Lemon tetra

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: plant safe.

Feeding

Undemanding. Flake food, micro pellets, frozen bloodworm, frozen brine shrimp, frozen daphnia. Feeds in the midwater column. Not competitive at feeding time; won't outcompete anyone but also doesn't get pushed around. Twice-daily feeding in moderate amounts. Color improves with a varied diet. Live baby brine shrimp is a treat that brings out feeding behavior.

Compatibility

• Peaceful schooling tetra that fits into any community with non-aggressive species. No nipping, no territorial behavior, no drama.
• Schools best in groups of 8+ where the yellow coloration intensifies through competition between males. Small groups look washed out.
• Good companion for planted tanks, community tanks with dwarf cichlids, and any setup with similarly sized peaceful fish.
• The lemon-yellow body color with a red upper eye is subtle compared to neons or cardinals but in a big group against a dark background it's surprisingly attractive.

Origin and habitat

Hyphessobrycon pulchripinnis, the lemon tetra, is a small characin from the Tapajos basin in central Brazil, a major clearwater tributary of the lower Amazon. Ahl described it in 1937 from aquarium imports of unknown origin, and the fish reached the hobby a few years before that; its wild range was not pinned down until Gery's 1980 redescription tied it to the middle and lower Tapajos. The species name, from the Latin for beautiful fin, points to the black-and-yellow dorsal and anal fins. Classification is in flux, as with several Hyphessobrycon: it has long sat in the family Characidae, and recent revisions of the American characins place parts of the genus in Acestrorhamphidae, so sources disagree on which applies. The body is translucent with a warm lemon-yellow cast that deepens in healthy, well-kept fish, and the standout feature is the eye, whose upper half glows bright red. Records give a maximum standard length of under 4 cm, while aquarium sources commonly quote about 5 cm in total length. An albino form is also traded.

Breeding

An egg scatterer of moderate difficulty. A conditioned pair spawns at first light in a separate, dimly lit tank with soft, acidic water and fine-leaved plants or a spawning mop, scattering up to a couple of hundred eggs. The eggs are light-sensitive, and the adults eat them, so the tank should be kept dark and the parents removed afterward. Eggs hatch within a day or so, and the fry need infusoria-grade food before moving on to baby brine shrimp. Hobbyists breed lemon tetras less often than many other tetras, mainly because farmed fish are cheap and always available.

Common problems

The usual disappointment is colour: in a bare, brightly lit tank a lemon tetra looks plain, but over dark substrate, under warm light, in tannin-stained water, and in a decent-sized group, the yellow and the red eye come alive. Otherwise they are hardy, with ich mainly a risk on stressed new fish and fin rot uncommon outside poor water. They are among the longer-lived small tetras, often reaching several years, and older fish slowly lose colour intensity.

Bioload

Further reading

• Why your angelfish ate your neons
• The schooling number matters more than you think