Sleeper Family – Eleotridae

There are currently SIX members of the Sleeper or Eleotridae Family, three from the Atlantic Ocean and three from the Pacific Ocean,  presented in this website:

FROM THE ATLANTIC (3):

FROM THE PACIFIC (3):

The Sleepers or Eleotridae Family is a large family with one hundred sixty-four global members that have been placed into thirty-six genera with the majority being in the Genus Eleotris (thirty-one) and Mogurnda (twenty-six). Ten members of the family are found in Mexican waters, 6 in the Atlantic and 4 in the Pacific Ocean. They are small to medium-sized fish that reach a maximum length of 60 cm (2 feet 0 inches).  In Mexico they are known as guavinas. They are close relatives of the gobies (Gobiidae Family) but lack the fused pelvic fins that form the sucker in gobies. They have elongated, stout, and cylindrical bodies that are deepest before the second dorsal fin. Most are drab in color, however, during mating the males of some species exhibit vibrant breeding colorations. They have a short broad head with a blunt snout and a large oblique mouth that opens at the front and is equipped with small conical teeth set in several rows on the jaws. Their gill membranes are joined to the throat with 6 rays. Their anal fin originates behind the second dorsal fin and has 1 spine and 6 to 12 rays; their first dorsal fin has 6 or 7 weak spines and a short base; their second dorsal fin has 1 spine and 6 to 12 rays; their pelvic fins have 1 spine and 5 rays and have long bases that are either close together or united. They are covered with large scales that are smooth or rough. They have canals and pores on their head but do not have a lateral line. Most have relatively long lifespans in excess of ten years.

Members of the Sleeper Family are found primarily in fresh and brackish water systems among vegetation over sandy and muddy substrates. They are abundant in tidelands and within river mouths and generally found in waters that are less than 3 M (10 feet) in depth and below elevations 0f 30 m (100 feet). They prefer water temperatures between 25^oC (77^oF) and 33^oC (91^oF). A few spend their entire lives in the sea and a few migrate back and forth from brackish water to the ocean. Most can tolerate dramatic changes in the salinity of their habitat and some can survive out of water for extended periods of time. They are distinguished from each other by their teeth, gill rakers, and scales. They are benthic and lead lethargic lifestyles. They are strong ambush predators that consume detritus, plankton, and small fish playing an important role in freshwater stream ecosystems. Reproduction is oviparous with small adhesive eggs released by the females that are fertilized externally and then attach themselves to the substrate where they are maintained by both parents. They are scientifically interesting as they are believed to have evolved in the ocean and then moved to freshwater systems.

From a conservation perspective the majority of the Sleepers have not been formally evaluated but those that have are considered of Least Concern with stable, widely distributed populations. A few of the Sleepers are sold commercially and raised by aquaculture. Within some cultures they are an important food fish as they have a long shelf-live and can be maintained without refrigeration. A limited number of Sleepers are components of the aquarium trade.