noun
blotchy swell shark
A species of catshark (Cephaloscyllium umbratile) found in the northwestern Pacific. The Japanese name literally means 'seven-day shark', possibly from an old belief about its gestation or behavior.
水族館でナヌカザメを見た。
I saw a blotchy swell shark at the aquarium.
The name ナヌカザメ (七日鮫) literally means 'seven-day shark'. The exact origin is uncertain, but it may derive from a folk belief that the shark gives birth after seven days, or from its pattern of spots.