gill Cow Shark, the Big-eyed Six-Gill Cow Shark; the Broadnose Seven-Gill Cow Shark; and the Sharp Nose Seven-Gill Cow Shark. The seven gills of the Broadnose Seven-Gill Cow Shark links them to Triassic period sharks making them the most primitive species of shark. All other sharks (with the exception of the Six-Gill Cow Sharks) have five gills. Male Broadnose Seven-Gill Cow Sharks mature at 4-5 years of age, measuring between 130 and 170 cm in length. Females mature at 11 years, at an average length of 200 cm. The life span is estimated to be up to 50 years.

Distribution

Broadnose Seven-Gill Cow Sharks are found at depths of between 1 – 50 meters in the temperate coastal waters of South Africa, southern Australia, New Zealand, Japan, east and west coasts of South America and the west coast of North America, up to Alaska. They prefer low visibility and can co-ordinate their movements according to the tides, enabling them to move in and out of kelp forests that are found in the False Bay area of the Cape Peninsula and in and out of shallow bays which are also commonly found off the Cape Peninsula.

Reproduction

Broadnose Seven-Gill Cow Sharks are ovoviviparous which means they do not lay eggs but give birth to their young. Gestation is approximately 12 months followed by a year of “recovery.” Females usually give birth to large litters, of between 80 to 100 pups measuring between 34 – 45 cm at birth.

Feeding

Broadnose Seven-Gill Cow Sharks are effective predators and scavengers, often hunting in packs. Appearing slow and cumbersome, they are in fact capable of an amazing burst of speed when attacking their prey. Juvenile Broadnose Seven-Gill Cow Sharks eat small sharks, bony fish, and smaller rays, whilst adult Broadnose Seven-Gill Cow Sharks prey on sharks, rays, seals (of which there are thousands in False Bay), dolphins, bony fish, carrion, octopuses, skates, molluscs and crustaceans. Adults only feed sporadically, sometimes once every 5-7 days. New born pups eat about 10 times what the adults eat, and feed for more often.

Behaviour

Broadnose Seven-Gill Cow Sharks, in certain locations, have been observed spy hopping – holding their heads above the water, and seemingly to look around. This behaviour is rare amongst sharks, but has been regularly observes in Great Whites. It is thought to be an adaptation to aid in the capture of marine mammals. Broadnose Seven-Gill Cow Sharks tend to ignore divers and are sometimes quite inquisitive, swimming directly towards divers and turning away at the last minute, or swimming over the divers heads. When visibility is poor, they are a lot more confident and tend to approach far more closely than they otherwise would. They will, however, turn and swim away when intercepted. Their main predators are Great White Sharks and larger Broadnose Seven-Gill Cow Sharks.

• Meeting time depends on the weather but it should be more or less anytime between 9am and 11am.
• On arrival at the dive shop we will dispense with the formalities of signing indemnities, kitting up and the pre-dive planning.
• You will board the boat after all the above is done, the dive site is about a 20minute boat ride from Simon’s town pier.
• The first tank dive will be with the 7gills (as described above)
• Between dives we will have a lunch and snack break, before being briefed for the second tank dive with the Cape Fur Seals.
• The 2 tank dive trip will be around about 3-4hours, depending on the weather and animals.

The likelihood of encountering a Broadnose Seven-Gill Cow Shark when on a diving trip to South Africa?

Dive The Big 5 runs regular Broadnose Seven-Gill Cow Shark/reef/kelp/Cape Fur Seal combination two-tank, in-shore dives, out of Simon’s Town. Broadnose Seven-Gill Cow Sharks are regularly encounted all year round. Refer to Dive The Big 5’s Shark Timetable

Shark Time Table

Please note that the Sharks have not read this timetable so they have no idea where they are supposed to be, and when. This Timetable is purely a guide!

Remember, our daily average winter month temperature is higher that the UK average summer month temperature.