Gymnogeophagus caaguazuensis
Gymnogeophagus caaguazuensis was officially described by Staeck in 2006. There is no commonly known English name for this fish.
Deze soort behoort tot de familie van de Cichliden (Cichlidae). Binnen de Cichlidae valt Gymnogeophagus caaguazuensis onder de stam Geophagini, die vaak worden aangeduid als “Aardeters” vanwege hun gedrag om substraat door hun kieuwen te filteren op zoek naar voedsel.
The genus name Gymnogeophagus is derived from the Greek words ‘gymnos’ (naked) and ‘geophagus’ (earth eater), referring to the bare skin and feeding habits of the fish in this genus. The species name caaguazuensis refers to the province of Caaguazú in Paraguay, where the species was originally discovered.
Description
Gymnogeophagus caaguazuensis is a small cichlid species that typically reaches a standard length of about 9 cm, with adult males growing up to 12 cm long. The total length, including the tail fin, is approximately 12 cm at most.
The species exhibits clear sexual dimorphism, with adult males being larger than females. Males have a more lyre-shaped tail fin. A lyre-shaped tail (often referred to as a lyretail) is a caudal fin with a characteristic fork shape. The upper and lower fin rays are elongated relative to the center of the tail. This gives the tail the graceful shape of a lyre (an ancient stringed instrument similar to a harp). The body shape is described as relatively tall and short.
The fish are light beige/yellowish in color. A number of dark spots are often visible on the flank. The head and gill covers feature iridescent blue spots and stripes. The scales all over the body have very light blue shiny dots, which can also be found on the fins. The dorsal, caudal, and anal fins are edged with a transparent red color.
The temperament of Gymnogeophagus caaguazuensis is described as generally peaceful, although they can be somewhat territorial. They live naturally in small groups, and within these groups there is a clear hierarchy. They can be less tolerant of conspecifics, with parades and minor fights occurring until the hierarchy is established. They are predominantly diurnal. The swimming zone of this fish is mainly the bottom zone (benthopelagic).
Biotope
Gymnogeophagus caaguazuensis is native to South America, specifically Paraguay. The species is endemic to this country.
In its natural habitat, this fish prefers areas with bare sandy bottoms surrounded by rocky areas in small streams. During the rainy season, these streams can have a strong current. However, during the dry season and periods of low water, the species is found in pools and ponds with more or less stagnant water. The bottom generally consists of sand, pebbles, and rocks, with the presence of decaying organic material and roots.
The water characteristics in the natural habitat are as follows:
- Temperature: 22 – 25 °C
- pH (acidity): 6.5 – 8
- GH (hardness): 5 – 15
- Flow: Slow and stagnant
Water data collected in February at the species’ location showed a pH of 7.9, an electrical conductivity of 240 μS/cm, and a water temperature of 24.2 °Celsius.
The fish is found in areas characterized by dense vegetation, such as aquatic and marsh plants.
Diet
Gymnogeophagus caaguazuensis is an omnivore with carnivorous tendencies. In their natural environment, they feed on small invertebrates and organic material that they filter from the substrate. They are known for their behavior of filtering sand and sediment through their gills in search of food, which is characteristic of the Geophagini tribe. In the aquarium, this species can be fed a varied diet that includes both plant and animal matter.
Suitable aquarium food includes:
- High-quality dry food, such as flakes or granules specially formulated for cichlids.
- Frozen food, such as mysis, artemia, water fleas, and red mosquito larvae.
- Live food, if available and safe.
- Vegetables, such as blanched zucchini or spinach, can also be offered.
It is important to offer a varied diet to ensure that the fish receive all the nutrients they need. Common mistakes when feeding this species are:
- Overfeeding: This can lead to water quality problems and health issues in fish. Only feed them as much as they can eat in a few minutes.
- Monotonous diet: Feeding only dry food can lead to deficiencies. Ensure variety with frozen or live food.
- Incorrect food: Food that is too large or unsuitable for omnivores can lead to digestive problems.
To prevent these mistakes, it is advisable to feed the fish small amounts several times a day and to vary the menu.
The Aquarium
For the well-being of Gymnogeophagus caaguazuensis, a spacious aquarium is necessary. Because these fish naturally live in groups and form a social hierarchy, you need an aquarium with a capacity of at least 400 liters, which equates to a length of about 150 centimeters. It is wise to keep a group of at least five specimens. Solitary animals often languish, become shy, and are more susceptible to disease. In a group, they feel safer and display their natural behavior more readily.
The design of the aquarium starts with the substrate. Because these cichlids take bites of substrate material to filter food, a sandy substrate is an absolute requirement. Sharp pebbles or coarse gravel can damage their gills and hinder their natural foraging behavior. They also appreciate an environment with lots of plants, wood, and rocks. These elements not only create a natural look, but also provide necessary hiding places and sightlines. This allows the fish to mark their own territory without constantly seeing each other, which promotes peace within the group. Make sure that there is sufficient open swimming space in addition to the hiding places.
The water values do not need to be extremely specific, as long as they remain stable. The ideal temperature is between 22 °C and 25 °C. In terms of acidity, they tolerate a pH value between 6.5 and 8, and the hardness may vary between 5 and 15 dGH. Clean water is important for their health; try to keep the nitrate content low (below 50 mg/L) by changing approximately 20% to 30% of the water every month.
When choosing tank mates, you should take into account the modest and sometimes shy nature of this species. They combine well with other peaceful fish that are not too large or too active and appreciate the same water conditions. Avoid large, aggressive, or highly territorial species, as Gymnogeophagus caaguazuensis will hide and experience a lot of stress. It is also strongly discouraged to keep them together with other species of the same genus or closely related variants. This prevents unwanted crossbreeding (hybridization) and keeps the species pure.
Breeding Aquarium and Conditioning
Gymnogeophagus caaguazuensis is a larvivorous, maternal mouthbrooder, which means that the females carry the eggs and larvae in their mouths. Although they can be bred in the aquarium, breeding is considered moderate. Breeding can take place in a community aquarium, but success can vary. It is advisable to set up a special breeding aquarium to increase the chances of success and protect the young.
Dimensions and setup of breeding tank
An aquarium of at least 450 liters is recommended, especially if keeping a group. For a breeding pair or a harem (one male with several females), a smaller aquarium may suffice. The substrate should consist of fine sand, as these fish naturally filter sand. There should be plenty of hiding places, such as rocks, wood, and plants. A flat stone or other flat surface is essential, as the fish lay their eggs on it before the female picks them up.
To condition the fish for breeding, a varied and protein-rich diet is important. This includes frozen food such as mysis, artemia, and mosquito larvae, supplemented with high-quality dry food. Regular water changes (20-30% per month) help to maintain optimal water quality.
The ideal water values for breeding are similar to those for keeping the species. That is to say, a temperature of around 24 °Celsius and a pH of around 7.5. Light to medium-hard water is suitable. Small adjustments in temperature and water values can sometimes help to stimulate mating.
The Spawn
Gymnogeophagus caaguazuensis is oviparous (egg-laying) and a larvivorous, maternal mouthbrooder. This means that the eggs are initially deposited on a substrate, after which the female picks up the eggs and incubates the larvae in her mouth.
During courtship behavior, dominant males exhibit a distinctive trembling movement of their mouths. This behavior is considered a synapomorphy (a shared characteristic that indicates a common ancestor) of the mouthbrooding species within this genus.
The fish begin by depositing their eggs on a substrate, such as a flat stone. This behavior is similar to that of open-brooding cichlids. Shortly before the larvae hatch, the female takes the eggs into her mouth to continue incubating them.
The dominant males are polygamous and reproduce with multiple females each season. The mouthbrooding is larvivorous, which means that the female keeps the larvae in her mouth until they are free-swimming.
Raising the Young Fish
The young Gymnogeophagus caaguazuensis emerge after the female has incubated the eggs in her mouth. When the young are free-swimming, they are accompanied and protected by the female. They stay close to the female and seek her out for protection when they feel threatened. Parental care is mainly provided by the female. She keeps the young in her mouth and protects them from predators. The males can also play a role in protecting the young, but the primary care lies with the female.
The first food for free-swimming fry consists of small organisms such as infusoria or artemia nauplii. It is important to start feeding immediately after free swimming to support the growth of the fry. The fry should be fed several times a day, in small quantities. A schedule of 3-5 feedings per day is recommended. It is important to adjust the food to the size of the fry.
Regular, small water changes are essential for the health of the young fish. Change approximately 10-20% of the water daily to maintain water quality. Ensure that the new water is the same temperature as the aquarium water to prevent shock.
Conclusion
Gymnogeophagus caaguazuensis is a small, peaceful cichlid species native to Paraguay. They are known for their mouthbrooding behavior, whereby the female carries the eggs and larvae in her mouth. This species is generally suitable for aquarium owners who are willing to set up a spacious aquarium with a sandy bottom and sufficient hiding places. Their diet is omnivorous with a carnivorous tendency, and they thrive best on a varied diet.
Due to their social structure, it is advisable to keep these fish in groups, which requires a larger aquarium. Although they are considered peaceful, they can be somewhat territorial, especially towards other members of their species. Breeding is possible, but requires specific conditions and attention to the young. The species is currently considered endangered in the wild, which underlines the importance of responsible aquaculture.
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Frequently asked questions – FAQ
What are the main characteristics of Gymnogeophagus caaguazuensis?
Gymnogeophagus caaguazuensis is a small cichlid species that grows to about 12 cm in length, with males growing up to 15 cm. It is a mouthbrooder, with the female carrying the eggs and larvae in her mouth. They are generally peaceful and live in small groups in the wild.
Where does Gymnogeophagus caaguazuensis come from and what type of habitat does this fish live in?
This species originates from Paraguay, South America. In their natural habitat, they live in areas with bare sandy soils, surrounded by rocky areas in small streams. They are also found in pools and ponds with stagnant water, especially during the dry season.
What does Gymnogeophagus caaguazuensis eat, and what food is suitable for the aquarium?
Gymnogeophagus caaguazuensis is an omnivore with a carnivorous tendency. In the aquarium, they can be fed high-quality dry food, frozen food such as mysis and artemia, and possibly some vegetables. They naturally filter sand in search of small invertebrates.
What dimensions should the aquarium have for Gymnogeophagus caaguazuensis and what water values are ideal?
A minimum aquarium size of 450 liters (150 centimeters) is recommended, especially for groups. Ideal water values are a temperature of 22-25 °C, a pH between 6.5 and 8, and a GH between 5 and 15. A sandy bottom and sufficient hiding places are important.
Is Gymnogeophagus caaguazuensis suitable for breeding in an aquarium?
Yes, breeding is possible, although it is considered difficult. They are mouthbrooders, with the female keeping the eggs and larvae in her mouth. A varied diet and good water quality are essential for stimulating breeding.
Author
Since I bought my first second-hand aquarium when I was twelve, I have always had one or more aquariums. I even converted a garage into a breeding room where I had 50 aquariums containing around 10,000 liters of water. At the moment, I have two aquariums: a 1,250-liter Tanganyika aquarium and a 250-liter community aquarium with plants. For the past 10 years, I have been working on this website as a writer and photographer.
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