Spiny dogfish

How it lives

It grows slowly and lives a long time. Atlantic fish live 35 to 40 years, but Black Sea studies report a maximum age of about 20 years. It bears live young. Pregnancy lasts 18 to 24 months in the Atlantic and is reported to be about half as long in the Black Sea. Black Sea studies give 8 to 13 pups per litter on average, and a 2006 conservation briefing cites about 32. Females reach maturity at about 88 to 103 cm in Black Sea studies. To give birth, females come to coastal shallows at about 10 to 30 m in spring and autumn, while males stay slightly deeper.

Where it goes

In the Black Sea it lives across the whole shelf in water of about 6 to 15 degrees C and makes long migrations. In autumn it travels towards wintering grounds of anchovy and horse mackerel near the Crimean, Caucasus and Anatolian coasts, then spreads out over the shelf. Spring and autumn breeding movements bring females towards the coast.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

Globally the spiny dogfish is Vulnerable (IUCN, assessed 2019) and its population is decreasing, mainly from fishing. A stock assessment for the Black Sea showed a fall of about 60% between 1981 and 1992, according to a 2006 conservation briefing, which also said the IUCN then considered the Black Sea population Endangered. A current separate Black Sea rating was not confirmed in the sources opened. Bulgaria is among the countries within its range.