Smooth dogfish
Encyclopedia
The dusky smooth-hound or smooth dogfish, Mustelus canis, is a species of hound shark
Hound shark
Houndsharks are a family, Triakidae, of ground sharks, consisting of about 40 species in 9 genera. In some classifications, the family is split into two sub-families, with Mustelus, Scylliogaleus, and Triakis in sub-family Triakinae, and the remaining genera in sub-family Galeorhininae.Houndsharks...

, family Triakidae. This shark is an olive grey or brown, and may have shades of yellow or grayish white. Females live to 16 years and males have a life span of 10 years. Mustelus canis was the first shark recognised to have viral infection.

Size and growth

Length for the dusky smooth-hound is up to 1.5 m (60 inches), with a maximum weight of 12 kg (27 lb). Dusky smooth-hound reach maximum size at 7 or 8 years of age. Average size of this shark
Shark
Sharks are a type of fish with a full cartilaginous skeleton and a highly streamlined body. The earliest known sharks date from more than 420 million years ago....

 is approximately 1.2 m (48 in). This species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 grows quickly, with males reaching maturity at 2 or 3 years of age, and females at 4 to five years of age.

Habitat

A common resident in bays, and other inshore waters, the dusky smooth-hound prefers shallow waters of less than 18 m (60 ft) in depth but may be found to depths of 200 m (650 ft). This species has also been found on occasion in freshwater although it is unlikely they can survive freshwater for extended periods of time. The dusky smooth-hound migrates seasonally, moving north in the spring and south in the autumn. It is primarily a nocturnal species.

Food

A scavenger and opportunistic predator, the dusky smooth-hound feeds primarily on large crustaceans, including lobster
Lobster
Clawed lobsters comprise a family of large marine crustaceans. Highly prized as seafood, lobsters are economically important, and are often one of the most profitable commodities in coastal areas they populate.Though several groups of crustaceans are known as lobsters, the clawed lobsters are most...

s, shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...

, and crabs, as well as small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, mollusks and small fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

 that have been injured. The flat, blunt teeth of the dogfish are used to crush and grind these prey items which have tough outer body coverings. Small fish that are preyed upon by the dusky smooth-hound include menhaden
Menhaden
Menhaden, also known as mossbunker, bunker and pogy, are forage fish of the genera Brevoortia and Ethmidium, two genera of marine fish in the family Clupeidae.-Description:...

 and tautog
Tautog
The tautog or blackfish also known as the "poor-man's lobster" , Tautoga onitis, is a fish of the wrasse family found in salt water from Nova Scotia to Georgia...

. Young dusky smooth-hound feed on small shrimps, worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...

s, and crabs.

Reproduction

Mating occurs throughout most of the dusky smooth-hound's range from May through July. Following a gestation period of approximately 10 to 11 months, a litter numbering as few as 4 and as many as 20 is born during late spring or early summer. Larger females tend to have larger litters.

Importance to humans

In certain areas, the flesh of dusky smooth-hound is marketed as fresh or dried salted for human consumption. The dusky smooth-hound is often used as a laboratory animal and in public display at aquariums.
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