Gymnocorymbus bondi · Silver Tetra

Overview

A hardy social tetra, Gymnocorymbus bondi has active juveniles with reddish fins that become plainer as they mature. Its generally peaceful nature comes with a reputation for fin nipping, so long-finned companions are unsuitable.

Distribution & habitat

It occurs in small tributaries and streams of the Orinoco basin in Colombia and Venezuela.

Aquarium setup

Dense planting, dark substrate, and floating cover help this shy fish settle. Adequate group size remains important; additional décor alone cannot compensate for isolation or a very small group.

Diet & feeding

An adaptable omnivore, it accepts prepared, live, and frozen foods. Include vegetable foods such as spirulina flakes or blanched spinach; otherwise soft-leaved aquarium plants are more likely to be nibbled.

Behaviour & compatibility

Keep at least six to eight; smaller groups may become withdrawn. Similar-sized peaceful tetras, small catfish, and suitable mild cichlids are possible companions. Avoid long-finned guppies, bettas, and angelfish. Juvenile activity is not aggression, but nipping still matters.

Sexual dimorphism

Mature males tend to be slightly smaller and slimmer than females.

Breeding

Breeding is relatively easy in a separate dim aquarium. Fine-leaved plants or spawning mops receive adhesive eggs; mesh can also protect them from adults. Condition fish with live and frozen foods. Either a group or a well-conditioned pair can be used, with sexes conditioned separately when selecting a pair.

Ready fish may spawn the following morning. Remove adults as soon as eggs appear. Hatching takes roughly 18–36 hours, followed by free swimming several days later. Start with infusoria-sized food, then introduce microworms and Artemia nauplii. Eggs and young fry are light-sensitive, so keep the setup dim.