The genus Moema was erected by Dr. Wilson Costa in 1989 and belongs to the assemblage whith Pterolebias, Renova and Trigonectes in it. It is closely related to the genus Neofundulus.

Scientists are doubtful if Moema must be seen as an subspecies of Trigonectes or even has to be synonimized with that.

Fact is that these fishes become all very large, have an elongated body that resembles to Rivulus and have tails that become rather wide as an flag.

The genus belongs to the typical group of annual fishes and keeping and breeding is in general not easy for beginning aquarists. In the first place the species grow to an large size and need a lot of life food daily, to reach maturity. They can get 12 to 18 cm in length and this in 8 to 10 weeks time. For this species a small tank will not do. During there juvenile stage they eat the smaller brothers and sisters as soon as they can swallow them, even if food is plenty. To avoid this you need to separate the bigger youngsters very early all the time. Adult males will often fight each other also.

Moema are found over a wide range. Almost all of the members live at the upper part of rivers that flow into the Amazon. Only the Moema of Guyana (M. aff. staecki) and Venezuela (M. portugali) do not live in tributaries of the Amazon. There however they occur in rivers that are connected during extreme rainy seasons to the tributaries of the Amazone River.

In Guyana for example there is the Takatu river, tributary of the Rio Branco, part of the Amazone Drainage. The Takatu River flows along the Rupununi Savannah and forms the border between Guyana and Brasil. It happens sometimes that the Rupununi Savannah completely inundates and provide an connection between Takatu- and upper Rupununi River. This Rupununi river tributes the Essequibo river that flows to the North. This also occurs between the upper Rio Negro and the upper Orinoco in Venezuela.

During these periods species can migrate from one system into the other.

Behaviour:

Often females, that grow a little bit slower, will be eaten by the faster growing males. If the fishes make it to adulthood, breeding is not difficult and there productivity is rather high. Keep one male with at least 2 or more females in a tank from 50 ltr's or more and supply places for cover. For spawning, the trio need a high spawning- container with closed lid on top and an entrance- hole at the side. Just like an bird nesting house. Doing so, most of the peat moss will stay inside. If noting covers the upper opening however the peat will completely get propellered out of the container after a few dives already.

Eggs need 6 to 10 months to develop. Average storage temperature about 26 to 28 C.