Greater Sand Perch, Diplectrum maximum: The Greater Sand Perch is the largest of the nine sand perches found in Mexican waters and reported to reach 37 cm (14.6 inches) in length which is a full 2.5 inches longer than the second largest sand perch. We have collected a fish that was 40.2 cm (15.8 inches) extending the known maximum length for this species.
The Greater Sand Perch has an elongated body with the upper two-thirds of the head and body being dark grey-brown. The belly is white. A key to identification of the Greater Sand Perch is that the angle of the preoperculum is a narrow, round pointed bony spur with four to eight large spines. There is a large dark blue-gray blotch on the upper edge of the operculum and the second and third dorsal spines are of equal length.
This fish species is found at depths of between 10 and 400 feet in the water column over sandy and muddy bottoms. As it is a relatively small, rare, and deep water species, not much is known about its behavior.
The Greater Sand Perch can be easily confused with the Orange Spotted Sand Perch, Diplectrum eumelum (orange spots on checks, wide spur), the Bighead Sand Perch, Diplectrum euryplectrum (dark stripe along the base of the rayous portion of dorsal fin), or the Highfin Sand Perch, Diplectrum labrum (four double dark bars on sides).
The Greater Sand Perch is found in all Mexican fishing waters with the exception that it is absent from the Sea of Cortez and from around Mexico's oceanic islands. It is considered to be an excellent food fish and is sold commercially.
It is a member of the Serranidae Family which includes perches, groupers and sea basses.