The name Geophagus parnaibae is based on this eartheater’s area of distribution—the basin of the Rio Parnaíba. This species belongs to the Geophagus urinamensis complex and was previously known in the aquarium trade under the names Geophagus sp. “Parnaíba” and Geophagus sp. “São Benedito.” As befitting a fish of the Geophagus genus, G. parnaibae possesses a dark spot (in this case, medium size) on the lateral line, while its caudal fin exhibits a pattern in the form of very distinct parallel longitudinal stripes. However, this species lacks the black spot on the preoperculum, as well as a complete infraorbital stripe. It is a small cichlid that will grow to a maximum length of 16 cm ( 6 inches), though some people report only half that length. Although its temperament is quite peaceful, intraspecific aggression may occur among the dominant males, and at other times, females may be excessively pursued.
The Biotope
Geophagus parnaibae has a restricted distribution; it is likely to be
endemic to the drainage of the Rio Parnaíba in northeastern Brazil.
During the rainy season, this eartheater lives over the sandy bottoms
of streams and small rivulets in swift-flowing water, but in the
dry season it inhabits pools and ponds where the water
is still. The chemical and physical conditions in their
natural environment consist of a pH of 6. 5 to 7. 6, a GH
of 1 to 11, and a water temperature in the range of
24° to 31°C ( 75° to 88°F).
Feeding Habits
In their natural environment these
cichlids feed primarily on plants,
seeds, aquatic insect larvae, and
detritus. All kinds of crustaceans
(such as frozen daphnia and
krill) can serve as a substitute for
natural food in the home aquarium,
and blackworms and glassworms
are acceptable as well. While creating
the diet for these cichlids, we should never
forget fibrous substances, which constitute all
of the things that are not digested by the fish, like
chitin and cellulose. The former is contained in the shells of
animals such as Daphnia, Artemia, and Gammarus, while the latter is
a constituent of the cell walls of plants and can be found in vegetation
such as spinach. These substances in food regulate digestion and
prevent inflammation of the mucous membranes of the digestive
tract—their action can be likened to a plunger working to remove all
undigested food material from the intestines. These substances also
aid in the assimilation of proteins, carbohydrates, and fats.
Geophagus parnaibae, a beautifully colored adult.
Conditions in the Aquarium
A fundamental element in the decor of our aquarium is a thick
layer of fine sand, an area where the fish will be able to dig in search
of food. For decorative purposes, we can add pieces of driftwood or
petrified wood to the aquarium, which can double as hiding spots for
the cichlids. If the atmosphere becomes austere, it is advisable to add
plants, preferably some Echinodorus, Cryptocoryne, or Microsorum, the
latter of which looks best when it can wind its long roots around pieces
of driftwood and petrified wood.
Due to their small size (compared to other eartheaters), a group of
six adult individuals (this species is best kept in large groups) can
