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A person always involuntarily seeks a correspondence between the living creature in question and its name, especially if it is imaginative. Therefore, when you first saw the green neon, you involuntarily wonder: why "neon" and why it is "green"? And indeed: the usual luminous band, characteristic of red or blue neon, is almost none, and the green tones in coloring are almost invisible.
The solution to this puzzle, apparently, should be sought in our past forty years ago. In that glorious time for Russian aquarists, lovers of exotics got at their disposal a beautiful fish - blue neon and, apparently, the enthusiastic imagination of aquarists in every new fish wanted to see another species of neon. Most likely, it is because of this in the vocabulary of fans of dwarf characynids confidently included such names as "green", "black" and "Peruvian" neons.
Green neon has one more name - "kostelo". The etymology of this name is more understandable: in the days of the unforgettable memory of MN Ilyin in special literature, the species was designated as Hemigrammus costelo, and only later acquired the accepted Latin name, Hemigrammus hyanuary (Durbin, 1918).
Green neon is a typical representative of the hemigrammus genus. Stretched, length up to 3.5 - 4.0 cm, slightly flattened laterally body, rounded snout, terminal mouth. The color is mostly silvery and, like many fish of this genus, has a weak greenish reflection. Iris of the eye is not colored.
Directly under the middle line along the body there is a narrow bright strip, the color of which varies from yellow-orange to greenish, depending on the angle of incidence of light. Under this strip immediately behind the abdominal cavity begins a dark spot, the color of which to the tail thickens to black. The spot reaches the middle of the caudal fin, where it is trimmed with whitish edging. Due to this, the tail part of the fish body appears to be elongated.
Above the spot in the space between the fat fin and the tip of the caudal peduncle is a bright sparkling "flashlight" (a mirror, a spark - call it whatever you want). This feature is characteristic of many hemigrammus. Most often the flashlight is very small and can be seen only from the back of the hemisphere of the review, but in green neon it consists of at least three reflecting surfaces, due to which this luminous spot is clearly visible from any direction. Moreover, depending on the angle of view, its color varies from orange to golden.
Fins are colorless, with the exception of the anal, on which there are whitish spots in the anterior and posterior parts.
The color of males and females does not differ. Determine the sex can only be in sexually mature fish: the males are lagging behind the females in size and volume of the abdomen. A reliable sign of the male could be considered his ability to cling to the anal fin for the fabric of the net after transplanting, but this does not always happen. Thus, if the fish hangs on the anal fin under the overturned net - this is exactly the male, and if not - it does not necessarily mean that it is a female.
For a long time I could not "establish mutual understanding" with Hemigrammus hyanuary. My repeated purchases ended in failure: most often the males either died prematurely for various reasons, or behaved indifferently in the spawning man.
In 1998, I made another attempt: I asked the famous Bulgarian amateur Haratsinov D. Penev to send me ten green neon. When they grew up, it turned out that among the fish obtained there were 6 females and 4 males. But my joy was premature again: soon, along with the red-banded rasbori (Rasbora pauciperforata), acquired on the market, I brought into the aquarium some sort of Asian fish infection, similar in appearance to ichthyophthirius. And most of all, the males of green neon suffered again.
This time, one experienced Moscow haratsincher rescued my losses. And it turned out that on this the band of failures with green neon for me ended. Then everything went well.
The spawning of green neon begins with the advent of twilight. Motionless in usual time, the fish are animated and begin to move along the walls of the spawning ground. The leading role is played by the female. The male follows it steadfastly, being below from 3 to 4 centimeters. If the female stops, as if to catch her breath, the male also stops, demonstrating amazing synchronism of movements. When the pause is delayed, the male initiates the movement himself, trying to entice the female. No jerks, strikes in the hull or other "power" tricks to beat the caviar out of it, the male does not apply.
At a certain moment, when the movement is particularly energetic, the male is pressed against the female side. Some time the couple sails together, and the male obviously directs the partner in a circle. Then there is a mutual push, the fish fly apart, and the caviar flies anywhere.
Mating occurs in a zone free from vegetation at a depth of 10 to 15 centimeters, but not at the bottom. No spawning substrate fish are not used and are not interested. However, in the spawning nevertheless it is necessary to place 1 - 2 small bushes, hiding behind which the fish could feel safe in the daytime.
Caviar, and then larvae, must be protected from bright light for five days, until they form eyes. In the future, the darkening can be removed and begin to feed, even if you are not entirely sure that the larvae swam and switched to active feeding.
The best starting feed - "home" infusoria-shoe or pond dust. In the winter, the brackish-water rotifer Brachionus plecatilis will help out. Such a small forage is needed for the first 3 to 4 days, and then the larvae can be transferred to the freshly bitten nauplius of Artemia.
In general, feeding fry does not have any special features. With good care (a variety of feeding, frequent water changes, a spacious room), young people grow quite quickly. The three-month-old teenager reaches 3.5 centimeters and acquires, so to speak, a "marketable look".
At the same time, puberty occurs much later, by 8 - 9 months. It is impossible to catch this moment in the daily behavior of fish, since the males do not show their sympathies in any way. However, the attentive observer will notice that the females begin to take shape.
Green neon is a typically soft haracinide. It is unpretentious at the usual time, during the breeding season, it becomes more demanding for hydrochemistry: a positive result can be achieved with dGH 0.2 - 1.0 degrees, dKH 0.05 - 0.10 degrees and pH 6 - 7. With an increase in the degree of mineralization of water The survival rate of the larvae decreases. Especially detrimental is the excess of carbonate salts on them.
The preparation of water in my farm is as follows. Desalted in ion-exchange columns, water with dGH 0.2 degrees, I pour into the pure spawning. As the water from the columns goes not only demineralized, but also degassed, for one or two days I turn on an intensive purge to establish its normal gas composition. Then, without turning off the purge, I adjust the pH with the help of ten percent solutions of orthophosphoric acid and sodium alkali and place a bush of a plant (more often - the Thai fern of Microsorium pteropus). After a day I re-adjust the pH, and the next evening you can plant fish. No necessary, in the opinion of many authors, additives of decoctions of peat, alder cones, etc. not required.
Favorable for breeding is a temperature of 25 to 26 degrees C. Fish are usually spawned in a day or night, but sometimes for one reason or another there are delays of another 2 to 3 days. If you wish, you can observe the marriage games. To do this, you will have to be patient and put out the light in the room, leaving a weak light away from the aquarium, allowing you to barely see the fish. A revival in the spawner will tell you that things have gone smoothly.
If you have the opportunity to check early in the morning whether spawning took place, then the separator grid at the bottom is not necessary - at night, fish will not be looking for caviar.
Often in the aquarium literature, one can find references to the fact that it is difficult to pick up a good pair of producers from green neon and it is mainly the "untenable" males who blame it. I would not venture to speak so categorically. My long-term observations of these fish really revealed some vague tendency to passivity in the males of Hemigrammus hyanuary. Nevertheless, I can not formalize this in a clear pattern.
In conclusion, I want to note that this once widespread fish is now very rare. And it's a pity, because the relatively low-key appearance of green neon is completely compensated by their unpretentiousness and amusing behavior, especially if not two or three fish swim in a water basin, but a gay flock of 10-15 fishes that looks great in a decorative aquarium. Not without reason in Europe the interest in these fish has been preserved for half a century.


I. Vanyushin, Moscow Aquarium No. 4, 1999.