圣企鹅鱼 · Penguin Tetra

Overview

The head-up swimming posture of Thayeria obliqua gives it a recognizable penguin-like appearance. Identification still matters because a more common relative shares the trade name. In this species the dark marking from the lower tail lobe narrows upward and disappears before reaching the dorsal fin.

Distribution & habitat

It is native to Brazil’s central Amazon region, the Tocantins basin, and the Guaporé River. Forest streams and tributaries provide habitat, probably with substantial vegetation along their margins.

Aquarium setup

An aquarium around 60 by 38 by 30 cm is only just adequate for a small group; more space allows a larger social group. A planted display can use dark substrate, wood, smooth stones, and floating shade. Alternatively, sand, roots, and leaves create a forest-stream appearance with lightly stained water. Use low-light plants if desired and maintain the water consistently.

Diet & feeding

Provide regular small live or frozen meals such as bloodworms, water fleas, and brine shrimp, together with accepted flakes or granules. Variety supports condition and coloration.

Behaviour & compatibility

Keep at least six, preferably ten or more. A larger group channels interactions toward conspecifics and limits potential fin-nipping. Quiet, suitably sized tetras, dwarf cichlids, and catfishes are more appropriate companions than large or boisterous competitors.

Sexual dimorphism

Adult females tend to have fuller bellies and slightly less intense coloration than males.

Notes

Compare the complete stripe rather than relying on a penguin-tetra label. In Thayeria boehlkei, the broad dark band continues along the flank to the gill cover, unlike the shorter upward-tapering marking here.