{{Speciesbox | name = Swell shark | image = Swell Shark, San Clemente Island, California.jpg | image_caption = | status = LC | status_system = IUCN3.1 | status_ref = | genus = Cephaloscyllium | species = ventriosum | authority = (Garman, 1880) | range_map = | range_map_caption = | synonyms = *Scyllium ventriosum (Garman, 1880) Cephaloscyllium uter (Jordan & Gilbert, 1896)Catulus uter (Jordan & Gilbert, 1896)) }} The swell shark (Cephaloscyllium ventriosum) is a catshark in the family Scyliorhinidae. It is found in the tropical and subtropical eastern Pacific Ocean from between central California to southern Mexico, with an additional population off the coast of Chile. As a defense, the swell shark is able to expand to approximately double its regular size by swallowing water. Taxonomy When discovered in 1880, the swell shark was first described as Scyllium ventriosum, but was later changed to Cephaloscyllium ventriosum. The genus name comes from the Greek word kephale, which means "head", and skylla, which means a certain kind of shark. The species name comes from the Latin word ventrĭōsus'', which means "large-bellied". The species name refers to its ability to enlarge itself by taking in water. Distribution and habitat The swell shark is found in the eastern Pacific Ocean, from the central California coast to southern Mexico. There is an additional population off the coast of Chile. It can be found between the depths of 5 m and 457 m, but is most common between 5 m and 37 m. Swell sharks are often found over algae-covered rocky bottoms where it hides in crevices during the day. Description Swell sharks are typically around 90 cm in length, with a maximum length of 110 cm. They have flat, broad heads with large gold eyes that have nictitating eyelids. Swell sharks have a yellow-brown coloration, with brown and white spots. The spots cover their underside, but are not present on their fins. Usually the younger sharks are lighter in color than the adults. The gills of a swell shark are usually very small and tight. Every swell shark has around 55–60 teeth. Teeth typically have three smooth cusps, but can have as many as five cusps. The middle cusp is the longest. Ecology Swell sharks are nocturnal and sleep in rock crevices during the day, where their appearance allows them to be camouflaged. They are very sociable and are commonly seen sleeping next to or