Houndsharks

This month we’re taking a look at a few of the species from the houndshark family. The houndsharks, a.k.a. Triakidae, are a family of around 45 species. In this Creature Feature we’ll be looking at the Leopard Shark and Common Smoothhound.

Houndsharks are known for having two large, spineless dorsal fins, an anal fin and oval-shaped eyes with nictating eyelids. Animals with nictating eyelids have a third, clear, eyelid. This protects the eye whilst still allowing the houndsharks to be able to see. Houndsharks are small to medium in size, with adults ranging from around 37cm to 220cm. They’re one of the largest families of sharks. They are distributed throughout the world in warm and temperate waters. They predominantly feed on fish and invertebrates on the seafloor and in midwater.  

 

Leopard Shark

Confusingly named after a feline species, the Leopard Shark does indeed belong to the houndshark family. Its name comes from the unique saddle marks and spots that cover the species, resembling those of a leopard (as seen in the banner image).

It is one of the most common sharks found along the Pacific coast of North America. They are active, strong-swimming sharks. Sometimes spotted resting on sand among rocks. Leopard Sharks form large, nomadic schools with different species (such as the North Pacific Spiny Dogfish and Bat Rays.

The species is classified as Least Concern on the IUCN Red List of Threatened Species. Leopard Sharks are primarily caught by recreational anglers. But they are also taken as incidental catch in commercial fisheries. They are generally well managed by commercial fisheries. They are also popular in aquariums due to their distinctive markings and hardiness. The poaching of pups for the aquarium trade has been a significant problem.

SCIENTIFIC NAME: Triakis semifasciata

FAMILY: Triakidae (Houndsharks)

MAXIMUM SIZE: 180cm

DIET: Small sharks eat crabs, the siphons off clams and worms from the seafloor. Large sharks may eat fishes and even other smaller sharks.

DISTRIBUTION: Northeast Pacific – west coast of the United States from southern Washington to the Gulf of California (Mexico).

HABITAT:  Cool to warm waters. Most common on or near the seabed in bays and estuaries. Females give birth in water less than 1m deep.

CONSERVATION STATUS:

 

Common Smoothhound

A medium-sized, unspotted houndshark. The Common Smoothhound is often confused with the Starry Smoothhound which usually has white spots along its back. It’s also often confused with the Tope Shark. Smoothounds are so called because they will gather in large numbers, like a pack of dogs.

The Common Smoothhound is classified as globally Endangered on the IUCN Red List of Threatened Species. The species is classed as Vulnerable in Europe. It is targeted by fisheries across its range, both for sport and in commercial fisheries. The species is caught for food across the Mediterranean, European and West African fisheries.  There is often confusion between the Common Smoothhound and Starry Smoothhound. Starry Smoothounds often doesn’t have any stars/spots. So they are very similar in appearance. Genetic analysis is the most reliable way to distinguish smoothhounds.

SCIENTIFIC NAME:  Mustelus mustelus

FAMILY: Triakidae (Houndsharks)

MAXIMUM SIZE:  175cm

DIET:  Mainly crustaceans. Also cephalopods and bony fishes.

DISTRIBUTION:  Temperate east Atlantic. UK to the Mediterranean, Morocco down to South Africa and the Indian Ocean coast.

HABITAT:  Continental shelves and upper slopes. Usually 5-50m, but occasionally down to at least 800m.

CONSERVATION STATUS:

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Banner Image - ©Barbar Ash via Shutterstock

Image of Leopard Shark - ©ScubaZoo

Maps - ©Chris_huh, via Wikimedia Commons

Smoothound Illustration -©Marc Dando