Synonyms: Amblyopus brasiliensis, A. mexicanus, Gobioides oblongus, Ognichodes broussonnetii, Plecopodus broussonnetii
Physical description: A slender, elongated, eel-like species with a large head. The spiny dorsal fin runs nearly the length of the body, while the anal fin runs along the rear half of the body. The caudal fin is also long. The large scales are marked with brown markings. The back is brownish while the flanks are silver with a violet iridescence. The fins are brownish.
Size/Length: To 25" (64 cm) in nature, although smaller in captivity.
Similar species: None
Habitat: In coastal estuaries with fresh to brackish water having a muddy substrate. North America to South America; from Georgia south to Northwestern Brazil
Aquarium: A 48" (122 cm) or 55 gallon (209 L) tank is adequate. Use a fine gravel or preferably, sand substrate, because this fish likes to bury itself, and sharp rocks can injure the fish. Provide hiding places with rocks, wood, roots, caves, tubes, and tunnels. Leave large, open areas on the bottom for foraging.
Water chemistry: pH 7.2-8.5 (8.1), 12-30 dH (20), 68-75°F (20-24°C). A 1% addition of salt is recommended as these fish are found in brackish water. This can be accomplished by adding 7.5 TSP of salt/ 10 gallons (10 g/10 L).
Social behavior: A highly territorial, solitary fish that should be kept in a species tank. This fish is often territorial and aggressive towards others of its own species.
Suggested companions: Large livebearers, Scats, Monos, Arius, Rainbowfish.
FOOD: Live; fish, earthworms, Tubifex , aquatic insects, insect larvae; chopped meat. In nature this species feeds on small organisms in the substrate, by sifting mud in its mouth.
Sexual differences: No external differences are known, although males are more territorial at spawning times.
Breeding techniques: Spawning is possible in a large aquarium. Success in captive spawning is documented by Harper in Tropical Fish Hobbyist (#473), on pages 130-132. He suggests using a spawning group of one male and three or more females. The tank should be furnished with hiding places for the females and as a nest for the male. The fish should not be fed for a week and then conditioned on live foods. The salinity should be lowered 5 ppt and then raised 5-10 ppt to 30 ppt salinity. The male will spawn with several females over the course of a day. Following spawning, the females should be removed and the male will guard the eggs. After 36-48 hours, the fry hatch and the male should be removed. After the egg sacs are consumed, he fry can be fed roftiers and "green water" containing algae. After a month, Artemia nauplii can be fed.
Breeding potential: 10. No spawnings in captivity have been reported.
REMARKS: Handle this fish with care, they can inflict a painful bite.
Difficulty of care: 7. A highly aggressive fish that requires a diet of live foods, and is best kept in a species tank