Science Snippet: Blennies

A Fang Blenny peeks out of a hiding place in coral. The arrows show the pair of fangs on the lower jaw. Photo by Jeff Mullins.

“Blennies” are common ocean fish that may reach three inches in length. They belong to a large group made up of many species. One of these groups, called the “Fang Blennies,” is unusual in that the fish have two fangs on their lower jaws (see figure). The function of these fangs is protection, for these small fish could make a nice appetizer for larger fish, such as the grouper. However, predators are discouraged because the feisty little fish can bite and use its fangs to inject venom into them. The venom appears to cause a drop in the predator’s blood pressure sufficient to disorient it and lose interest in the blenny. Analysis of the venom shows that it contains three chemicals, one similar to scorpion venom and an opioid. Strangely enough, experiments with mice suggest the venom does not cause pain, as with most other venoms. (science daily.com, Mar. 30, 2017; Casewell et al, 2017, cell.com/current-biology/full text, Mar. 30)