Other scientific names: Alfaro acutiventralis, Alfaro amazonum, Petalosoma amazonum, Petalosoma cultratum, Petalurichthys amazonum, Petalurichthys cultratus
Alfaro cultratus, also known as the knife-edged livebearer, belongs to the family Poeciliidae. This fish is distinguished by its hardiness and unpretentiousness, which means it does not have special requirements for keeping conditions. Although it is not often found in retail chains, this species is quite common among amateur aquarists.
- Required aquarium volume
- 50 L
- Size in aquarium
- 7 cm
- Temperature
- 24 – 28 °C
- Temperament
- Territorial (often aggressive)
Description
The appearance of this fish is quite simple: its coloration is light gray. From certain angles, a bluish tint can sometimes be noticed. The fins remain translucent. The body is slightly elongated, with males usually being more slender than females, who, in turn, are noticeably larger.
Habitat
This species is widespread in the waters of Central America, including the territories of Costa Rica, Nicaragua, and Panama. It prefers to inhabit small rivers, streams, canals, and backwaters where the current is moderate or slow. Requirements for conditions: no special requirements.
Behavior and Compatibility
The fish sometimes shows aggression towards individuals of its own species, but serious injuries are extremely rare. It is compatible with other species if they are larger than it. It is not recommended to keep small fish with Alfaro cultratus.
Care and Maintenance
Alfaro cultratus adapts well to a wide range of pH and GH values, which significantly simplifies water preparation for the aquarium. It is usually sufficient to use tap water that has been left to stand for about a day. The minimum equipment set includes a filter, aerator, heater, and lighting system. Weekly maintenance involves replacing 15–20% of the water volume with fresh water. Substrate cleaning is performed as it becomes silted. In terms of decor, it is recommended to create areas with lush vegetation and open spaces for swimming. Floating plants are also welcome. Roots, snags, and rock formations can be used as additional decor.
Diet
The diet can include any dry, frozen, or live foods. For home keeping, the optimal solution is to alternate several types of food from trusted manufacturers throughout the day. Feeding is recommended 2-3 times a day, offering an amount that the fish can eat in 5 minutes. It is important to promptly remove any uneaten leftovers. Aqvium flake food for aquarium fish is available on Ozon and has a rating of 4.9, making it a bestseller. This food is suitable for most aquarium fish, and its raw materials are produced according to new European Union standards (EU 2018/848). It contains vitamins A, C, D3, E, as well as Omega 3-6. It can be purchased on Ozon.
Breeding and Reproduction
Breeding Alfaro cultratus in a home aquarium is not a difficult task. No special conditions for spawning are required, as it can occur in the community tank at any time of year. An adult female can produce up to 100 fry. Upon finding them in the aquarium, it is advisable to transfer the young to a separate tank, for example, a three-liter jar, and feed them micro-food.
Diseases
In a well-balanced aquarium ecosystem, disease outbreaks are extremely rare. Health problems arise in neglected cases when there are high levels of pollutants, irregular or poor-quality feeding, or contact with already sick fish. More detailed information on symptoms and treatment methods is available in the “Aquarium Fish Diseases” section.
How to choose
When choosing Alfaro cultratus, attention should be paid to the overall activity of the individuals in the aquarium: healthy fish should swim quickly, show curiosity, and not exhibit signs of timidity or apathy. It is important to carefully inspect the body for the absence of injuries, ulcers, white spots, or signs of fungal infections, as the species is sensitive to water quality and bacterial infections. Avoid buying fish that stay at the bottom or look emaciated, as this may indicate health problems or stress from improper keeping conditions in the store. Since these fish are active swimmers, it is recommended to purchase a group of several individuals to reduce their stress during transportation and adaptation.
Frequently asked questions
The essentials: size, tank volume, water parameters and care
How big does Alfaro cultratus get?
An adult reaches 7 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.
What size aquarium does Alfaro cultratus need?
The minimum recommended volume is 50 L. A smaller tank speeds up nitrate build-up and raises stress levels.
What water parameters does Alfaro cultratus need?
Temperature 24–28 °C, pH 6–8, hardness 5–20 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.
How long does Alfaro cultratus live?
Around 5 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.
Is Alfaro cultratus aggressive?
Temperament: territorial (often aggressive). Keep this in mind when choosing tank mates.
How many Alfaro cultratus should be kept together?
Recommended setup: schooling (usually from 5–6 individuals and more). Ignoring this is a common cause of stress and disease.
What does Alfaro cultratus eat?
Diet type: any (universal). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.
What is the scientific name of Alfaro cultratus?
The scientific name of the species is Alfaro cultratus, family Poeciliidae. It also appears in the literature as: Alfaro acutiventralis, Alfaro amazonum, Petalosoma amazonum.
