dogfish shark (Squalus acanthias), also known as tollo de chub or galludo is one of the most common and abundant sharks in the world. Belonging to the shark family. The best known and most studied species of dogfish is the spiny shark.

Dogfish shark

Dogfish shark

Features

It is a small shark, it is just over 1 meter long, it is characterized by a small anal fin. Although the most characteristic are its two spines located on its back, a spine in front of each dorsal fin and stingers on its back that are slightly poisonous and that it uses to defend itself. It has a gray body, with a lighter color on its belly, with small whitish markings on its back. It has large eyes and a small mouth, unlike many other sharks.

Habitat

It can be located anywhere in the world through the Pacific, Atlantic and Indian oceans. They tend to preferably inhabit the warm and coastal waters, but it has frequently been possible to fish in the cold waters of the southwest of South America (subantarctic phytogeographic domain)

Food

The dogfish is essentially carnivorous. Their diet is mainly based on other fish, crustaceans, and squid. Although they have also been seen hunting octopus and other sharks.

Predators

Because of their size, aggressiveness, and poisonous beaks, the only predators that dogfish have are larger sharks and humans. It is rarely preyed upon by the killer whale.

Reproduction

Spiny dogfish, like other sharks are ovoviviparous animals, does not deposit the eggs in the water, they incubate them and breed inside the female and come out when they can live alone. Its gestation time can last up to two years (it has the longest gestation of vertebrate animals). In a single gestation she can give birth to up to 15 young.

State of conservation

Once considered the most abundant species of elasmobranch (sharks and rays) in the world, the spiny dogfish has suffered serious population declines throughout its range, especially in the Northeast Atlantic, where population declines of 95% and where it is now considered critically endangered.

The main threat is commercial overfishing with various gears, but especially with trawl gears, which can also damage the habitat of the dogfish. They were a valuable fishery, in high demand in Western Europe. In the UK, like other shark species, the spiny shark was commonly sold in fish and chip shops as 'rock salmon'. Like other elasmobranchs, dogfish are slow to mature, long-lived, and have low reproductive rates, making them highly vulnerable to overexploitation.

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