Planehead Filefish

Planehead Filefish, Stephanolepis hispidus

The Planehead Filefish, Stephanolepis hispidus, whose common Spanish name is lija aspera, is a species in the Filefish or Monacanthidae Family, known as lijas in Mexico. This fish is also known as the Sargassum Filefish. Globally, there are only five species in the genus Stephanolepis, three of which are found in Mexican waters, all in the Atlantic.

The Planehead Filefish have deep laterally compressed bodies. They are a mottled pale brown, olive or green color on a light colored background with two darker brown blotches and streaks on their sides. They are covered with minute scales and their skin is rough to the touch. Their head has an elongated snout with a terminal mouth giving them a concave profile. They have large yellow eyes that are set high on their head. Their anal fin is without spines and has 30 to 35 rays. Their caudal fin is large and fan-shaped with two darker colored bands. Their dorsal fin has two spines, the first being strongly barbed and the second being minute, and 29 to 35 rays with a long base. The second dorsal ray in males is elongated. Their pectoral fins are small; they do not have pelvic fins.

The Planehead Filefish are benthic, being found at depths up to 980 feet. They inhabit reefs and sandy and muddy sea floors and are often associated with Sargassum Seaweed. The Planehead Filefish reach a maximum length of 27 cm (11 inches) but more commonly measure around 17 cm (6.7 inches). They spawn during summer months and have a lifespan of up to three years.

The Planehead Filefish have a wide global distribution being found in the Eastern Atlantic (Angola and the Canary Islands) and the Western Atlantic (Canada to Uruguay). In Mexican waters they are found throughout the Gulf of Mexico.

The Planehead Filefish is easily confused with the Pygmy Filefish, Stephanolepis setifer (straight head profile; anal and dorsal fins with 27 to 29 rays). They are also similar to several of the juvenile Triggerfish, which have three dorsal spines versus two for the Filefish.

The Planehead Filefish are used for human consumption in some cultures. They became a targeted species in the 1980’s and are generally caught in fish traps. They are currently suffering from overfishing in parts of their range. They are also used in the aquarium trade and are available for purchase over the internet.

Planehead Filefish, Stephanolepis hispidus. Fish caught from coastal waters off Key West, Florida, August 2014. Length: 22 cm (8.7 inches). Catch, photo and identification courtesy of Dean Kimberly, Atlanta, GA.

Planehead Filefish, Stephanolepis hispidus. Fish caught off the Dania Pier, Dania, Florida, December 2015. Length: 18 cm (7.1 inches). Catch, photo and identification courtesy of George Brinkman, Guelph, Ontario, Canada.