Common Zacco

Although adult individuals of this species can grow up to 20 cm in length, their size most often does not exceed 13 cm. It is noted that males are larger and have more intense coloration compared to females. During the breeding season, their coloration becomes particularly striking: bright orange stripes appear on a gray-blue background. These same warm hues are characteristic of the belly, anal, pelvic, and pectoral fins, which acquire a rich blue color. The anal fin in both sexes is noticeably elongated.

Common Zacco is widely distributed in East Asia, including territories of China, Korea, Japan, Taiwan, and northern Vietnam [animalia.bio]. In nature, it primarily inhabits flowing bodies of water, such as rivers and mountain streams with clear, oxygen-rich water [aquaportail.com]. Adult individuals prefer shallow waters with fast currents, where they stay near the bottom, often hiding among rocks [animalia.bio].

This fish is characterized by its activity and peaceful temperament. When young, they prefer to live in schools, which serves as protection. However, as they mature, the need for constant company of their conspecifics disappears. They get along well with other non-aggressive species of comparable size due to their peaceful nature. It is important to remember that their excessive activity can cause discomfort to slower tank mates.

For a group consisting of 4–5 individuals, the optimal aquarium volume will be no less than 200 L. Common Zacco feels most comfortable in conditions of moderate current, so the presence of an efficient filter will be very useful. A powerful filtration system, coupled with regular aquarium cleaning and partial water changes, helps maintain a low level of pollution. Since the fish originates from subtropical regions, it requires relatively cool water; prolonged exposure to temperatures above 22–23°C is unacceptable. The aquarium decor can be arbitrary, the main thing is to provide enough free space for active swimming.

In their natural habitat, Zacco feed on zooplankton, various algae, fry of other fish, and detritus. In aquarium conditions, they are easily accustomed to alternative foods, including popular dry products such as flakes or pellets.

In the natural environment, reproduction occurs in two stages: spring (February–April) and summer (June–August) [animalia.bio]. The fish are egg-layers, do not care for their offspring, and often bury their eggs in the substrate by fanning with their tails [animalia.bio]. Successful breeding in aquarium conditions is difficult due to specific spawning requirements, including imitation of seasonal temperature changes and the presence of strong currents [aquariumdatabase.nl, aquainfo.nl].

No specific diseases exclusively characteristic of this species have been identified. Like other members of the carp family, this species is sensitive to water quality and oxygen levels. If keeping conditions are violated, especially with poor filtration or overpopulation, the fish are susceptible to bacterial infections, fungal skin lesions, and fin rot.

Disease prevention is based on maintaining water cleanliness, ensuring a strong current, and regular partial water changes. Due to their high activity and tendency to jump, fish can sustain mechanical injuries, so a tight-fitting lid is a mandatory safety requirement. If signs of stress or damage appear, it is necessary to check water parameters and exclude the presence of aggressive tank mates.

When purchasing, select active, mobile individuals with clean fins and no visible skin damage [aquariumdatabase.nl]. It is important to consider that young fish may be peaceful, but as they mature, they exhibit pronounced territoriality and predatory tendencies, so they should not be kept with small species [aquainfo.nl]. Fish are prone to jumping, so a secure aquarium cover must be provided during transport and subsequent keeping [aquainfo.nl].