1. Swellshark - Cephaloscyllium ventriosum

    Native to coastal waters in the Eastern Pacific from central California to Chile, the swellshark is a nocturnal species that rests among the rocky reef during the day and hunts fish, crustaceans and molluscs at night. Adults reach an average length of about 3ft and are oviparous, with the female depositing only two egg sacks at a time among a rocky, algal-covered habitat. When threatened, it bends its body and grabs its caudal fin in its mouth before swallowing a large amount of water to double its size, making it difficult for a potential predator to bite or remove it from a crevice. It is also able to do this same behaviour with air if brought to the surface, and will let out a dog-like bark when expelling the swallowed water or air.