搏氏企鹅鱼 · False Penguin Tetra

Overview

Thayeria boehlkei is the penguin tetra most often encountered in the trade. It swims with the head tilted upward, and a bold black stripe runs from the lower tail lobe along the flank to the gill cover. Commercially bred specimens dominate aquarium supplies.

Distribution & habitat

The range is probably limited to parts of the upper Amazon in Peru and the Araguaia in Brazil. It may use diverse habitats, from wetlands rich in submerged plants to forest streams with dense bankside cover but little aquatic vegetation. These habitat descriptions remain partly inferential.

Aquarium setup

An aquarium around 60 × 38 × 30 cm, or 68 liters, accommodates a small group; a larger aquarium with more fish is preferable. Dense planting, roots, branches, and smooth stones work well. Dark substrate and floating plants provide shade. Sand, wood, and leaves under subdued lighting are another option, with shade-tolerant plants if desired.

Farmed fish usually adapt to a broad range of chemistry, from soft, acidic water to harder, more alkaline conditions. Regular maintenance remains necessary.

Diet & feeding

The natural diet consists mainly of insects, worms, crustaceans, and other small invertebrates. Captive fish readily take prepared foods. Alternate quality flakes or granules with small live and frozen items such as bloodworms, Daphnia, and Artemia.

Behaviour & compatibility

Choose peaceful companions rather than large or excessively active fishes. Small tetras, pencilfishes, suitable dwarf cichlids, and small catfishes are possible partners. Keep at least six individuals, preferably ten or more. With adequate numbers, social squabbling is directed mainly within the group and occasional fin-nipping is less likely to emerge.

Sexual dimorphism

Adult females have rounder abdomens and generally somewhat less intense color than males.

Breeding

Breeding is relatively easy. Use a dim, separate aquarium with fine plants, mops, or protective mesh for the semi-adhesive eggs, plus gentle sponge filtration. Farmed parents are less demanding about chemistry than many other tetras, although slightly acidic to near-neutral water is preferable. A temperature increase is reported to help trigger spawning.

A group of approximately six fish per sex can spawn. Alternatively, condition males and females separately, then introduce a gravid female and a well-conditioned male in the evening. Spawning usually follows the next morning. A female commonly produces around 1,000 eggs and may produce as many as 3,000. Heavy milt release can sometimes make an immediate partial water change necessary.

Remove the adults once eggs are present. Hatching takes about 12–24 hours, and free swimming follows three or four days later. Begin with infusoria-sized foods, then offer microworms and Artemia nauplii. Eggs and early fry are light-sensitive, so darkness is preferable.

Notes

In Thayeria obliqua, the dark marking tapers upward and disappears before reaching the dorsal fin. In T. boehlkei, it continues forward to the gill cover. Similar trade names and the shared tilted swimming posture alone do not establish identity.