PUFFERFISHES - Tetraodontidae
Although confused by some with  Porcupinefish (Diodontidae [="two teeth"]),  Pufferfish (Tetraodontidae [="four teeth"]),differ in their beak-like teeth are not  fused, with a noticable groove and lack obvious spines on the body. Both families have the ability to enlarge themselves as a predator deterrent.

Chiefly marine. Many going into and inhabiting brackish and freshwater.

Naked or with short prickles in belly.  Capable of greatly inflating themselves with water. Attains 90 cm maximum length.

Some puffers contain tetraodotoxin, especially in the viscera; in the gonads of some during spawning season. European Community legislation prohibits trading with puffer fish products. Some species seem to consume about everything, whereas others have preferences for certain invertebrates or algae.

Demersal eggs are laid in a nest and presumably defended.

Jaw teeth fused but separated by a median suture in each jaw, giving rise to 4 fused teeth. Opposite dentaries and premaxillaries separate at midline. Usually 7-18 dorsal soft rays. Anal soft rays usually 7-18. Ribs and epipleurals lacking. Moderately forked to rounded caudal fin. Principal caudal fin rays 10; procurrent rays lacking.
Greek, tetra = four + Greek, odous = tooth, teeth
Sphoeroides testudineus
Canthigaster rostrata