Eartheaters are widespread throughout South America. Five genera make up this group:
Biotodoma
,from the Amazon and Orinoco watersheds and the coastal rivers of the Guyanas;
Geophagus
, widespread throughout four majorrivers basins;
Gymnogeophagus
of the Rio Parana watershed;
Retroculus
, from the rapid rivers of FrenchGuyanas and the lower Amazon; and
Satanoperca
of the Amazon and Orinoco watersheds, and Guyana.
SIZE
: Eartheaters usually range in size from 6-12" (15-30 cm), although some speciesgrow no larger than 4" (10 cm).
TANK
: Because of the wide range of size between Eartheaters, it is difficult to suggest a propertank size. It is safe to say that for the larger species, the tank should measure at least 48" (122 cm) witha capacity of 55 gallons (209 L). Furnish the tank with a fine gravel or sand substrate as Eartheaters will sift throughthe bottom material. Use caves, roots, and wood for hiding places. Live plants can be used, although theyshould be potted and robust. Leave open swimming areas and open patches of sand. Flat stones can serve as potential spawningsites.
WATER
: Many species can accept a wide range of water conditions. For practical purposes, only the generalperimeters will be given: a pH from 6.5-7.5, a water hardness from 5-15 dH, and a temperature from 72-79°F(22-26°C).
SB
: Eartheaters come in a wide range of dispositions. Most are territorial, but many are peaceful,while others are aggressive and intolerant. See individual descriptions.
SC
: Eartheaters can be combined with a wide range of other species, depending on the speciesof Eartheater. Suitable tank mates for smaller eartheaters include catfish (Loricarids,
Corydoras
,and Doradids), characins (tetras, over 2.4," of the upper swimming levels; hatchetfish; pencilfish), cichlids (Angelfish,Severum, Festivum), and fish from other regions (Gouramis, Danios, Rasboras). Larger Eartheaters can be combined withlarger catfish (Pimelodids, Loricarids, Doradids), larger characins (Silver Dollars), and cichlids (Cichlasomines). Bearin mind that Eartheaters practice brood care and are inhospitable towards other tank mates around spawning times. ThusEartheaters are best spawned in a tank of their own.
FOOD
: In nature, Eartheaters receive a fair part of their diet by sifting through the substrate. Inaquaria, they can be fed on such live foods as: worms, aquatic insects, insect larvae, and crustaceans. Mostwill also accept flakes, tablets, and pellets.
B
: Three major types of reproduction have been observed: substrate spawning, delayed (primitive)mouth brooding, and immediate (advanced) mouth brooding.
(1) Substrate spawners (
Geophagus brasiliensis
) lay their eggs on a flatstone or piece of wood that is located out in the open. The parents guard the eggs and the fry there.
(2)
Satanoperca leucostictus
is an example of a delayed mouthbrooded, which lays its eggs on a flat surface and guardedby the female until the fry hatch. The fry are taken into the female's mouth where they are incubatedfor a period of two weeks. In this method the pair breaks up following the spawning.
(3)
Geophagus steindachneri
is an immediate mouthbrooded. After the eggs are fertilized, they are taken into the mouth of thefemale where they are incubated until the young can fend for themselves. In this reproductive method, the malesform harems and are strongly polygenic.
BP
: Eartheaters spawn in several different methodswith a different degree of difficulty, thus one should see the individual descriptions for the rating on a particularspecies.
R
: Eartheaters earned their common name by their habit of taking mouthfuls of substrateinto their large, under-slung mouths. They do this in order to obtain food. The substrate is filter through a partof the gill known as "rakers" where food is separated from debris. The waste is passed through the gillsand back into the water, leaving only the edible substance in the fish's mouth.
DIFFICULT OF CARE: See individual descriptions as to the degree of difficulty in care.
Cupid Cichlid
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Biotodoma cupido
SYN
:
Acarasubocularis, Geophagus cupido
PD
: A cichlid with a rounded forehead and an elongated caudal penuncle. The dorsal and pelvic fins are elongated,and the caudal fin is fan-shaped. Different color varieties exist. A common variation has a gray back . Theflanks are marked with fine transverse stripes that may or may not be visible. A black spot is located on the rear,upper-part of the fish. A black band runs through the eye from the forehead to the corner of the gill cover. Thecoloration changes (depending on the angle of light) from orange to yellow to green to blue and finally, to purpleas it nears the caudal fin. This rainbow of colors develop only in mature specimen that are kept in exceptionally maintainedwater. Young fish are dull gray. The dorsal fin is pinkish-red, while the anal fins is a dark violet.The tail may be grayish-green. The pelvic fin is turquoise in color.
SIZE
: To 5.5" (14 cm), although usually smaller
SS
:
Biotodomawavrini
HAB
: Found is slow-moving, wide parts of clear rivers. South America; Rio Tapajo near Santarèm(Brazil).
S: bottom, middle
TANK
: A tank measuring 32" (81 cm) with a capacity of 30 gallons (114 L) is sufficient. Theforeground should include a fine gravel or sand substrate, and be open. The background should include hidingplaces among thickets of hardy plants, roots, caves, and wood.
WATER
: pH 5-7 (6.5), dH 0-6 dH (2), 77-84°F (25-29°C).
SB
: A territorial and somewhat aggressive fish that should be kept in pairs. Problemswith pairing are common, so allow a group of youngsters to pair off, and select the best pair. This species should be kept with calm,small to medium-sized fish of the upper swimming levels. Pairs form a nuclear family.
SC
: Tetras, Headstanders, larger hatchetfish, Loricarids,
Pimelodus
, Armored catfish, dwarf Acaras
FOOD
: Live; insect larvae, crustaceans,
Tubifex
; flakes, pellets.
SEX: Males have blue iridescent lines on their cheeks, while females have spots.
B
: Use water with a pH from 6.0-6.5, a water hardness of 0-4 dH, and a temperature from81-84 F (27-29 C). The female will dig a pit with its mouth in the substrate. The female lays about 100 eggs whichare guarded by the male, with the female caring for the eggs. When the are free-swimming about 10 days later,they can be fed roftiers and liquid foods. After another week or two, they are large enough to be given brineshrimp nauplii. The parents continue their care for the young. The fry are difficult to raise.
BP
: 8. Breeding is difficult.
R
: Fish of the genus
Biotodoma
can be distinguished from other
Geophagus
,by their smaller snouts and mouth. The Cupid Cichlid is sensitive to changes in water conditions and pollutants. Wild-caughtspecimen are much more colorful, although they are also far more delicate.
DC
: 6. A delicate species that may, at times be aggressive towards others of its own species.
Pearl Cichlid, Mother-of-Pearl Eartheater
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"Geophagus" brasiliensis
SYN
:
Acarabrasiliensis, Chromis brasiliensis, Geophagus labiatus, G. obscura, G. pygmaeus
PD
: A laterally compressed cichlid with a rounded forehead. The anal, dorsal, and caudal fins arelarge when compared to those of other Eartheaters. The back is dark and the belly is salmon-pink. The body color ranges from yellow tobrown to dark red, and each scale is marked with a blue, green, or yellow spot. The fins retain the scale pattern andcoloring, except to have more blue and violet hues. The iris of the eye is golden with a black band running through it. A lateralstripe, sometimes unnoticeable, runs from the eye to the base of the caudal fin. Fish under 3" (8 cm) are an unattractivebrown color.
SIZE
: Males to 12" (30 cm) in nature, although no larger than 9" (23 cm) in captivity. Femalesreach 6" (15 cm) in captivity.
SS
: "
Geophagus"gymnogenys
HAB
: South America; found in the coastal rivers of Brazil. This Eartheater is found along rockybanks of rivers that receive tidal influence.
S: bottom
TANK
: A tank measuring 48" (122 cm) with a capacity of 55 gallons (209 L) is needed foradult sized fish. Use a substrate of fine gravel or sea sand-for buffering the pH. The tank should be arranged with rockstructures including caves. Only robust, potted plants should be used.
WATER
: pH 6.7-8.2 (7.3), 5-20 dH (11). This species can tolerate a temperature as lowas 50°F (10°C) for short periods of time, although it can be kept in a cool tropical set-up with temperaturesfrom 66-75°F (18-24°C).
SB
: A territorial, but peaceful species that is tolerant of other fish, including Eartheaters. Combinewith medium to large sized fishes. Pairs form monogamous bonds and nuclear families.
SC
: Catfish (
Arius,Callichthys,
Loricarids, Pimelodids, Doradids), characins (SilverDollars, Headstanders), cichlids (Eartheaters, Cichlasomines).
FOOD
: Live;
Tubifex
, crustaceans, snails, crabs; chopped meat; mussels; pellets; tablets.
SEX: Males develop nuchal humps on their forehead with age. The male reaches a larger size and hasa more elongated dorsal fin. The genital papilla of the male is pointed.
B
: Use water with a pH from 6.5-7.2, a water hardness from 5-10 dH, and a temperature from75-79°F (24-26°C). Condition the pair with nutritious live foods. As many as 800 eggs are deposited ona previously cleaned surface that is usually hidden. The parents are fine parents which carefully care for the fry. Startfeeding with crushed dry foods and
Artemia
nauplii. The young grow quickly when fed often and kept in well-maintained water. The eggs may be consumed in cases wherea compatible pair is not found.
BP
: 6. Breeding is fairly easy.
R
: A 0.5% addition of salt can be used. This can be accomplished by adding 4 TSP. ofsalt per every 10 gallons (5 g of salt/10 L).
DC
: 4. A hardy fish recommended for the aquariast wanting to begin collecting Eartheaters.
Red hump Eartheater
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"Geophagus" steindachneri
SYN
:
Geophagushondae, G. magdalenae, G. pellegrini
PD
: Males have a large, characteristic hump on their forehead that develops with age. Thebody coloring differs depending on the population. Common colors are gold, green, red, orange, and black. Thebody is marked with irregular black spots. The hump may change from golden to red. The fins are spotted with iridescentscales. The male has an orange spot at each corner of his mouth. These serve as the equivalent of theegg-spots of Lake Malawi Cichlids.
SIZE
: To 10" in nature, although tank-bred fish usually do not exceed 6" (15cm). Femalesare considerably smaller.
SS
: "
Geophagus"surinamensis
HAB
: South America; upper parts of the Rio Magdalena and its tributaries in Columbia andVenezuela.
S: bottom
TANK
: A tank measuring 48" (122 cm) with a capacity of 50 gallons (190 L) is recommendedfor adult fish. Use a deep substrate of sand or fine gravel. The back parts of the tank should beplanted with large, well-rooted plants. Use wood, rocks, and caves for hiding places.
WATER
: pH 6.5-7.2 (7.1), 5-15 dH (8), 75-81°F (24-27°C)
SB
: Females are not territorial, while dominant males can be aggressive. This species can be combined with medium-sizedfish of the upper swimming levels, and other Eartheaters. Pairs may become aggressive during spawning season. Keepone male with several females. Females perform matriarchal duties, while males often form harems.
SC
: Catfish (Loricarids, Pimelodids, Doradids), characins (Silver Dollars, Headstanders),cichlids (Eartheaters, Cichlasomines).
FOOD
: Live; crustaceans,
Tubifex
, insects larvae; pellets; tablets; choppedmeat.
SEX: Males are larger and more colorful with an egg spot at each corner of the mouth. Malesalso have a characteristic hump on their forehead.
B
: Use the recommended water values and a temperature between 77-82°F (25-28°C). Dependingon the size of the female, from 30-150 bright yellow eggs are laid on a previously cleaned stone, following a briefcourtship. The eggs are immediately taken into the female's mouth along with the sperm of a male. Theeggs are mouthbrooded for a period of 15-20 days. The female should not be fed during this time as she may accidentallyswallow her brood. The large fry are easy to feed with dry and small live foods.
BP
: 6. Breeding is not difficult.
R
: Several different coloration/geographical populations are known to exist. Sexuallymature from 2.8" (7 cm).
DC
: 4. A robust and peaceful Eartheater.
Paraguay Mouthbrooder, Paraguay Eartheater, Balzanii
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Gymnogeophagus balzanii
SYN
:
Geophagusbalzanii
PD
: An oval shaped fish with a tiny mouth. Males develop an enormous hump on theirforehead that extends from the front of the base of the dorsal fin, to the lips. The body coloring is generally lightgray to brown on the upper flanks. The belly and the lower flanks are golden-yellow to chestnut brown. Occasionallya few orange spots may be scattered on the hump, near the eye. The fins are yellow to gold in color with somewhite spots on the edge of the anal, dorsal, and pelvic fins. Females develop a dark spot and a stripe runningfrom the eye to the cheek in their spawning dress. Some fish may have five to eight, vertical stripes on the body.
SIZE
: Males to 8" (20 cm), females to 5.5" (14 cm)
SS
: None
HAB
: Found in still and slow-moving swamps along rivers. South America; Rio Paraguay, Rio Parana(Paraguay and Argentina).
S: bottom
TANK
: A 48" (122 cm) tank with a volume of 55 gallons (209 L) is ideal for adult fish. Usea sand or fine gravel substrate. Only robust, potted plants should be used as this fish is a burrower. Leave some flat stones as this fishlikes to rest on them. Provide hiding places with roots and wood.
WATER
: pH 6.5-7.5 (7.0), 4-14 dH (8). Although in nature, the Paraguay mouthbroodedcan sometimes tolerate water temperatures as low as 59°F (15°C), it should be kept in water with a temperaturefrom 70-77°F (21-25°C).
SB
: A territorial, but peaceful and tolerant species that can be combined with other calmfish. Males form harems, so it is best to keep one with two or more females. This species will not harm plants otherthat burrowing.
SC
: Catfish (Loricarids, Pimelodids, Doradids, Armored Catfish), characins (Silver Dollars,Headstanders, larger tetras), cichlids (
Geophagus,Gymnogeophagus
, Severum, Festivum).
FOOD
: Live; snails, crustaceans, aquatic insects, insect larvae,
Tubifex
; tablets.
SEX: At two inches (5 cm) males begin to develop their large nuchal humps that cover theirentire forehead. Males are also larger and more colorful.
B
: Use neutral water with a hardness from 8-12 dH, and a water temperature from 75-81°F(24-27°C). The female deposits up to 500 eggs on previously cleaned rocks. The male fertilizes the eggs and thenleaves. After 24-32 hours the larvae are sucked into the female's mouth, with the eggs shells being leftbehind. After the fry are released they can be fed with liquid foods and roftiers. Later they can be raised on brine shrimpand
Cyclops
nauplii. The fry retreat into the mother's mouth at times of danger. The fry are slow-growing and difficultto raise.
BP
: 7. Breeding is moderately difficult although the fry are difficult to rear.
R
: Do not keep the Paraguay Mouthbrooder at too warm a temperature as it causes the fish tobecome more sensitive. The water must be well-maintained with frequent partial water changes as this cichlid isvery sensitive to the build-up of toxic compounds. When water qualities decline, the fish are susceptible to hole-in-the-headdisease. Sexual maturity is reached at the age of one year when fish measure about 2.3" (6 cm). Eightspecies belong to the genus
Gymnogeophagus
or "Naked Eartheater" group. Nearly all fish available to the hobby are captivebred.
DC
: 6. A sensitive species who characteristic hump makes it quite interesting.
Demon Fish, 'Jurupari,' Eartheater
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Satanoperca leucosticta
SYN
:
Geophagusjurupari, G. leucostictus, Satanoperca jurupari, S. leucostictus
PD
: An elongated, laterally compressed cichlid with a large, rounded head. Eachray of the dorsal fins comes to a shape point. The body color is greenish-yellow to yellow-brown with each scale havingan iridescent yellow to gold spot. On the head, these spots may develop a turquoise blue iridescence. Thefins retain a similar pattern as the body. Sometimes faint, broad transverse stripes are present on the body.
SIZE
: To 12" (30 cm), although not usually larger than 9" (23 cm) in aquaria
SS
: Other
Satanoperca
species
HAB
: South America; Brazil and Guyana.
S: bottom, middle
TANK
: A tank measuring 48" (122 cm) with a capacity of 55 gallons (209 L) is sufficientfor adult fish. Use a fine gravel or sand bottom. The tank should include hardy plants, roots,wood, and rocks for hiding places. Use an efficient filtration system as the substrate is stirred up fromconstant burrowing. This species favors peat filtration.
WATER
: pH 6.2-7.5 (6.9), 3-15 dH (8), 77-84°F (25-29°C)
SB
: A peaceful and non-aggressive cichlid. This Demon Fish is the most peacefulof the genus
Satanoperca
. Combine with other Eartheaters, catfish, and smaller fish of the upper swimming levels. Thiscichlid may not spawn with other species are present as the presence of other fish tends to intimidate them. Pairsform nuclear families.
SC
: Catfish (
Callichthys,
Loricarids, Pimelodids, Doradids), characins (Hatchetfish, Headstanders,large tetras), cichlids (Eartheaters).
FOOD
: Live;
Tubifex
, crustaceans; tablets; sinking flake foods.
SEX: Males are slightly larger and more slender with maturity.
B
: Use a separate breeding tank with the following range of water values: pH 6.2-7.0, 5-10dH, 81-86°F (27-30°C). Up to 400 eggs are laid on a previously cleaned stone. These eggs are tended to and guardedfor a period of 24-30 hours, when they are taken into the mouth of the female. Over the course of two weeks, the mouthbrooding duties are evenly shared between the two parents. The fry are held in the front of the mouth, notin the throat sac like many other species. After two weeks, when the fry are free-swimming, they are released. Startfeeding with
Artemia
nauplii. The fry seek shelter in the parent's mouth at times of danger. Remove the fry after a period of threeto four weeks. The young grow slowly.
BP
: 7. Breeding is moderately difficult to induce, and the fry are not easy to raise.
R
: This species is often sold under the name
S. jurupari
, although
S. jurupari
is a separate, seldom imported,species. The name
Satanoperca
is Latin for 'Satan's Perch.' Jurupari is taken from the Tupi Indian word meaning 'demon's lure,'after a relationship drawn between this species and the forest demon mentioned in local folklore.
DC
: 5. A hardy and peaceful Eartheater that is sensitive to cool water.
Shark-repelling fishing gear in the works
(4/23/2008) Fishing gear that produces an electric field in sea water could help prevent sharks from becoming accidental bycatch, say scientists at NOAA.
Feds flood the Grand Canyon to save endangered fish
(3/5/2008) Federal government officials unleashed a flood of water from Glen Canyon Dam in northern Arizona to help restore the Grand Canyon's ecosystem which has suffered as a result of changes caused by the dam.
The copy for fish.mongabay.com was written in 1994-1995. Therefore some information such as scientific names may be out of date. For this, I apologize. Feel free to send corrections to me.
