Alternative name Laimosemion gransabanae.

Rivulus gransabanae was described by C. Lasso, Dr. Donald Taphorn and Dr. Jaimie Thomerson.

It was found in the "Gran Sabana", a savannah landscape at high altitude of about 1000 meter above sea level, where the species can be found in small creeks and sometimes also in flooded grassland ajectant to creeks. This area is known as extremely hot and the closeby tepui's or tablemountains raise about 1.500 to 2.000 mtr above sealevel. These tepui's trigger regularly rainfall and that rainwater drains in the eastern part into rivers that belong to the upper Cuyuni and Mazaruni that are tributaries to the Essequibo in Guyana.

The Kamarang- and upper mazaruni River in Guyana is also the habitat for this species up to Imambaday were we collected the species together with the close related Laimosemion torrenticola. At the top of the Guyana shield I was able to collect a similar species in the Ekruku river near the stunning Sekaika waterfall.

The third image from the top is a Laimosemion that was collected a half hour drive from Kamoirán more to the south. This species shows different colors than the Laimosemion gransabanae as showed at the top and remind me a little to the Laimosemion torrenticola from Guyana. I call this for the time being Laimosemion aff. gransabanae THV 2010-11.

DNA sequences will be taken to find their relationship to each other.

Keeping and breeding is not 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 more or less a good number of 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. Good results are triggered when water level is low to very low and with a botom filled with leaves, some plants and a floating "mop" to give cover and space for laying their eggs. The species will, if they become a rich varity of life food, spawn during there whole adult life and produce daily between 2 to 5 eggs. The eggs are extremely large for a species so small.

The eggs should be collected by hand and stored for about 14 to 20 days in a small container. Eggs are 1.6 mm and amber colored. It is wise, to add some acryflavine to the water to provent the egss become damaged by fungus. Breeding in a permanent set-up is also possible and juveniles can grow up with their parents in the same tank.

After hatching the fry can eat fresh artemia nauplii without any problem. It takes long, between 5 and 6 months to raise them to maturity. During a recent collecting trip to the Amazonas Territories in southwestern Venezuela, and the eastern Gran Sabana area, I could recollect the species near San Rafael de Kamoirán. ( February 2010) This trip was made together with Joachim Tomas and Olivier Helker from Germany. The biotope was a small ditch with standing water, filled with slimy algea and submersable plants. At the time of our visit it was extrmely hot and dry and the dry season was exceptional long lasting over almost a full year. During the early morning around 9.00 AM we measured a water temperature of 26 Celcius. Unfortunately we were not able to take a measurement at the late afternoon but we assume the temperature must have risen far over the 30 C. than because the ditch was exposed to the baking sun during the full length of te day. No cover of any type was give shade and the waterbody was narrow and shallow. We could see the Laimosemion swimming between the plants and they were the only fish present at the biotope.

There lifespan can be up to 3 years in captivity.

Remarks :

Max. size 5.0 cm.
Dorsal 9.0,
Anal 11.0,
D/A 7.0,
LL scale count (average)32.0
Pre- dorsal length to % SL – 68.0 %
Depth to % SL – 20.1 %

Lasso, C., D.C. Taphorn & J.E. Thomerson. 1992. Rivulus gransabanae, a New Species of Killifish from Venezuela (Cyprinodontiformes, Rivulidae). Ichthyol. Explor. Freshwaters, 2,(4): 298, figs 1-3.