This vulnerable shark appears to have a hump on its back

The Humpback smoothhound (Mustelus whitneyi) is a shark belonging to the family Triakidae. It is found on the continental shelves of the tropical southeast Pacific, from Peru to southern Chile. This shark like in its name appears to have a humped back. It is currently vulnerable.


Family: Triakidae – Houndsharks

Genus: Mustelus 

Species: whitneyi


Phylum– Chordata

Class– Chondrichthyles


Common NameGround Sharks

Family– Triakidae

Common NameHoundsharks




Average Size and Length: They are born around 25 cm/9.8 inches. Mature males are less than 68 cm/2.2 feet at maturity and the maximum recorded is at least 87 cm/2.8 feet.

Teeth and Jaw: The mouth is fairly long, and the upper furrows are longer than the lower furrows. It has strongly cuspidate teeth. It seems there is a main pointed cusp, with some smaller ones.

Head: It has a moderately long, broad, sharply angled snout and large eyes, set widely apart.

Tail: The caudal peduncle is short. The lower lobe of the tail fin is hardly curved in adults.

Demographic, Distribution, Habitat, Environment and Range: The Humpback smoothhound can be found in the tropical southeast Pacific from Peru to South Chile (3° S and 54° S or 1°N and 45°S, 83°W – 70°W). They are found on the continental shelf between 52-692 feet, but mostly between 230-328 feet. They seem to prefer the rocky bottoms around islands. They are considered demersal.

Diet: They eat crabs and mantis shrimp mostly and also small bony fish.

Aesthetic Identification: The Humpback smoothhound is a grey, unspotted shark that is somewhat stalky, giving its name and appearance to look like it has a humped back. There is a dark margin of bare ceratotrichia on the trailing edges of the dorsal fins. This gives them a frayed appearance. The pectoral fins are large and the pelvic fins of moderate size.

Biology and Reproduction: They are viviparous having five to ten pups per litter.

Behavioral Traits, Sensing and Intelligence: Unknown.

Humpback Smoothhound Future and Conservation: They are currently vulnerable. They are common off the coast of Peru. They have been fished with other tollo, like the Spotted houndshark and the Speckled smoothhound in Peru for human consumption. Around 11,000 tons of tollo per year were made in Peru between 1965 and 1989, but quantities caught diminished afterwards. A minimum size requirement of 60 cm/ 1.9 feet was set in 2001 but was pitched so low as to have limited conservation effect.

Humpback Smoothhound Recorded Attacks on Humans: Not a threat to humans.