The Glowlight Tetra and the Fire Tetra

Learn About the Strange History of the Glowlight Tetra

The Glowlight Tetra amazing comunity aquarium fish

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The Glowlight Tetra or alternatively called Fire Neon is a hardy little fish and has a long and confusing history. Today it is not conclusive if the fish in your tank is correctly identified as Hemigrammus erythrozonus, the accepted classification. This South American species comes from the Guianas, the Amazon Basin, Rio Sao Francisco, and Rio Paraguay.

It was first discovered and identified by Dr. Durbin in 1909, though it was not initially imported widely for aquarium use. In 1939, Hemigrammus Erythrozonus Durbin was identified as belonging to the Characidae family and its place of origin identified as Guyana. The fish begin to be widely imported to Europe and the United States as the Fire Neon. Later Fraser-Brunner raised a question in regards to this fish, also known by the name Hyphessonbrycon Gracilis since its importation into North America as the Glowlight Tetra, which has never been entirely answered.

Perhaps there are several varieties possessing the typical stripe of the Fire Neon/Glowlight Tetra, which crossbred during initial attempts at domestic breeding. The investigation of aquarium breed specimens in the 1970’s  brought to light that the characteristic for the genus Hemigrammus (that is scales on the caudal fin) does not hold true for this species. It is also difficult to determine to which of the two general this species might belong.

Some of the investigated tank raised specimens, which without doubt all represented the same species, had a caudal fin without scales (genus Hyphessobrycon), a large number (17 of the 42 used in the study) stood just on the edge between the two species and genera—that is, with two rows of scales just past the roots of the tail—while 16 specimens showed a normally scaled caudal fin (genus Hemigrammus). Does this mean anything at all with regards to breeding this fish? Not at all, just another bit of trivia for those Aquarium Society networking events, a bit of trivia not many know or probably even care to know!

It is sometimes unbelievable how different fish can appear when seen in ideal surroundings, as against being huddled together in a corner of a bare tank, frightened and unhappy. Here we have a case in point. The Glowlight Tetra can be a drab, colorless fish, or a fiery, startling beauty that glows brilliantly.

Seen in soft peaty water in a beautifully planted aquarium, having a dark background and lit from above, a shoal of these little gems is a sight not easily forgotten. This fish is at its best when on its own or with other small fish. The latest versions of the Glowlight Tetra from commercial breeders and fish farms is far more stable than wild caught specimens, however, and can be a welcomed addition to a calm community tank, with full-color effects.

The body is translucent; a vivid red stripe runs across the flanks from the eye to the base of the tail. The dorsal fin has red in the forward part of the fin itself. The other fins are clear, except for small white tips. The body is fragile, thin and almost transparent. The back is an olive-yellow-green color. Any deviation in the shape of the body from the Neon Tetra is not worth mentioning, in size and shape they are virtually identical. 

Most of what is said about the Neon Tetra applies to the Glowlight Tetra, except that the Glowlight Tetra is much easier to breed, same methods apply, but they are far more forgiving to beginner breeder mistakes. The male is slimmer than the Female, who is much plumper at breeding time, but always slightly more pronounced in the belly.

When young, males may sometimes be identified, by the anal fin characteristic Characin hook; this often gets caught up in a fine net. In adult specimens sex is obvious, the females being both larger and much deeper and fatter in the bellies. They are not particular as to the size of the tank, the composition of the water or even to environment and food. They can be happy in temperatures from 68F to 79F and will survive a much wider range of temperatures and water conditions than will the Neon Tetra.

The Glowlight Tetra or Fire Tetra is an easy to keep fun addition to a small well-planted community aquarium. If you have had difficulties keeping schools of Neon Tetra’s alive, it could be the water conditions in your area. Rather than the constant struggle of weekly water testing’s and adjustments, why not try this hardy little alternative, they live through practically everything!