Nematolebias myersi
Nematolebias myersi or Myers fish (Simpsonichthys myersi) gets its name after Charles J. Simpson of California, USA, who first described it. These fish live in small river basins flowing into the coastal plains of eastern Brazil, between rio Jucuruchu, South Bahia, and rio Doce, Espírito Santo. The fish stay in shallow pools and marshes, which are replenished during the rainy season and dry up almost completely during the dry season, usually from July to November.
As reservoirs dry up, all adult fish die and their eggs undergo a diapause period until the rains come.
Males are slightly larger than females and as they mature they develop filamentous spines on the dorsal and anal fins, whereas females only develop relatively short filamentous rays on the posterior edge of the anal fin. The body of males is decorated with 10-15 dark crimson or dark brown transverse bands. The main body colour is greenish-blue or brownish-yellow. Females have pale brown body with 9-12 wide brownish-gray stripes and 1-3 black roundish spots in front part and 1-3 dark spots on lower part of tail plumage. Males reach 3.5-4 cm in length, females somewhat smaller.
It is advisable to keep Myers fish in the proportion of 1 male to 2-3 females. In this case, the aggressive disposition of the males can be greatly relieved. Suitable for keeping fish aquarium volume of 150 liters.
The ground can be anything, but the darker varieties are preferred. On the surface of the water should be placed a few bushes of floating plants. The rest of the decorations in the aquarium no requirements and can be chosen according to preference.
Water parameters: temperature 20-27° C, hardness dH 1-5°, pH 5.5-7.0. Water filtration using an external filter canister type, with a capacity per hour exceeding 4-5 volumes of the aquarium. Myers nematolebias are excellent jumpers, so the aquarium must necessarily have a cover.
The diet of the fish consists of small live and frozen foods such as daphnia, artemia and chironomid. Adult fish should not be frequently offered fatty foods and foods with high protein content. Feed the fish twice a day.
Reproduction
With the onset of the dry season, when ponds dry up, adult fish die, leaving fertilized eggs that they bury in the substrate. The eggs remain there until the rainy season begins, about 4-5 months later, at which point the fry begin to hatch from the eggs.
Fry grow very rapidly and under favourable conditions may reach sexual maturity within 3-4 weeks.
In aquarium conditions spawning stimulate the lowering of the water level in the aquarium and placing on the bottom of peat moss or coconut fibers. After spawning producers, they are transplanted into another aquarium, and the substrate is dried and placed at 2-4 months in a dark place with a temperature of 21.1-25°. After this period, the substrate is filled with water and the eggs will soon begin to hatch.
The longevity of Nematolebias myersi in aquarium conditions is about 6-16 months.
