Little Tropical Fish: with a Big Bite poisonous. It is a small fish, only a couple of inches long, and its bright colors makes pop into the Pacific coral reef calling home. The first thing that makes this curious fish is the striking pair of large lower canines than sports. But when it is attacked by a predator, this fish, part of a group called Blenios Fang, does something even stranger. A predator who puts this fang blenny in his mouth would experience a violent shaking of the head, according to George Losey, a zoologist who observes this species of fence in a series of feeding experiments in the 1970s. Then the predator would open its Jaws and gills. The little blenny would be swimming away, unscathed. A study published Thursday in Current Biology magazine now uncovers the details of the unusual fish defense mechanism: Unlike most poisonous fish, which inject toxins through their fins, cannabis blenios inject venom through their sting . In addition, fang blenny venom does not seem to produce potent pain, at least in mice. Instead, there is a sudden drop in blood pressure, which can temporarily stun predators. This is one of the most in-depth studies of how the venom of any particular group of fish works. The study authors took a multiple approach to studying venomous canine blennies. First, we obtained images of the blenned jaws of fangs coming from across the Pacific and the Indian Ocean to confirm what scientists suspected for a long time: Not all blennies have fangs of venom at the base of the teeth.