Glowlight tetra

Geographic Origin and Biotope: Essequibo River (Guyana). Swims in slow black streams (Blackwater) dense with vegetation and obscured by the dense forest canopy, with bottoms rich in dead leaves.

Taxonomy and Morphology: Glowlight Tetra (Hemigrammus erythrozonus). Small, delicate characin. Torpedo-shaped body, semi-transparent, largely devoid of marked liveries except for a very strong horizontal lateral line.

Social Behavior: Strictly a schooling fish (mandatorily in groups of at least 8-10). Very peaceful, a bit fearful if left in brightly lit tanks or with large fish. Among themselves the males chase each other mildly.

Coloration and Sexual Dimorphism: The glowing lateral line: an intense neon red/orange ray that cuts the fish from nose to tail. Males are slender, females decidedly more rounded (round if full of eggs) but equally bright.

Aquarium Setup: Dim lights! To enhance the neon colors, a tank with a black or dark bottom, floating plants to shield the light, lots of Cryptocorynes and amber water is needed. If the lights are too strong they become transparent and hide.

Diet and Feeding: Undemanding omnivores. Very small flakes, micro-pellets and abundant doses of very small live or frozen food (nauplii, daphnia, cyclops) essential to keep the "glow" alive.

Water Quality: Extremely hardy: they withstand harder pH than other tetras if adapted slowly, but colors explode at pH 6.0-6.5. Well-matured water (cycled filter) is indispensable to avoid fin rot.

Compatibility and Tankmates: The best friends of almost all dwarf fish. Perfect for "Nano" tanks with Neocaridina shrimp (rarely prey on the young), Otocinclus, Rasboras, Dwarf Gouramis and Apistogramma. Never keep with Angelfish (they will be prey).

Aquarium Reproduction: Reproduction accessible to novices. They scatter dozens of micro-eggs among the fine foliage after intense morning courtships ("Egg-scatterers"). They immediately devour the brood if not removed.

Risks and Diseases: Vulnerable to wasting away due to voracious tankmates (e.g. Tiger Barbs, Giant Danios) that steal food and stress the group leading them to starve holed up in a corner.