Table of Contents
The members of these two families are so closely allied one to the other, not only anatomically but in general appearance, that they may be described as a unit. They have only one dorsal fin (the soft-rayed), the spiny dorsal being obsolete, and they have no ventral fins. Their gill openings are reduced to short slits like those of their allies, the triggerfishes and filefishes (pp. 520 and 521); their teeth are fused into cutting plates; and they have no scales. The two families are separable by the structure of the teeth, as described below in the accounts of the two species concerned, and by certain anatomical characters.
All of them are capable of inflating their bellies to balloonlike proportions with air or with water, if annoyed, and of deflating at will. And it is a matter of general interest (though not touching [page 526] the Gulf of Maine directly) that the flesh of some of the species of puffers, and perhaps of all of the porcupine fishes, is poisonous.
Both groups are warm-water fishes. One species of puffer reaches the southwestern part of the Gulf rather commonly; and one porcupine fish has been reported there as a stray from the south.