The humpback smooth-hound (''Mustelus whitneyi'') is a

houndshark Houndsharks, the Triakidae, are a family of ground sharks, consisting of about 40 species in nine genera. In some classifications, the family is split into two subfamilies, with ''Mustelus'', '' Scylliogaleus'', and '' Triakis'' in the subfamily ...

of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Triakidae. It is found on the

continental shelves A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

of the

tropical The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

southeast

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, from

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

to southern

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, between

latitude In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...

s 3° S and 54° S, at depths between .

Description

The humpback smooth-hound is a small shark growing to a length of up to . It has a sturdy body with a moderately long, broad, sharply angled snout and large eyes, set widely apart. The mouth is fairly long and the upper lip furrows are longer than the lower ones. The teeth have a main pointed cusp and sometimes smaller subsidiary ones. The first dorsal fin is approximately triangular and the trailing edge is fringed with bare, dark-coloured collagen rods known as ceratotrichia. The pectoral fins are large and the pelvic fins moderately so. The caudal peduncle is short and the lower lobe of the tail fin is hardly curved in adults. The colour of this shark is plain grey or greyish-brown without any spots or barring.

Distribution

The humpback smooth-hound is found in the eastern Pacific Ocean off the coast of Peru and Chile, between 1°N and 45°S. Its depth range is between but it is most common between . It is found near the seabed, often on rocky shores, where it feeds on small fish and crustaceans such as

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s and

mantis shrimp Mantis shrimp, or stomatopods, are carnivorous marine crustaceans of the order Stomatopoda (). Stomatopods branched off from other members of the class Malacostraca around 340 million years ago. Mantis shrimp typically grow to around in lengt ...

s. It is

viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the m ...

and the females bear litters of five to ten young which are about long when born.

Status

The humpback smooth-hound is fished for human consumption in Chile but more particularly in Peru, where it is more common. Along with the

spotted houndshark The spotted houndshark, ''Triakis maculata'', is a houndshark of the family Triakidae found in tropical waters in the eastern Pacific Ocean off the coast of South America. It usually grows to a length around . The reproduction of this houndshark ...

(''Triakis maculata'') and the

speckled smooth-hound The speckled smooth-hound (''Mustelus mento'') is a houndshark of the family Triakidae. It is found on the continental shelf of the eastern Pacific, between latitudes 0° and 54° S, at depths between . It can reach a length of . Collectively ...

(''Mustelus mento'') it is known as "tollo" in its local fisheries, and of the three species it is the humpback smooth-hound that is the main target of the tollo fishery in Peru. Landings averaging 11,000 tons of tollo per year were made in that country between 1965 and 1989, but quantities caught diminished thereafter. A minimum size requirement of was set in 2001 but was pitched so low as to have limited conservation effect. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN) has rated the status of the humpback smooth-hound as being critically endangered due to overexploitation.

References

External links

* {{DEFAULTSORT:smooth-hound, humpback humpback smooth-hound Western South American coastal fauna humpback smooth-hound