May Elasmobranch of the Month: Spotted Ratfish
DID YOU KNOW: Ratfish are from the order CHIMAERA, which are in the class CHONDRICHTHYES – i.e. cartilaginous fish! That means they are close relatives of sharks!!!
General Description: This unusual looking fish has a copper/brown-silvery body with hints of gold and blue/greens. They also have white spots running across their heads and body! You might notice that it’s broad snout and face make it look like a mix between a duck and a rabbit! The spotted ratfish also has very large green eyes and can reach to just under 1 m in in length. They have permanent plate structures in their upper and lower jaws which are used to grind down their food.
DID YOU KNOW: Like the thresher shark, the caudal fin of the spotted ratfish can make up more than half of their total body length! Habitat The spotted ratfish are restricted in their distribution, were they are confined to the northeast waters of the Pacific. Mostly the spotted ratfish is a deep-sea species reaching depths of up to 913 m (Barnett et al., 2015), however can be found at very shallow depths too! This species loves to live close to the seafloor, swimming close to muddy/sandy bottoms or rocky reefs! Food Source/Diet As seafloor hunters, the spotted ratfish eats mostly animals that associate with the seafloor and include molluscs (clams), crustaceans (crabs) and bony fish. Remember, those teeth mentioned earlier? Well they help the spotted ratfish to crush through the hard shells of their prey! Status The spotted ratfish is listed as “Least Concern” on the IUCN Red List of Threatened Species. Threats While spotted ratfish are not a targeted species (Barnett et al., 2015), sometimes they are caught accidentally. Threats to this species include groundfish bottom trawl gear (Barnett et al., 2015) due to their preferred habitat (benthic-dwelling).
References Barnett LAK, Ebert DA and Dagit DD. 2015. Hydrolagus colliei. The IUCN Red List of Threatened Species 2015: e.T60191A80678052. http://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T60191A80678052.en. Accessed 16th May 2018.