Sabertooth Blenny, Plagiotremus azaleus
The Sabertooth Blenny, Plagiotremus azaleus, whose common Spanish name is diente sable, is a species in the family Blenniidae, the Combtooth Blennies, known as borrachos in Mexico. Globally, there are ten species in the genus Plagiotremus, of which one is found in Mexican waters of the Pacific and is described here.
The Sabertooth Blennies have very elongated slender bodies. They have a broad brown mid-lateral band that runs from the snout, through the eye, to the caudal fin mid-body with a narrow off-white stripe immediately above. Their dorsal fin is black with a blue-white outer margin. They are off-white ventrally. Their head has a long conical protruding snout and a small inferior mouth with a large canine tooth projecting from each side of the lower front jaw and used for protection. Their anal fin base is low and long with two spines and 27 to 30 rays and four equally spaced black spots along its base and their caudal is concave with a long filament in the center. Their dorsal fin is low with a long base and twelve to fourteen spines and 31 to 35 rays; it is continuous and originates before the small gill openings. They do not have a lateral line. Their skin is smooth and without scales.
The Sabertooth Blennies are a non-migratory coastal species found demersal in very shallow waters and in weed-covered intertidal and subtidal rocky areas (including tidal pools) at depths up to 85 feet. They reach a maximum length of 10.2 cm (4.0 inches). They are highly territorial and will vigorously defend their habitat against intruders. They are known to inhabit empty tube-worm shells and to extend their heads from the opening. They are diurnal leaving their shelter to feed by relying on mimicry; they become darker and join schools of Cortez Rainbow Wrasse at levels of less than one per hundred for disguise to obtain potential access to prey fishes and to avoid predation or they hunt in packs of up to 100 individuals and attack larger fish such as Dog Snapper and Leopard Grouper. They primarily consume the skin of larger fish and eggs of a wide variety of species attached to the substrate. Reproduction is oviparous in distinct pairs with the females depositing eggs in protected areas. The eggs are sticky and adhere to the walls of the shelter; they are then fertilized by the males who guard them for two to three weeks until they hatch. They are present in all Mexican waters of the Pacific with the exception of the extreme northern portions of the Sea of Cortez. They are a small shallow-water species and very little is known about their behavioral patterns.
The Sabertooth Blenny is fairly easy to identify and cannot be confused with any other species due to its unique coloration patterns and large saber like tooth.
The Sabertooth Blennies are too small to be of interest to most and are normally a “catch-and-release.” They are known to nip at divers but overall are considered harmless to humans.