Rivulus romeri, Costa 2003


Alternative name Laimosemion romeri.

The species Rivulus romeri is named after Uwe Römer, a German aquarist and writer of several manuscripts and books about fishes.

It is a dwarf species that is most likely related to Rivulus tessellatus (Huber 1992).

The species was collected by Uwe Romer, in a brook that is tributary to Igarape Iauiri which is a tributary of Uaupés River that than tributes the Rio Negro. (In Colombia the same river is named Rio Vaupes.) He discovered this small species on Februari 21, 1995.


Laimosemion (Rivulus) romeri - male. Igarape Iauiari. Image made by F. Vermeulen.
Laimosemion (Rivulus) romeri - female. Igarape Iauiari. Image made by F. Vermeulen.


Keeping and breeding is easy but 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 5 to 15 eggs.

The eggs should be collected by hand and stored for about 14 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 prevent fungus coming up.


After hatching the newborn fry can eat fresh artemia nauplii without any problem but it is better to feed them infusorien in the first weeks also or place a dense layer of floating plants on top of the water. It takes 5 to 6 months to raise them to maturity.

There lifespan can be up to 2,5 years in captivity.

Remarks :


Laimosemion (Rivulus) romeri - male. Igarape Iauiari. Image made by F. Vermeulen.
Laimosemion (Rivulus) romeri - female. Image donated and made by S. Sladkowski.
Laimosemion (Rivulus) romeri - male. Image donated and made by S. Sladkowski.



Max. size: SL 3.0 cm.
Dorsal 7.5,
Anal 9.5,
D/A 7.0,
LL scale count (average)29.5
Pre- dorsal length to % SL – 73.8 %
Depth to % SL – 29.0 %


Costa, W.J.E.M. 2003. A new miniature rivuline fish from the upper Negro River basin, Northern Brasil (Teleostei, Cprinodontiformes, Rivulidae). Arquivos do Museu Nacional, Rio de Janeiro, 61 (3): 176, figs. 1-3.