A catshark that is a dogfish

Found on Brighton Beach: a small-spotted catshark (Scyliorhinus canicula) often called a dogfish. No, it’s not sunbathing, it’s dead, probably having been scavenged (yet not consumed). Sunlight does, though,  cast a warm glow on the fish and its pebble resting place.

The slender, elongated body has a pale, creamy underside and is covered in small, dark spots. Its gills can be seen through the open mouth, and its pectoral and dorsal fins are clearly visible. The tail appears slightly curled.

The small-spotted catshark is a small shark, so named due to the dark spots and blotches covering its skin. Individuals typically grow to around 60-70 cm in length, though some can reach up to one metre. Like all sharks they have very rough skin, covered in hard ‘dermal denticles’ - which literally means ‘tiny skin teeth’. If rubbed the wrong way, the fish feel very coarse like sandpaper but this provides them with an effective chain-mail like protection. 

Catsharks are predators and feed on crabs, molluscs and other small fish. When threatened, they curl up into a donut shape - probably to look bigger and harder to eat! They are highly common around the UK, harmless to humans, and live in sandy, gravelly, or muddy seabeds. As with all sharks and rays, their egg cases are known as mermaid’s purses; these have tendrils that anchor them to seaweed or rocks until they hatch.

What about this odd confusion of names? Wikipedia gives several other names for the small-spotted catshark: sandy dogfish, lesser-spotted dogfish, rough-hound and morgay (in Scotland and Cornwall). In the early days of animal classification, naturalists like Linnaeus initially grouped most sharks under the Squalus genus (Latin for shark). Over time, scientists refined their classification, moving this particular species into the Scyliorhinus (catshark) genus in the early 1900s. However, fishermen have traditionally used the term ‘dogfish’ for any common or abundant small sharks, regardless of their actual scientific classification. 

So, if you like, you can be both a dog(fish) person AND a cat(shark) person at the same time - though not a catfish, which is something entirely different!