Spiny Dogfish - Squalus acanthias

WHAT TO LOOK FOR
A small schooling shark with a spine in front of each dorsal fin.

COLOR
Gray or brownish on top with irregular white spots, pale gray or white below.

SIZE
At birth, the shark is 8 to 12 inches [20 to 30 cm] in length. Adults average 30 to 40 inches [75 to 105 cm] in length.

HABITAT
Found from the surface to depths of 2,400 feet [730 m]..

DISTRIBUTION
Temperate oceans.

BIOLOGY
General - Extremely well studied: Previously one of the most abundant shark species, and the most important commercial species. The sharks form groups of hundreds of individuals of the same sex and size. This species has a long life span (70 to 100 years), and grows slowly (2.7 to 3.3 mm per year).
Prey - The shark is an opportunistic feeder eating whatever prey is abundant. In general their diet is comprised of small fishes but it will also eat invertebrates.
Reproduction - Oviparous. Late sexual maturity (females 12-23 years, males 6-14 years). Gestation period is 18 to 24 months and females bear litters averaging 6 pups.

BEHAVIOR
Typically found in packs or schools of individuals of the same size and sex, which stay together as they grow. This results in fishers maintaining catches that target the largest individuals despite stock depletions. Exploited populations become male-biased with reduced pup production as large females are removed.

STATUS
Globally Vulnerable. Its slow growth, late maturity, longevity and low reproductive capacity make the species highly vulnerable to over-exploitation, particularly since large pregnant females are usually targeted. The high demand for spiny dogfish meat, primarily in Europe, drives targeted fisheries and international trade. In the UK, its meat is used for ‘fish and chips’. Spiny dogfish products are also used for liver oil, pet food, fertilizer, and their fins are used for inexpensive versions of shark fin soup. Some stocks are now very seriously depleted or have collapsed, and catches are declining steeply. Scientists predict that stringent recovery programs could rebuild the population to healthy, fishable levels in approximately 20 years. In 2007, at CITES CoP14, the spiny dogfish was proposed for Appendix II, but the proposal failed to achieve the 2/3rds majority vote required for the listing. The Appendix II listing would regulate international trade and assist efforts to reverse the unsustainable exploitation of the species. In 2010, at CITES CoP15, the species was again proposed for Appendix II by Palau and Sweden, but the proposal failed to achive sufficient votes for the listing.