Scientific Name: Squalus acanthias
Ideal Temp: 45-55°F (7-13°C)
Environment: Inshore, Nearshore, Surf
Technique: Bottom Fishing, Chunking
Lure Type: Bottom Rig
World Record: 7.14 kg (15 lb 12 oz) Kenmare Bay, Co. Kerry, Ireland
The spiny dogfish, Squalus acanthias, is one of the best known of the dogfish which are members of the family Squalidae in the order Squaliformes. While these common names may apply to several species, Squalus acanthias is distinguished by having two spines (one anterior to each dorsal fin) and lacks an anal fin. These dogfish are found in inshore and offshore waters over the continental shelf to depths of 2950 feet (900 m).
The spiny dogfish has dorsal spines, no anal fin, and white spot along its back. The caudal fin has asymmetrical lobes, forming a heterocercal tail. The species name acanthias refers to the shark's two spines. These are used defensively. If captured, the shark can arch its back to pierce its captor. Glands at the base of the spines secrete a mild poison.
Males mature at around 11 years of age, growing to 80–100 cm (2.6–3.3 ft) in length; females mature in 18–21 years and are slightly larger than males, reaching 98.5–159 cm (3.23–5.22 ft). Both sexes are greyish brown in color and are countershaded. Males are identified by a pair of pelvic fins modified as sperm-transfer organs, or "claspers". The male inserts one clasper into the female cloaca during copulation.
Spiny dogfish are fished for food in Europe, the United States, Canada, New Zealand and Chile. The meat is primarily consumed in England, France, the Benelux countries and Germany. The fins and tails are processed into fin needles and are used in less expensive versions of shark fin soup in Chinese cuisine. In England this and other dogfish are sold in fish and chip shops as "rock salmon" or "huss", in France it is sold as "small salmon" (saumonette) and in Belgium and Germany it is sold as "sea eel" (zeepaling and Seeaal, respectively). It is also used as fertilizer, liver oil, and pet food, and, because of its availability, cartilaginous skull, and manageable size, as a popular vertebrate dissection specimen, in both high schools and universities.
Dogfish have earned a bad reputation among fishermen for their voracious appetites. They are known to drive off commercially caught fish including mackerel and herring, while consuming large numbers of them. Spiny dogfish have been observed biting through nets to get at fishes, releasing many of them in the process. Schooling pelagic fishes make up the majority of the diet of the spiny dogfish. These include herring, menhaden, capelin, sand lance, and mackerel. Other consumed species include wolffish and flatfishes, as well as squid, jellyfish, shrimps, crabs, octopus, and sea cucumbers.