SQUALIDAE DOGFISH SHARKS
The Squalidae, or common English name Dogfish sharks are a family of sharks in the order Squaliformes. They have two dorsal fins, each with smooth, un-grooved spines, but no anal fin. The pelvic fins are smaller than the pectoral fins. The caudal peduncle has strong lateral keels and the caudal fin does not have a subterminal notch. Both genus belonging to this family have several slight aesthetic differences.
Dogfish sharks are characterized by teeth in upper and lower jaws similar in size; a caudal peduncle with lateral keels; the upper precaudal pit usually is present; and the caudal fin is without a subterminal notch. The livers and stomachs of the Squalidae contain the compound squalamine, which possesses the property of reduction of small blood vessel growth in humans; however, real-use treatments for cancer currently failed a phase III trail in 2018.
Dogfish sharks can be found worldwide in temperate, boreal and tropical seas. Some species occur from intertidal zone down to deep depths. Some species may also occur solitary and others in groups. Squalidae are ovoviviparous.
There are 3 currently known species in the genus Cirrhigaleus and 27 currently known species evaluated here in the genus Squalus.