Spiny Dogfish Sharks

The warm summer waters off the West coast of Vancouver Island bring in a large number of shark species. The most common and abundant shark is the spiny dogfish shark (Squalus acanthias). This post was inspired by a unique scuba diving experience I had in about 40ft of water on a rocky reef in Barkley Sound. A curious female spiny dogfish shark about 1.25 metres long came swimming out of the murky depths. She circled back quite a few times and even swam right under me while I took these photos. Spiny dogfish sharks don't get much bigger than this one and they are often found in schools. However, this female shark was solitary and for the two days I dove the site and saw her both times. Quite a remarkable experience!

Spiny dogfish sharks are often underappreciated in the world of sharks. They are the most common and abundant sharks the North Pacific Ocean. Recreational fishers trolling for salmon in the summer months frequently catch these sharks. Their razor sharp teeth cut fishing line and the misconception that they are preying on salmon give them the bad reputation as a "trash fish". But this is no trash fish; these sharks possess some remarkable life history traits and behaviours. This is a highly migratory species where individuals tagged off the West coast of Vancouver Island were actually caught a year later off the coast of Japan! The spiny dogfish shark is also one of the most long-lived shark species, reaching an age of at least 80 years and females do not become reproductive until 35 years of age. The females also have an extremely long gestation period (fertilization to birth) - 22 months! This rivals the gestation period of the Asiatic elephant. A unique and fascinating member of the shark world - the spiny dogfish shark!