OTHERS
MORMYRIDAE FAMILY
The Mormyridae or Elephant-nose family consists of 18 genera and 200 species. Mormyrids are distinguished by their snout which often is extended into a proboscis. The caudal peduncle serves as the site for a weak electrical organ used in orientation. Using this organ, Mormyrids are able to communicate with each other, find prey, and detect predators is murky waters or at night. Mormyrids have a large brain-nearly equal in the body weight to brain weight ratio of humans. Most Mormyrids are nocturnal or crepuscular species.
Long-nosed Elephant Fish, Elephant Nose, Peter's Elephantnose [
Gnathonemus petersii
SYN : Mormyruspetersii, Gnathonemus pictus
PD : This species has an elongated, laterally compressed body. The Elephant Nose has a small round mouth that is located above its trunk-like extension or proboscis. The dorsal and ventral profiles are symmetric with the anal and dorsal fins being located across from one another. The caudal fin is forked. The coloration is black or blackish-brown with two yellowish-white stripes extending vertically between the dorsal and anal fins.
SIZE : To 9" (23 cm)
SS : Other Gnathonemus species.
HAB : Moving water, often muddy, near submerged wood in West and Central Africa; Zaire,Nigeria, Cameroon .
S : bottom, middle
TANK : A 30" (76 cm) or 25-30 gallon (95-114 L) is sufficient, although larger tanks are required for individuals exceeding 6" (15 cm) in length. The tank should be well-planted and muted lighting should be used. Provide overturned flower pots, pipes, caves, or tubes for each fish to serve as a retreat. Use fine gravel or sand as a substrate. Furnish the tank with wood and rocks.
WATER : pH 6-7.2 (6.7), 3-12 dH (7), 73-82�F (23-28�C)
SB :The Elephant Nose is peaceful with other community fish, but territorial with others of its own species. Do not combine with aggressive species (Cichlids) for the Elephant Nose may not be able to compete for food. Do not keep in pairs as the weaker fish may be harassed. The Elephant Nose can be combined in groups of three or more because the aggression is dispersed. A nocturnal species.
SC : Congo Tetra, Synodontis , Characins, Killifish, Eartheaters, Angelfish, African Butterfly fish, West African Cichlids
FOOD : Live; Tubifex , other worms, insect larvae , Artemia; occasionally flakes. Feed after the lights are off.
SEX : No obvious external differences, the electric organ discharge (EOD) in G. petersii is used in sexual identification.
B : According to Dr Robert Landsman of ANOVA Science Education , one reason that this species has not been bred in captivity is that the electric signals of males and females sex reverse so that males send out female-like (shorter shaped) signals and females send out male-like (longer shaped) signals when they are brought into captivity. Thus, captivity induces signal sex-reversal so that the fish probably cannot communicate between genders appropriately. Learn more >
BP : 10. This species has not been bred in captivity.
REMARK S :The Long-nosed elephant fish has an electrical organ which it uses to find its food. It's brain size to body weight ratio is higher than that of humans. Unlike man, it's cerebellum is larger than it's front brain. The Long-nosed elephant fish is used by water departments in the U. S. and Germany to test the quality of drinking water. When the quality of the water declines the amount of electrical pulses released increases. Since the Long-nosed elephant fish has very poor vision, it uses the trunk or proboscis to locate it's food. Elephant-nose fish are depicted in ancient Egyptian tombs dating from around 2500 BC. Always use a good water conditioner for this sensitive species. They are often intolerant of fish medications.
DC : 5. This interesting species requires live foods and well maintained water.
Worm-jawed Mormyrids; Blunt-Jaw Elephantnose [
Gnathonemus tamandua
SYN : Campylomormyrus tamandua, Gnathonemus elephas, Mormyrus tamandua
PD : An elongated, laterally compressed species. The Blunt-Jaw Elephantnose's mouth is located near the end of its large proboscis. The lower part of the proboscis protrudes past the mouth. The dorsal and ventral profiles are symmetric with the anal and dorsal fins being located across from one another. The caudal fin is forked. The coloration is brown-gray with several brownish-white markings.
SIZE : To 16" (40 cm)
SS : Other Gnathonemus and Campylomormyrus species.
HAB : In murky water with submerged wood in Western Africa ; Niger and Zaire.
S : bottom
TANK : A tank measuring 48" (122 cm) with a capacity from 55 gallons (209 L) is sufficient for fish to 10" (25 cm) in length. Larger fish require larger tanks. Use dim lighting and provide hiding places with pipes, tubes, caves, and wood. The tank should be well-planted with large, robust plants and have a cover of floating plants. Use a filter that provides a strong current. Use a fine gravel or sand substrate, for this fish burrows. The Worm-jawed Mormyrid prefers large, shallow tank having peat filtration.
WATER : pH 6.0-7.5 (6.8); 5-20 dH (6); 73-82�F (23-28�C)
SB : A species that is territorial and aggressive towards similar species although peaceful towards different large species. Do not combine with small species.
SC : Haplochromis, Synodontis, Cichlasoma, Tilapia, Pimelodids, Doradids, Loricarids, African characins.
FOOD : Live; Tubifex , small fish, worms, insect larvae
SEX : The rear edge of the anal fin of males is curved, while the edge of females is straight.
B : Unknown
BP : 10. This species has not been bred in captivity.
REMARK S : This species requires frequent partial water changes.
DC : 7. The Worm-jawed Mormyrid is a fairly difficult species to care for. It requires live foods and is aggressive. It is sensitive to medications and unfavorable water conditions.
Large-scaled Mormyrid, Bulldog [
Marcusenius macrolepidotus
SYN : Gnathonemus macrolepidotus, Mormyrus macrolepidotus
PD : An elongated, laterally compressed species with a long, slender caudal peduncle and a forked caudal fin. The anal and dorsal fins are located opposite one another and are situated far back on the body. The forehead is large and rounded and there is lobe on the lower jaw. The color is light brown to dark gray with a silver iridescence. The body may be spotted with irregular brown spots.
SIZE : To 12" (30 cm) in nature, although rarely larger than 8" (20 cm) in captivity.
SS : Marcusenius species, and Hippopotamyrus species.
HAB : Southern Africa; widespread in the Cunene, Okavango, upper Zaire, and Zambezi river systems.
S : bottom, middle
TANK : A 40" (101 cm) or 45-55 gallon (170-209 L) tank is sufficient. Follow suggestions for G. petersii.
WATER : pH 6-8 (7.5), 5-18 dH (10), 68-79�F (20-26�C)
SB : A territorial species that is aggressive towards similar fish. It is possible to maintain this species; species is a school of six or more in a large tank. A nocturnal species.
SC : Gouramis, Barbs, Synodontis, West African Cichlids, African characins
FOOD : Live; Tubifex , other worms, insect larvae , Artemia; occasionally flakes. Feed after the lights are off.
SEX : Skelton (98) reports that males have a notch in their anal fin, while females do not.
B : Has not been accomplished in aquaria, although has been observed in nature. According to Skeleton (98), this species spawns during the rainy season is shallow, planted areas. As many as 6000 eggs are laid.
BP : 10. Breeding has not been accomplished in aquaria, although may be possible by recreating the rainy season in a large tank.
REMARK S : Mass migrations in nature have been reported, although these have not been linked to the spawning season.
DC : 6. This large species requires live foods and a well-maintained tank.
Baby Whale [
Pollimyrus isidori
SYN : Mormyrusisidori
PD : A bullet-shaped species with strong lateral compression and a long, slender caudal peduncle. The head and snout are rounded and the mouth is small. The anal and dorsal fins are located far back on the body and are opposite one another. The body color is light gray to gray-brown and can be speckled with small dark spots. The fins are brown and the caudal fin is forked. A faint red stripe extends from the caudal peduncle to the gill cover.
SIZE : To 6" (15 cm) in nature, although rarely larger than 3.5" (9 cm) in captivity.
SS : Marcusenius species, Hippopotamyrus species, Petrocephalus species, and other Pollimyrus species.
HAB : Africa; Lower Nile, Upper Zambezi
S : bottom, middle
TANK : A 28" (71 cm) or 20-25 gallon (76-95 L) tank is sufficient. Follow suggestions for G. petersii.
WATER : pH 6-8 (7.5), 4-18 dH (10), 77-84�F (25-29�C)
SB : A peaceful, schooling fish recommended for a community tank. This species should be kept singly orin groups of five or more. It is important to provide a retreat for each fish. Larger Mormyrids tends to harass this gentle, but territorial species. A nocturnal species.
SC : See M.macrolepidotus.
FOOD : Live; Tubifex , other worms, insect larvae , Artemia; occasionally flakes. Feed after the lights are off.
SEX : Unknown
B : Unknown
BP : 10. Breeding has not been successful.
REMARK S : An easy fish to keep, although it is sometimes intolerant of unfavorable water conditions.
DC : 5. This interesting species requires a diet of live foods.