Nannostomus marginatus is widely known among amateurs in aquarium circles. The popularity of this interesting fish can be compared with some haracin, for example, tetra von Rio, minor or neon.
From the first days of maintenance in aquariums, the nanostomus marginatus won the sympathies of aquarists. The reason lies in the attractive color, calm nature and ease of breeding.
In nature, this fish lives in the rivers of Suriname, the Amazon Basin and Guyana. About a dozen species of fish enter the genus Nannostomus, of which half were found in domestic aquariums. All fish have common features of behavior, body shape and color.
The body of the nanostomusa is slender and elongated, the mouth is small, and large eyes are located above. The body color is dominated by longitudinal strips, the number of which can vary from one to three.
The fins of many nanostomus species are colored red.
Nannostomus marginatus is considered one of the brightest and most beautiful representatives of its kind. The fish deserved its popularity due to its contrasting color and elegant appearance. A pair of clear stripes running from the base of the tail to the head are divided among themselves by a brilliant golden stripe, in the middle of which there is a red area.
Another not so bright and short strip runs along the abdomen. Just below there is another thin dark strip that originates from the base of the anal fin and ends at the lower jaw.
In some cases, the third strip is weakly visible in males and it is short, and in the most rare cases it may be completely absent. But in no way can such a sign be considered as a proven one for determining the sex of a fish, because for some females the third strip may be poorly visible.
At the same time, this strip may be pronounced in some males.
Unpaired fins, except for the tail, are painted red with a thin black edging. Pectoral fins are transparent in appearance, abdominal – have a reddish tint. The tail has a gray outflow, the blades are rounded with a weak neckline.
Adipose fin, so what is missing. Males are smaller in size than females, the belly is tucked up, the fin is pointed.
Anal fin in females of angular shape, the tip of which is absolutely transparent and can be seen only if you carefully examine the fish.
It’s funny to watch the color of marginatus at night. In some species of nanostomus, the coloring can have many differences with the usual daily variation, which can provoke surprise from an inexperienced lover.
However, Marginatus this feature applies only partially. At night, the stripes at marginatus turn pale, and the central strip turns from continuous to intermittent.
Fascinating is the fact that the female is happy to show night coloring in the daytime.
Active mating of the male becomes a provocateur of such a demonstration, while the female is not yet ready to spawn. In some sources, the maximum size of the marginatus nanostomus does not exceed 4 centimeters, but this is not entirely true, because the size of the fish depends on the conditions in which they are contained and feeding.
Nannostomus marginatus is a schooling fish that prefers to stay near the upper layers of the reservoir. In search of food, fish can move around the entire aquarium, and in the process of hunting, they periodically get together, as if checking that none of the flock has been pulling out. It’s funny to watch the rivalry of males, who spread their fins and quickly tremble like hummingbirds with their wings.
During periods of spawning, the most impatient males actively pursue females through the aquarium, but the case never reaches wrecking.
The parameters of the content of nanostomusov in the aquarium:
- Overall hardness from 8 to 17 degrees;
- Active reaction environment 5.8 – 7.2 pH;
- Old peat water temperature 24 – 26 degrees.
Water parameters for reproduction:
- The total water hardness is 1.5 – 2.5 degrees;
- Carbonate – 0;
- Active reaction environment 5.0 – 6.8 pH;
- The water temperature is 26 – 28 degrees.
There were attempts to keep the nanostomus marginatus in harder water (about 20 degrees), and these attempts ended without any disastrous consequences. Despite the fact that the nanostomus lives in soft Amazonian water, this fish is able to survive in very hard water while being kept in an aquarium without any damage.
But, if you plan to breed this fish, the water should be soft. And this is not a whim of producers who successfully spawn in the general aquarium.
Soft water needs a calf for normal development.
I would like to separately dwell on the volumes of the spawning aquarium. In some aquarium sources it is written that the volume should be from 3 liters.
You will say that a spawning capacity of 3 – 5 liters is good, but not quite. It turns out that the smaller the volume of the aquarium in which the spawning took place, the smaller the number of eggs will survive.
The fact is that after spawning, producers like wolves scour the aquarium and eat their own eggs.
The first half an hour after spawning, a sticky egg that remained in front of the parents will be eaten. Add to this the weak fecundity of nannathomus females and the rather long spawning period, which can last several days.
In the end, you get about 10 – 15 percent of the whole caviar.
If you believe experienced fish farmers, then the females of nannostomus are able to bring in a few days of spawning about 100 eggs, from which little remains. Aquarists have tried many tricks to save as much caviar as possible: they spawn in large aquariums with dense vegetation with small leaves; they put fish to spawn in special spawners, which are divided into sections, from which parents are consistently driven out; Substitute substrate with sticky caviar for a new every half hour and other things.
But, unfortunately, a reliable way to protect caviar has not yet been invented. The maximum that you can get from an adult couple is three dozen fry, and if there are about 50, then consider yourself lucky.
As soon as the female spawns, she immediately turns to her and eats with appetite. Similar behavior was observed for males.
If these fish behaved in this way in nature, then nanostomuses would hardly have survived to this day.
Unfortunately, there is no information in domestic and foreign aquarium sources as to why fish behave this way towards caviar. As a rule, only the facts of persistent eating of their future offspring. There is a hypothesis that when kept in aquariums during spawning, fish do not receive adequate nutrition, as a result, they eat their eggs, compensating for the lack of some important element.
However, this is only a hypothesis.
With proper care and high-quality balanced feeding, young nanostomus grows very quickly: by the fifth week of life, their length can be 1.5 centimeters, by the seventh week 17-18 centimeters and at two months of age 2.5 centimeters. At the age of three months, fish already show signs of sexual dimorphism.
The females are slightly larger than the males, and in the latter the anal fin has a rounded shape. In their behavior, young animals are no different from adult individuals.
Raising fry should not cause any problems for the aquarist. Starter feed is the well-known “live dust”.
The larvae from the first days of inactive, respectively, the feed in the aquarium should be in excess. The larvae feed during the day, but in small portions.
After 4 days, you can add artemia to the diet of nauplia.
At the same time, it is recommended to put a couple of snails ampoules or ancistrus into the aquarium so that they can dispose of the remnants of the food that was not fully eaten. Marginatuses reach sexual maturity at the age of 6 months.
Unfortunately, the nanostomus marginatus is extremely rare in domestic aquariums, although the fish is quite interesting in terms of maintenance.