Silver Hatchetfish

The genus Gasteropelecus includes three species that are very similar to each other. The Silver Hatchetfish, for example, is almost identical to the Common Hatchetfish (Gasteropelecus sternicla), differing only in size — it reaches about 3 cm in length. The fish's body has a typical shape with a pronounced, strongly flattened belly. The coloration is silvery, the back is gray, adorned with rows of horizontal black and yellow stripes running along the lateral line. The fins and tail are short, translucent.

The natural habitat of this species is in South America, specifically in Brazil, in the lower Amazon River basin, including its large tributaries Tocantins and Guamá. The fish prefer calm river sections, backwaters, and floodplain lakes. They are often found in open waters with islands of floating vegetation, where they usually gather in large groups.

This is a peaceful schooling fish. Due to its small size, it cannot compete with more active species, so their cohabitation should be avoided. It coexists perfectly with various small tetras and cichlids, Corydoras catfish, and other non-aggressive South American species of comparable size.

For a school of ten fish, an aquarium of at least 50 L will be optimal. The Silver Hatchetfish spends most of its time near the water surface, so decorative arrangement does not play a decisive role for it. It is sufficient to provide several shelters in the form of groups of floating plants. The aquarist can choose the rest of the decor at their discretion, or based on the needs of other inhabitants. The presence of a lid on the tank is mandatory to prevent accidental jumps by the fish. It is widely believed that hatchetfish are capable of significant jumps out of the water, supposedly thanks to their pectoral fins resembling miniature wings. Although they, like many other fish, can indeed jump, it usually does not come to "flights." This is a relatively undemanding species. Long-term and successful keeping is possible by maintaining stable water parameters within acceptable limits of temperature and hydrochemical indicators. High water quality, i.e., a low concentration of pollutants, is ensured by the uninterrupted operation of the installed equipment, especially the filtration system, as well as regular performance of mandatory care procedures: weekly partial water changes, removal of organic waste, and similar actions.

In natural conditions, the basis of these fish's diet is small insects. However, acclimatized individuals, as well as fish bred in captivity, adapt to dry foods. It is important to note that all offered foods must remain on the water surface, as any sunken food will remain uneaten.

Unfortunately, at the time of preparing this article, no successful cases of breeding these fish in home aquariums have been recorded. In their natural environment, their spawning is closely linked to seasonal changes and involves migration to flooded areas of tropical forests during the rainy season. For the average aquarist, recreating such conditions is quite a challenging task.

Maintaining a stable biological system, providing a balanced diet, and eliminating stress factors (e.g., harassment by aggressive tank mates) are the best guarantees for preserving fish health. If the first signs of illness appear, the first thing to pay attention to is precisely these three aspects, as deviations have likely occurred in one of them. As a rule, eliminating the problem leads to self-recovery. However, if the immune system proves to be insufficiently strong, medicinal treatment may be required. More detailed information on symptoms and treatment methods can be found in the "Diseases of Aquarium Fish" section.

When purchasing, choose active individuals with clean fins and no visible damage to the body. It is important to ensure that the fish swim in the upper layers of the water and exhibit the natural shyness characteristic of this species. Avoid specimens with signs of emaciation, sunken bellies, or film on their scales, as these fish are sensitive to stress during transport and changes in keeping conditions.

Since similar species of the genus Gasteropelecus may be sold under the name "silver hatchetfish," it is recommended to carefully examine the pattern on the body. Healthy fish should have clear horizontal lines and not show signs of apathy. Before purchasing, clarify what the fish are fed in the store, as recently arrived individuals may refuse dry foods, preferring live or frozen alternatives.