Gasteropelecus maculatus – Spotted Hatchetfish
Gasteropelecus maculatus was first described by Steindachner in 1879. The fish belong to the family Gasteropelecidae, also known as Hatchetfish. The name is derived from Greek and Latin, where “gaster” means “belly” and “pelekus” means “axe”. This refers to the characteristic shape of the fish, which is reminiscent of an axe. The species name “maculatus” means “spotted” in Latin, which refers to the spots on the fish’s body. Their common name is Spotted Hatchetfish.
Synonyms: Thoracocharax maculatus, Thoracocharax brevis, Thoracocharax magdalenae, Thoracocharax maculatus magdalenae.
Description
Gasteropelecus maculatus, also known as the Spotted Hatchetfish, has a characteristic body shape reminiscent of an axe. The body is laterally flattened and has a noticeably convex abdomen, contributing to its axe-shaped appearance.
The head and flanks of this fish are predominantly silvery in color. The scales are clearly visible and have a dark edge, creating a net-like pattern. A prominent black horizontal line runs from the gill covers to the caudal peduncle, followed by a series of three or four lines of dots. In addition to the black horizontal line and the dots, the base of the dorsal fin has a black marking that can vary in intensity between individuals
The fins of the Gasteropelecus maculatus are generally transparent or light-colored, matching the silver color of the body. This species of fish can reach a maximum length of about 9 centimeters.
Differences between Males and Females
Distinguishing between males and females in Gasteropelecus maculatus can be difficult because there are no pronounced physical differences. However, females tend to have a slightly rounder and fuller abdomen, especially when carrying eggs. During the mating season, males may display more intense colors and display territorial behavior or courtship rituals to attract females.
Behavior and Temperament
Gasteropelecus maculatus is a peaceful and social fish that thrives best in groups of six or more individuals. They often stay close to the water surface, where they catch insects and small invertebrates. This fish species is generally peaceful and can live well with other small, peaceful fish species. They are not aggressive but can be shy and tend to jump when they feel threatened, which requires a well-covered aquarium.
Lifespan
In a well-maintained aquarium, these fish can have a life expectancy of approximately 5 years.
Biotope
The Spotted Hatchetfish occurs naturally on the border of Central and South America. They are found in Colombia and Panama. These fish mainly live in rivers and streams. They are often found in slow-moving or stagnant waters such as rivers, streams and flooded areas. Specific rivers where they occur include the Rio Caqueta and the Magdalena River.
Natural habitat
The natural habitat of the Gasteropelecus maculatus consists of areas with dense vegetation, especially along the banks of rivers and in flooded forest areas. This environment offers many hiding places and potential spawning grounds. The waters they live in can be either clear or slightly murky, and they usually stay close to the water’s surface where they catch insects and small invertebrates.
The soil of their natural habitat often consists of a mixture of sand, mud and organic matter such as leaves and branches. This substrate provides a suitable environment for the development of microorganisms that are part of their diet.
Diet
In their natural habitat, they feed primarily on a carnivorous diet. They mainly eat insects, small crustaceans, worms and other invertebrates that they find on the water surface
Black mosquito larvae and fruit flies are best given as food, but dry food is also accepted. The food that falls down is no longer eaten.
The Aquarium
To keep a small group of Gasteropelecus maculatus, also known as the Spotted Hatchetfish, an aquarium of at least 150 liters and 100 centimeters in length is recommended. The aquarium should be decorated with many floating plants and tall aquatic plants that reach the water’s surface. This provides hiding places and helps the fish feel safe. Make sure there is sufficient swimming space on the surface.
Use fine gravel or sand as a substrate. This helps to mimic a natural environment. The substrate does not matter for the fish. They mainly swim in the upper water layers.
Make sure the aquarium is properly covered, as these fish are known for their jumping behavior.
Water parameters
The best water conditions for Gasteropelecus maculatus in the aquarium are a temperature between 22 and 28°Celsius. The pH for a community aquarium can be between pH 6.0 and 7.5. The hardness between GH 4 and 12.
Breeding Gasteropelecus maculatus – Spotted Hatchetfish
Breeding of Gasteropelecus maculatus is challenging and requires specific conditions. Although there are reports of successful breeding in a regular aquarium, it is usually recommended to use a special breeding aquarium to achieve the best results.
A breeding aquarium of at least 50 liters is recommended to provide sufficient space for the fish and their offspring. The water should be soft and slightly acidic, with a pH of 5.5-6.5 and a temperature of about 25°C. Dim lighting is recommended to reduce stress and simulate a natural environment. Provide sufficient floating plants where the parents deposit the eggs.
Use a sponge filter or other soft filter to maintain a gentle water flow and protect the eggs and hatchlings from being sucked in.
Conditioning
Before spawning, adult fish should be well fed with a diet rich in live foods, such as black mosquito larvae, fruit flies, and brine shrimp nauplii. This helps to get the fish in optimal condition for breeding.
A breeding group can consist of multiple males and females, but a ratio of one male to two females is often recommended to increase the chance of successful fertilization.
The Spawn
During the spawning season, males may display more intense colors and display territorial behavior or courtship rituals to attract females. This can result in a more pronounced black horizontal line and dots on their body.
Now darken the aquarium. The next morning the fish chase each other fiercely. The eggs are then deposited between the roots of the floating plants. The eggs then fall down.
The parents eat the eggs. It is therefore important to remove the parents after laying the eggs. The eggs are small and transparent, which helps them go unnoticed by potential predators (and parents).
Raising the fry
The eggs of Gasteropelecus maculatus hatch after about 30 hours. The young begin to swim freely after 5 days. There is no parental care in Gasteropelecus maculatus. After laying the eggs, the parents must be removed to prevent them from eating the eggs.
The young should initially be fed with infusions or the finest dust food.
Video
Author
John de Lange
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