Formosa

This tiny fish is extremely small. Males are noticeably slimmer and smaller than females, by about one and a half times. Females, on the other hand, appear plumper, with rounded bellies. Their coloration is predominantly light, with a slight yellowish tint. A distinctive brown stripe runs along their entire body from head to tail.

Its natural habitat is marshy waters in North America, in lands now belonging to the states of Florida and South Carolina. The fish is undemanding regarding its keeping conditions.

This peaceful, schooling, and timid fish, due to its tiny size, is ideal for keeping in a separate species-only aquarium. They prefer to live in a community of their own kind, and the introduction of other small fish is only permissible if these fish are also very small. Formosa, unfortunately, often falls victim to aggression even from species generally considered peaceful.

Setting up an aquarium for these fish does not require much effort. If there are enough rooted and floating plants that take on the functions of water purification and oxygenation, then a filter, heater (the fish tolerates temperatures down to 15°C well), and aerator can be omitted. The aquarium design should include various shelters created from natural or artificial decorative elements.

This omnivorous species readily accepts a variety of foods: dry mixes, as well as fresh, frozen, or live foods such as bloodworms, daphnia, or artemia. It is important to ensure that the particle size of the offered food is small enough for Formosa to easily swallow them. It is recommended to remove all uneaten food remnants to prevent contamination of the aquarium water.

Breeding is only possible in warm water, so the use of a heater will be very useful here. Spawning can begin at any moment, and new generations can appear year-round. A peculiarity of this species is that fertilized eggs develop inside the female's body, and the fry are born fully formed. This adaptation is an effective evolutionary strategy for protecting offspring. However, parents do not show care for their offspring and may even eat the fry, so it is recommended to immediately move the young to a separate tank. They should be fed microscopic food, such as Artemia nauplii.

Diseases are extremely rare in this species. Outbreaks of disease are only possible under extremely unfavorable environmental conditions, through contact with infected individuals, or as a result of injuries.

When choosing Formosa, pay attention to the overall activity of the fish: healthy individuals should be active and show interest in their surroundings. Avoid specimens with signs of emaciation, sunken bellies, or scale damage. It is important to carefully inspect the fins for the absence of plaque, ulcers, or signs of rot, as any deviations from the norm may indicate bacterial infections or the effects of transport stress. — Assess the cleanliness of the water in the store's aquarium, as poor keeping conditions often lead to hidden diseases. — Ensure that the fish do not show signs of apathy and do not constantly stay at the surface or in the corners of the aquarium. — Check for visible parasites on the body, such as white spots or patches, which may indicate the presence of infestations.