Greater Sand Perch, Diplectrum maximum

Greater Sand Perch, Diplectrum maximum, Juvenile. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, May 2011. Length: 20 cm (7.9 inches). Note the black spot between the first and second dorsal spines.

Greater Sand Perch, Diplectrum maximum, Juvenile. Fish caught from coastal waters off Puerto Adolfo Lopez Mateos, Baja California Sur, July 2016. Length: 16 cm (6.3 inches).

Greater Sand Perch, Diplectrum maximum. Fish caught from coastal waters off Point Palmilla, Baja California Sur, December 2010. Length: 36 cm (14 inches).

Greater Sand Perch, Diplectrum maximum: preoperculum.

Greater Sand Perch, Diplectrum maximum, Pugheaded. Fish provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, January 2010. Length: 36 cm (14.2 inches). A fish with a rare condition known as “pugheaded.”

The Greater Sand Perch, Diplectrum maximum, is a member of the Sea Bass or Serranidae Family, and is known as serrano de altura. Globally, there are twelve species in the genus Diplectrum, of which ten are found in Mexican waters, two in the Atlantic and eight in the Pacific Ocean.

The Greater Sand Perch has an elongated body with an overall tan coloration and a white belly. Their head is dark gray-brown in its upper two-thirds and features a narrowly pointed and rounded bony cheek spur (preoperculum) with 4 to 8 large spines (pictured above) that is a key to their identification. Their lower jaw is strongly projecting. They have a dark blue-gray blotch on the upper edge of their gill cover. Juveniles have a black spot in the membrane between their first and second dorsal spines. Their anal fin is gray, their caudal fin is gray-brown, their dorsal fin features blue-gray and red-brown bands with red-brown margins, their pectoral fins are translucent yellowish-brown, and their pelvic fins are dark gray. Their anal fin has 3 spines and 7 rays; their caudal fin is concave; their dorsal fin has 10 spines, the second and third dorsal are of equal length, and 12 rays.  They have 17 to 21 gill rakers. They are covered with small rough scales.

The Greater Sand Perch is found over sandy bottoms at depths between 60 m (200 feet) and 121 m (400 feet). They are the largest of the nine Sand Perches found in Mexican waters of the Pacific and reach a maximum of 45 cm (17.7 inches) in length and 1.5 kg (3 lbs 5 oz) in weight, as documented by a fish that I caught. As of January 1, 2024, the International Game Fish Association world record stood at 0.5 kg (1 lb 2 oz) with the fish caught from coastal waters off Point Palmilla, Baja California Sur, March 2022, by my good friend Luke Ovgard. The Greater Sand Perch are synchronously hermaphroditic possessing both males and female organs and capable of producing eggs and sperm at the same time. They spawn in deep water as mating pairs. Their eggs and larvae are pelagic and move to shallower waters as they mature. The Greater Sand Perch is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Greater Sand Perch is a resident of all Mexican waters of the Pacific with the exception that they and were thought to be absent from the Sea of Cortez, however, they are actually very abundant along the southeast coast of Baja as documented by numerous fish that I have caught.

The Greater Sand Perch is the easiest to identify of the eight very similar Sand Perches, all of the Diplectrum Genus, living in Mexican waters of the Pacific Ocean. The key to a correct identification is the unique shape of the preoperclum. See Sand Perch Preoperculum for an interesting side-by-side look at some fish anatomy of seven very similar looking fishes of the Diplectrum Genus found in the Pacific Ocean.

From a conservation perspective the Greater Sand Perch is currently considered to be of Least Concern with stable widely distributed populations. They are fairly abundant in the greater Los Cabos area. The Greater Sand Perch is one of the very best bottom fish for human consumption that is caught in Mexican waters. They are sold extensively in local fish markets. Their roe is considered to be a delicacy. They are the only Sand Perch that I are aware of that when hauled up from the deep will return to the deep on their own. They consume a variety of small fishes, which are frequently regurgitated and found on the panga floor or in the fish box.