Spurdog ©Peter Verhoog
Spurdog shark
Scientific name
Squalus acanthiasWhen to see
Present all year roundSpecies information
Statistics
Length: Up to 1.6 mWeight: Up to 9.1 kg
Average Lifespan: Can live for up to 75 years
Habitats
About
Also known as the spiny dogfish, the spurdog is a predator that feeds on bony fish, and sometimes even smaller sharks! It is a migratory species that spends the winter months in deep water, and the summer months in warm coastal waters.They often travel in groups which makes them an easier target for fisheries. It's difficult for these sharks to recover from overfishing, because they are very slow to reproduce, typically having 1 litter of pups every 2 years.
How to identify
The Spurdog shark has a pointed snout, large eyes, and spines in front of its dorsal fins. Its streamlined body is a grey/brown colour on top with a lighter belly and rows of white spots down its sides.Distribution
Found in the Irish Sea and Northeast Atlantic, and in temperate waters world-wide.In our area
Because the waters around NI are generally between 7 and 15 degrees Celcius, Spurdog are present throughout much of the year. They are most commonly found around Ballycastle and Red Bay, and pregnant females have also been seen along the Antrim coast between November and January. This suggests a pupping ground in the area. Critical areas such as pupping grounds need to be protected because this is an area that sharks live in when they are most vulnerable. As Spurdog sharks are categorised as Endangered in our local waters and are on the NI Priorty Species list we hope to be able to provide evidence through our tagging programme that will ensure spatial protection measures for them.
Did you know?
Female spurdog sharks have one of the longest pregnancies of any vertebrate, lasting between 18-22 months.Because the waters around NI are generally between 7 and 15 degrees Celcius, Spurdog are present throughout much of the year. They are most commonly found around Ballycastle and Red Bay, and pregnant females have also been seen along the Antrim coast between November and January. This suggests a pupping ground in the area. Critical areas such as pupping grounds need to be protected because this is an area that sharks live in when they are most vulnerable. As Spurdog sharks are categorised as Endangered in our local waters and are on the NI Priorty Species list we hope to be able to provide evidence through our tagging programme that will ensure spatial protection measures for them.