Life photo meme: Swell shark

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Carcharhiniformes

Family: Scyliorhinidea

This is a swell shark, or Cephaloscyllium ventriosum. They are common inhabitants of the kelp forests; found during daylight hours laying about on the floor. Swell sharks have a neat trick of inflating by gulping down water or air. They can use this technique to wedge themselves into rocks, making it impossible for predators to get them out. There is a really awesome website describing all of the research done on them here. I am going to summarize some of it, but be sure to check it out for the full detail.

Swell sharks lay eggs, which can take up to a year to hatch. They are poor swimmers and nocturnal, but don't use light cues to initiate activity. Instead they relay on internal cues, general going for a 12 hours of sleep, 12 hours of activity. When they hunt, they use two different tactics: it waits until the fish is close to its head, than sucks it into its mouth with a "gulp", or it slowly opens its mouth and waits till a fish drifts in.