by Brooklyn Bridge Park Conservancy on May 4, 2017
Two of the current stars of the Environmental Education Center’s 250-gallon tank look awfully familiar to many visitors. “Is that a pufferfish?” someone will ask. “And what about that little one? That’s another puffer! Do they really puff up? Are they poisonous?” This last question often comes a little breathlessly, with a hopeful inflection of the voice.
The two fish, about eight and five inches long respectively, are indeed puffers—or blowfish, or balloonfish, or bubblefish, or globefish, to list a few of the family’s many common names. They do puff up their bellies with water or air as a defense mechanism. The larger of the two demonstrated recently when it inflated its slender body to a sphere the size of a cantaloupe in a matter of seconds. The blow up was provoked by a nip from its smaller tank-mate and lasted for just a few precious seconds. Then it was all over.
To the chagrin of quite a few young visitors, northern puffers, the species in the Ed Center’s tank, are not poisonous—a quality that sets them apart from their closest relatives, which include some of the most toxic vertebrates. Quite to the contrary, northern puffers are considered a delicacy along the eastern seaboard, where larger specimens may make an appearance on a dinner plate under the name sea squab or chicken of the sea.
When not inflated, the northern puffer is unflatteringly described as club-shaped. Its body tapers from a large head with prominent eyes set near the top and a small beak-like mouth toward its fan-shaped tail fin, which serves mostly as a rudder. The fish is known as an agile, but slow swimmer. Lacking pelvic fins, it propels itself forward by moving pectoral, dorsal, and anal fins in sync with the tail fin. A would-be predator, however, is in for a surprise: what might look like an easy meal, quite suddenly transforms into an enormous prickly ball several times the size of the un-inflated puffer.
Much as they do in the wild, the Ed Center’s puffers spend most of their time in the open near the ground, watching their surroundings with huge eyes that move independently from each other. A closer look at the fish’s mouth reveals four prominent teeth, which are fused two and two in the upper and lower jaws. The four teeth are the family feature that gave rise to their scientific name, Tetradontidae.
Puffers are omnivorous and, depending on their size, they may use their teeth for crushing shells of small mollusks, crustaceans, and other invertebrates. At the Ed Center, the puffer diet consists of an assortment of clams, oysters, and other bivalve mollusks. Like many other fish species, the northern puffer has a darker back and a light-colored underside, which helps to camouflage the fish when seen from above against the darker bottom and when seen from below against the sunlit surface. Like their other tank-mates, the two northern puffers come from the local New York waters. They will stay at the Ed Center until early summer when they will be released into the brackish waters of the East River.