Squirrel Sand Perch, Diplectrum sciurus

Squirrel Sand Perch, Diplectrum sciurus. Fish caught from coastal waters of Bahía de los Ángeles, Baja California, April 2025. Length: 17 cm (6.7 inches). Catch, photographs and identification courtesy of Chris Wheaton, Fullerton, California. Productive discussions with Dr. Ross Robertson, Smithsonian Institute, Panama City, Panama noted.

The Squirrel Sand Perch, Diplectrum sciurus, is a member of the Sea Bass or Serranidae Family, that is also know as the Gulf Sand Perch and the Gulf Squirrelfish and in Mexico as camotillo ardilla. Globally, there are twelve species in the genus Diplectrum, of which eleven are found in Mexican waters, two in the Atlantic and nine in the Pacific Ocean.

The Squirrel Sand Perch has an elongated body that is slightly compressed with an overall gray-brown coloration. Their body has two dark stripes and eight to ten bars. The caudal fin is dark with irregular yellow spots. Their spiny dorsal fin has two rows of yellow spots that extend into the soft dorsal with two rows. They have a black blotch at the caudal base. Their bony cheek spur (preoperculum) is square with 5 to 10 large spines which is a key to their identification. Their anal fin has 3 spines and 7 or 8 rays; their caudal fin is concave; their dorsal fin has 10 spines and 11 to 13; and, their pelvic fins are inserted under the pectoral fins. They have 32 to 41 gill rakers. They are covered with small rough scales.

The Squirrel Sand Perch is found over sandy bottoms at depths between 25 m (82 feet) and 10 m (330 feet). They are the smallest of the nine Sand Perches found in Mexican waters of the Pacific and reach a maximum of 17 cm (6.7 inches) in length. The Squirrel Sand Perch are synchronously hermaphroditic possessing both males and female organs and capable of producing eggs and sperm at the same time. The Squirrel 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 Squirrel Sand Perch is ENDEMIC to Mexican waters of the Pacific Ocean with a limited range being found along the southwest coast of the Baja Peninsula and throughout the Sea of Cortez.

The Squirrel Sand Perch is exceeding rare and seldom seen by humans. The eight Sand Perches from Mexican waters of the Pacific Ocean are very similar and difficult to identify. The Squirrel Sand Perch has more gill rakers, 32 to 34, than any of the other Sand Perches and its dorsal fin is the only one with two rows of orange spots. In addition a correct identification can be aided by the uniquely shape of the preoperculum of the Squirrel Sand Perch. See Sand Perch Preoperculum for an interesting side-by-side look at some fish anatomy of eight very similar looking fishes of the Diplectrum Genus found in the Pacific Ocean.

From a conservation perspective the Squirrel Sand Perch has not been formally evaluated and thus their status is unknown. They are small in stature, seldom seen by humans and of limited interest to most.