home aquariums




Stranger Brazilian


In early 1991, I was lucky enough to visit Brazil. In Rio de Janeiro, I met with the owner of a pet store. He was extremely surprised to learn that the aquariums in Russia - a very popular activity.
I froze in silent delight in front of his aquarium. That's what I've read and seen in the photographs in the foreign editions, appeared before me in the form of a living!
But, alas, all buy impossible. Hence, it was necessary to choose. I was most interested in the fish-knives, the more I noticed kind unknown to me.
- What kind of fish? - I asked the host, but instead received the same answer another question, and this despite the fact that the knowledge of my interlocutor was never in doubt. The hand had ichthyological literature, we also did not find any information.
Thus, in addition, that the fish caught by river basin Couple in the estuary of the Amazon, and in a single copy, we did not know anything about her.
The upshot was that I just presented the fish with a wish of success in determining its species.
It looked pretty unattractive, but at the same time is unusual. The color can be described in one word: Brown. For gill covers, sides, there is a dark spot on one. Sometimes there is soft yellow horizontal stripe running from the middle of the body to the tail end of the needle.
The unusual shape of the body was the same. Medium size head, rounded in the mouth, slightly laterally compressed eel-like body, turning into a long tail shiloobrazny without fin. Anal fin extends along the body from the neck to the tail, playing the role of the engine, the pectoral fins are small and look like oars, others simply do not.
Two months fish lived on the boat, crossed the Atlantic and arrived safely in St. Petersburg. There, she settled in the aquarium with Apteronotus albifrons.
At home, I identified her views on the benefits available to the me. It was a representative of the suborder Gimnotovidnye (Gymnotoidei) - Sternopygus macrurus (Bloch - Schneider, 1801). However, information about the habits and habitats in nature were scanty.
S.macrurus widespread in tropical rivers of South America. Fish quite a large 50 - 60 cm. It grows to such a size and in captivity. My Brazilian guests (it was a female) in a 500-liter tank for four and a half year rose to 50 centimeters (on arrival and its length was 22 cm).
Apparently, when the content of the water parameters sternopigusov special values ​​have not, you just need to avoid extremes. The optimum temperature 24 - 26 degrees C, although it can vary from 22 to 30 degrees C. The fish feed on all kinds of worms, small crustaceans and larvae of aquatic insects. Perhaps eat and small fish, but I did not watch.
S.macrurus leads primarily nocturnal. During the day hiding in various shelters, appropriate to its size. This must be taken into account in the design of the tank, which should be large thickets of aquatic plants, driftwood, ceramic pots and pipes, piles of rocks with caves.
It should be remembered that sternopigus - territorial views, guarding your "house". Should other fish closer to the busy shelter, as immediately the owner makes a warning shot, driving out the intruder. However, special aggressiveness he showed no to his fellow or other fish. In one of my aquariums 22 - 25-centimeter sternopigusy coexist with six fish species, inferior to them in size. Like most members of the suborder Gymnotoidei, they have the bodies of weakly electric orientation.
For a long time my sternopigus was in an aquarium in the singular. It was only in June 1994, 12 copies S.macrurus been received from the German aquarium company. However, they are more like a mummy than living beings. Said all the "charm" of transportation and temporary detention. The length of the fish ranged from 13 to 22 centimeters, which was not comparable to the size available to the individual me.
After a month of quarantine and abundant feeding Novoselov found normal. Without loss. Fish grew quite quickly, willingly, but without greed eating live and frozen bloodworms, Tubifex, koretra.
After 2.5 - 3 months it became possible to determine the sex of my pets. Abdomen of females noticeably rounded, males also remained slim. Perhaps there are other signs of sexual dimorphism, but I was able to observe them not.
In a 400-liter aquarium which contained 4 females and 3 males, several kinds of substrate were made, from which (or in which (presumably could be spawned eggs water temperature maintained at 25 -. 26 degrees C, hardness 6 - 7 degrees, pH 6.5 - 7. twice a week, replacing water (20 - 25%) at the latest, to defend.
The first spawning occurred in the night from 23 to 24 January 1995. He proceeded unusually, is not the case, as in Apteronomus albifrons and Hypopomus sp.
Caviar has been delayed by a large flat stone, not lying ruins of large ceramic tubes. This "structure" formed a relatively large, tapered at the edges of the niche corresponding to the size of the fish (25 - 29 cm). Large eggs (diameter 3.5 - 4 mm) correct spherical, translucent, light gray slide housed in the shelter, reminding laying Ancistrus dolichopterus. The next morning, I found another pipe laying under the debris just beyond the first. And with the fish inspection and found two females spawned.
Although neither the participants spawning or their neighbors did not show a calf gastronomic interest, I still suffered it in another container with the same water parameters. One was laying about 1,200 eggs in the other - more than 1500, and in spawning was not involved older, the largest female.
The first larvae appeared in about 70 hours. Light gray "worms" with huge yolk sac and relatively small head, belted from the base of the skull to the neck for the whole body perimeter of a fin were similar to the larvae of other representatives Gymnotoidei. Unfortunately, part of the unfertilized eggs appeared, and some died from contact with tainted. The number of larvae was first clutch 520, 430 from the second.
Next spawning followed until mid-April, at intervals of 3 - 4 weeks. The eggs I found in shelters, formed by stones and fragments of pipes. Sometimes she stayed there before the larvae, which adults do not touch. One of the nests was very convenient for observing a narrow "corridor" between the two pipes. Again surprise. A male standing near the masonry and movements of anal and oral direct the flow of water to spawn. As soon as someone from relatives appear nearby, the male immediately vigorously persecuted not application reviews and returned to the masonry.
The percentage of larvae exit from the protected eggs was much higher. Juveniles spread across the aquarium, hiding in shelters, and that the parent caring for the offspring stopped.
I was able to observe the spawning S.macrurus and daytime in dim lighting. Spawning fish came to the shelter and got into his sides clinging to each other. At this point, the female is ejected from the anus, which is located under the throat, between the gill covers, a small portion of adhesive eggs, and immediately came out of their hiding places. The male followed her. After a few minutes everything was repeated. Spawning lasted for 4 hours.
The length of the larvae were born 9 - 10 mm. During the first 12 - 14 days they exist at the expense of the content of the yolk sac, not paying attention to the food. As a starter feed I used nauplii Cyclops or Artemia, willingly eats fry. Part of the water in the rearing tank replaced regularly.
Two weeks later, the length of the fry was 15 - 17 millimeters. They completely absent dorsal fin, tail has been a needle. By the end of the third week of teenagers could feed Tubifex and small incised a crank. In months of age juveniles, aged 25 - 30 millimeters, took the form of adult fish was transplanted into the aquarium larger volume. With abundant feeding young sternopigusy quickly grew to six months and some individuals reaching 20 - 22 centimeters.
Comparing the size of the manufacturer at the time of spawning and adolescents suggests that sexually S.macrurus are 12 - 18 months.


J. Usenko of Sank Petersburg Aquarium № 3, 1996