Spotted Sleeper, Eleotris picta
The Spotted Sleeper, Eleotris picta, whose common Spanish name is guavina manchada, is a member of the Sleeper or Eleotridae Family, known collectively as guavinas in Mexico. Globally, there are 33 species in the genus Eleotris, three of which are found in Mexican waters, two in the Atlantic and one in the Pacific.
The Spotted Sleepers have stout elongated bodies that are deepest before the first dorsal fin and have a depth that is 22% to 26% of standard length. They are dark brown to blue-gray with a lighter colored belly and numerous white spots covering their body. Their fins are dark with transparent spots producing alternating bands of clear and dark. Their anal fin has one spine and seven or eight rays; their caudal fin is round with a long base; their first dorsal fin has a short base and five or six spines; their second dorsal fin has one spine and seven or eight rays and is shorter than the distance separating it from the caudal fin; and their pelvic fins are long and completely separated and have one spine and five rays. Their head is broad and depressed with a short snout, small eyes, and a large oblique mouth that has a strongly projecting lower lip equipped with several rows of small conical teeth on both jaws. Their gill openings are well back ending just before the first dorsal fin origin. They have a strong forward pointing spine embedded in the lower rear corner of their gill cover. They do not have a lateral line and are covered with small scales that are rough at the rear of their body.
The Spotted Sleepers are found in fresh and brackish waters at depths up to 15 feet. They reach a maximum length of 54 cm (21 inches) as established by a fish in my possession, which extended the known length for this species by a full 18.5 cm (7.3 inches). They take refuge during the day in rocks and bushes and emerge at night as carnivorous ambush predators feeding on crustaceans and fish. They are found at elevations up to 300 feet preferring low volume stagnant freshwater with year-round temperatures between 25oC (77oF) and 33oC (91oF). They feed on small shrimp and fish. Reproduction includes pelagic eggs and larvae. They are poorly studied and very little is known about their behavioral patterns.
In Mexican waters the Spotted Sleepers are found in all rivers and freshwater systems that feed the Pacific Ocean around the tip of the Baja, in the lower half of the Sea of Cortez, and along the coast of the mainland south to Guatemala.
The Spotted Sleepers are an important food fish in several countries of South America where they are cultivated and exported to the United States. Although fairly common in Mexican freshwater of the Pacific watershed, they are of limited interest to most with the exception of subsistence fishermen. From a conservation perspective they are considered of Least Concern, being widespread and common with stable populations.
Spotted Sleeper, Eleotris picta. Fish collected by locals with a cast net at the mouth of the San José River, Baja California Sur, August 2008, during a breach in the barrier. Length: 54 cm (21 inches). Identification courtesy of H.J. Walker, Jr. and confirmed by Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.
Spotted Sleeper, Eleotris picta. Fish collected by locals with a cast net at the mouth of the San José River, Baja California Sur, January 2011, during a breach in the barrier. Length: 18.0 cm (7.1 inches). Identification courtesy of H.J. Walker, Jr. and confirmed by Dr. Phil Hastings, Scripps Institution of Oceanography, La Jolla, CA.