Alternative name Laimosemion rectocaudatus.

It was Patrick de Rham from Lausanne, Swiss, that discovered the species September 19, 1979 in Northern Peru near Iquitos.

This species did belong to the subgenus Laimosemion erected by Huber. Costa (2006) placed the species into a new erected subgenus named Owiyeye but in 2011 transferred all Laimosemion inclusive Owiyeye into the genus Laimosemion by upgrading the subgenus Laimosemion to genus.

The species is part of a species group with following components: Laimosemion altivelis. L. amanapira, L. rectocaudatus and L. tecminae and a new species to science from a pace called Selva de Tobogán near puerto Ayacucho. (Description in progress.) Laimosemion rectocaudatus has, other than its clade-members, no extended ventral fins. Laimosemion rectocaudatus and L. tecminae are strongly related following the results of molecular biology.

The fish can be found in their habitat with other killifishes. So are there Anablepsoides atratus, Anablepsoides rubrolineatus, Anablepsoides iridescens and Anablepsoides elongatus. Not so often, occasionally also, it lives sympatric with Anablepsoides intermittens and Aphyolebias peruensis.

Keeping and breeding is not to easy and a good cover of the aquarium is necessary because there ability to jump, even true the smallest opening, is unbelievable.

This species can, if there is enough space for them, housed in a tank with more males than one only and several females. If separated before and brought together again however, they can be very agressive to each other and fight to become dominant to others. The best way to have much offspring is to put a pair or an trio in a small tank from 10 liters with a small filter in it or with some airation. On the bottom some peat moss or dark gravel and a floating "mop" to give space for laying there eggs. The fish will, if they become a rich varity of life food, spawn during there whole adult life and produce daily between 3 to 6 eggs.

The eggs should be collected by hand and stored for about 16 days in a small container. Eggs are 1.6 mm and amber colored. It is wise, to add to the water you store the eggs in, some acryflavine to provent fungus coming up.

After hatching the young fry can eat fresh artemia nauplii without any problem. It takes 4 to 5 months to raise them to maturity. Often the number of males is far above the number of females. For some species this can become a major problem for the breeder as he has to raise many young fishes and so become able to distribute a few pairs to other hobbyists. Recent personal tests laerned that lower pH levels during the time of hatching gave a higher percentage of females. To achieve this I use some peat moss that I add to the container with the egss just before they are ready to hatch. This peat moss also is a good way to prevent eggs to become attact by fungusses.

There lifespan can be up to 3,5 years in captivity.

Remarks :

Rivulus rectocaudatus is not a easy breeder if the keeper is not expirienced. It takes a longer time to raise this species to adulthood. Egg production is relatively low in my expirience.

Max. size 6.0 cm.
Dorsal 8.0,
Anal 14.0,
D/A 11.0,
LL scale count (average)37.0
Pre- dorsal length to % SL – 74.0 %
Depth to % SL – 18.0 %