Language English The Gulf of St. Lawrence Photo: Biodôme Photo: Biodôme Photo: Biodôme OngletsDescriptionDistinguishing features The spiny dogfish has five gill slits on either side of its body, just in front of the pectoral fin. It has two dorsal fins and, in front of each of these, a sharp spine. It does not have an anal fin. Its slate grey back and flanks are marked with faint white spots. Reproduction The female reaches sexual maturity at 12 years, on average, and the male at 6 years. Fertilization occurs internally. This fish is ovoviviparous, meaning that the eggs develop within the female's uterus. The number of eggs ranges from 2 to 15. The gestation period is 22-24 months, the longest for any vertebrate. Diet Spiny dogfish mainly eat prey that are small enough to be swallowed whole, primarily fish such as herring and capelin, but also squid, shrimp, polychaete worms and sea anemones, etc. Predators Their main enemies are seals and larger sharks. Habitat These bottom-dwelling sharks live in relatively cold water, at temperatures ranging from 6 to 15°C. They are found at depths of up to 360 m, as well as in shallow water. Ecology, behaviour They often live in schools, particularly during the breeding and migration season. Both these activities take place in winter, when spiny dogfish leave the St. Lawrence Estuary and migrate to the coast off North Carolina. French nameAiguillat commun Scientific nameSquallus acanthiasPhylumChordataClassChondrichthyes (cartilaginous fish)OrderSqualiformesFamilySqualidaeSizeMaximum length of female: 120 cm; maximum length of male: 90 cmWeightMaximum weight of female: 7 kgLife spanFemale: 40 years; male: 35 yearsStatusVulnerable (IUCN - 2006); special concern (Cosewic - April 2010).