Sabertooth Blenny

Sabertooth Blenny, Plagiotremus azaleus

The Sabertooth Blenny, Plagiotremus azaleus, whose common Spanish name is diente sable, is a species in the Combtooth Blenny or Blennidae Family, known collectively as borrachos in Mexico. Globally, there are ten species in the genus Plagiotremus, one of which, this species, that  is found in Mexican waters of the Pacific.

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 12 to 14 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 a small shallow-water species and very little is known about their behavioral patterns.

In Mexican waters the Combtooth Blennies are present in all waters of the Pacific with the exception that they are absent from the extreme northern portions of the Sea of Cortez.

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.

Sabertooth Blenny, Plagiotremus azaleus, juvenile. Fish collected in the open ocean with a bait net, March 2010. Length: 5.1 cm (2.0 inches). Identification courtesy of Dr. Ross Robertson, Smithsonian Tropical Research Institute, Panama and reconfirmed by H.J. Walker, Scripps Institution of Oceanography, La Jolla, CA.

Sabertooth Blenny, Plagiotremus azaleus. Underwater photo taken in coastal waters off Kailua-Kona, HI, August, 2014. Length: 8.9 cm (3.5 inches). Photo courtesy of Bob Hillis, Ivins, UT.

Sabertooth Blenny, Plagiotremus azaleus. Fishprovided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, March 2011. Length: 4.5 cm (1.8 inches). Identification courtesy of Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.