The Spiny Dogfish is a small shark frequently encountered in Mediterranean waters. It features an elongated, torpedo-shaped body with a grey-brown back and a white belly. Although it is a shark, it is harmless to humans, but it is dangerous due to its defensive spines. In the Mediterranean, two main species are distinguished:

Piked Dogfish (Squalus acanthias): Easily identified by the small, white spots scattered across its back and sides.

Longnose Spurdog (Squalus blainvillei): Lacks spots and has a uniform grey or brown colouration. This is the species most commonly found in the deeper waters of the Mediterranean.

This shark moves across a wide range of depths, from shallow coastal waters of 5 to 10 metres down to depths exceeding 1,000 metres. It primarily lives near the seabed but frequently swims higher into the water column to hunt for prey.

It is a small-bodied shark. The common length ranges from 50 centimetres to 1 metre, with a weight of 1-3 kilograms. However, females grow larger than males and can reach up to 1.5 metres, sometimes weighing up to 9 kilograms.

The reproductive method of this species is remarkable. It is ovoviviparous, meaning the mother retains the eggs inside her body until they hatch and then gives birth to fully formed young. Most notably, the gestation period is one of the longest in the animal kingdom, lasting between 18 and 22 months. It gives birth in winter to between 1 and 20 young, which are ready to hunt immediately upon birth.

Fisheries & Economic Value

It is usually caught incidentally as bycatch in nets, bottom longlines, and trawls. Recreational anglers often catch it using handlines in deep water. While its commercial value is relatively low in some regions, it is highly sought after in countries like the United Kingdom for the famous "fish and chips." Due to its slow reproductive rate, it is considered a vulnerable species and is at risk from overfishing.