Diamond Turbot

Diamond Turbot, Pleuronichthys guttulatus

The Diamond Turbot, Pleuronichthys guttulatus, whose common Spanish name is platija diamante is a member of the Righteye Flounder or Pleuronectidae Family, known collectively as platijas in Mexico. Globally, there are eight species in the genus Pleuronichthys, of which five are found in Mexican waters, all in the Pacific.

The Diamond Turbots have diamond-shaped, fusiform, and highly compressed bodies that are widest in the middle and have a depth that is 52% to 59% of standard length. They are dray gray to greenish with many small brown and blue spots. They are off-white on their blind side and bright yellow around their mouth. They have relatively large eyes on their right side with the top eye preceding the lower eye. They have a small asymmetrical mouth with teeth on both jaws. Their anal fin has 48 to 54 rays; their caudal fin is mid-sized and rounded with a wide base; their dorsal fin originates above the eyes and has 66 to 75 rays; their pectoral fins have 11 to 13 rays; and their pelvic fins are symmetrical. They have six to eight gill rakers. Their lateral line is straight and over the eyes with one branch extending under the lower eye and a longer branch extending under the dorsal fin.

The Diamond Turbots are found demersal in bays and lagoons from the surf zone over and within sandy and muddy bottoms at depths up to 150 feet. They reach a maximum length of 46 cm (18 inches). They are opportunistic well-camouflaged ambush predators that lie in wait half-submerged on the ocean floor consuming crustaceans and small fish.

The Diamond Turbots are found in Mexican waters of the Pacific from Magdalena Bay northward along the central and northwest coast of Baja and are present but rare in the northern half of the Sea of Cortez.

The Diamond Turbots can be confused with a series of other Righteye Flounders, including the Hornyhead Turbot, Pleuronichthys verticalis, the Ocellated Turbot, Pleuronichthys ocellatus, and the Spotted Turbot, Pleuronichthys ritteri, but all have elongated oval bodies.

From a conservation perspective, the Diamond Turbots are currently considered of Least Concern, having a wide distribution. They are caught primarily as a by-catch of deep water trawlers. They are very difficult to catch via hook and line due to their small mouths. They are a poorly documented and poorly studied species that is of limited interest to most.

Diamond Turbot, Pleuronichthys guttulatus. Fish caught via hook and line out of the Del Mar Lagoon, Del Mar, California, August 2017. Length: 12.5 cm (5.0 inches). Catch, photo, and identification courtesy of Ben Cantrell, Poway, CA.