Parosphromenus filamentosus

A conspicuously extended caudal filament; the inner parts of the unpaired fins are reddish brown, with whitish-blue edges.

Needs very soft, acidic water.

Social behaviour and territory

Does not form tight schools. Pairs can be used for breeding; groups need caves and cover. Watch nest guarding and subordinate fish.

Offer tiny, suitably sized live foods. Dry food is unreliably accepted; confirm the fish actually eat.

Sources