Porcupinefish

Diodon hystrix

•To puff up and to extend its toxic spines the porcupinefish has gills which act like a suction pump, they have a special sac with a muscular valve that holds the water, elasticated skin, they have no pelvic bones or ribs and their backbone and nerve cord can move out of the way as the water sac inflates their entire body.

•Members of this family spend a lot of effort in picking up chicks and in one species the male builds elaborate nests that look like underwater alien crop circles, just to impress the females.

this photo is from a species of pufferfish that lives in Japan