Migratory patterns of Pacific spiny dogfish are not well understood. Recreational fishing accounts for an insignificant portion of the spiny dogfish harvest. Bottom trawlers and sink gillnets are the primary equipment used to harvest spiny dogfish. Squaliformes is an order of sharks that includes the smooth dogfish and spiny dogfish. The gestation period for spiny dogfish is normally 18 to 24 months. This makes the Northeast Pacific spiny dogfish the longest living out of all dogfish. They do not have any fin spines, unlike the spiny dogfish. Gestation period and pupping seasonality of female spiny dogfish ("Squalus acanthias") off southern New England. Pacific spiny dogfish prefer to be in temperatures ranging from . The Pacific spiny dogfish has a unique system of ventilation. Migration patterns of spiny dogfish (squalus acanthias) in the north Pacific Ocean. Reproduction of female spiny dogfish, "Squalus acanthias", in the Oslofjord. The Pacific spiny dogfish also has a special feature called a spiracle. The Pacific spiny dogfish are small and skinny members of the family Squalidae. The spiny dogfish has one of the longest lifespans at more than 100 years.