Pacific Sand Perch, Diplectrum pacificum
The Pacific Sand Perch, Diplectrum pacificum, whose common Spanish name is Serrano Cabaicucho is a member of the Sea Bass or Serranidae Family, known collectively as “serranos” in Mexico.
The Pacific Sand Perch has a long slender body with an overall tan coloration, white belly, and a head covered with orange spots. The head has a narrow bony cheek spur (preoperculum) with five to eight long spines (as pictured below), whose shape is a key to identification. They have a series of nine dark bars along the lower half of the body. The caudal fin has five rows of spots, the top border is red and the lower boarder is white. The dorsal fins have two rows of spots. Adults have a large pink blotch on the abdomen above and just in front of the anus, a large purple spot on the gill covers, and a black spot at the base of the tail. They have yellow anal and pelvic fins.
The Pacific Sand Perch are found over sandy bottoms at depths up to 400 feet. They reach a maximum length of 28.5 cm (11.2 inches), documented by a fish that we caught. In Mexican waters the Pacific Sand Perch is found from Magdalena Bay south along the Pacific side of Baja, throughout the Sea of Cortez, and along the coastal mainland south to Guatemala. They are a small, rare, deep water species and not much is known about their behavioral patterns.
The Pacific Sand Perch is difficult to correctly identify because there are eight very similar Sand Perches, all of the Diplectrum Genus, that live in Mexican waters of the Pacific. The key to a correct identification is the unique shape of the peroperculum. In addition to the Pacific Sand Perch we present five additional Sand Perches: the Bighead Sand Perch, Diplectrum euryplectrum; the Bridled Sand Perch, Diplectrum rostrum; the Greater Sand Perch, Diplectrum maximum; the Highfin Sand Perch, Diplectrum labarum; and the Mexican Sand Perch, Diplectrum macroproma. There are two additional Sand Perches found in Mexican waters of the Pacific that we are seeking: the Orange-Spotted Sand Perch, Diplectrum eumelum (maximum length 31 cm – 12.2 inches, preoperculum wide with eight to fourteen long spines, face large covered with orange spots and stripes, caudal fin with bars of orange spots); and the Squirrel Sand Perch, Diplectrum sciurus (maximum length 17 cm – 6.7 inches, preoperculum square with five to ten large spines, body with two dark stripes and eight to ten dark bars, dorsal fin with two to three rows of yellow spots).
The Pacific Sand Perch is too small and too rare to be of interest to most.