Alternative name Anablepsoides urophthalmus.

The history of Rivulus urophthalmus is very long. It was discovered in 1851 by Mr. Stevens and described 15 years later by A. Gunther as Rivulus urophthalmus. The type locality is Belem in the Brasilian state Para. No further details were provided.

The name was given in reference to the supra caudal ocellus (spot) of the female (and in young males to) and at that time this feature was not known by many fish species. In the moment we know that most Anablepsoides females have this ocellus.

There are also, spread over an immense part of the South American continent species that look very similar to this species. It seems that Rivulus urophthalmus has a large area occupated but on the other hand it is clear that many so called R. urophthalmus can belong to other, close related, taxa. The whole assemblage of species was called the Rivulus urophthalmus spiecies group but Costa (2006) renamed the species group into Rivulus micropus species-group and now included them into the genus Anablepsoides a move that is discussed by Huber (2012) and other scientists.

To that group are also counted: R. bahianus, R. caurae, B.christinae, B.corpulentus, B.cryptocallus, B.deltaphilus, B.elongatus, B.erberi, B.intermittens, B.iridescens, B.lanceolatus, B.limoncochae, B.lungi, B.mazaruni, B.micropus, B.ophiomimus, B.peruanus, B.rubrolineatus, R. stagnatus, B.taeniatus, R. urophthalmus, B.waimacui and B.xanthonotus.

The species on the images above are collected not to far from the city of Belem, also not far from the terra typica of the original B.urophthalmus. At the time of description it was not common to specify the exact spot the species was collected, sometimes a nearby city or even a huge riversystem was given as terra typica. This makes it very hard nowadays to find the original location to compare new material with the types in the museum and investigate other data.

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 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 years in captivity.

Remarks :

Max. size 7.0 cm.
Dorsal 7.0,
Anal 12.0,
D/A 10.1
LL scale count (average)39.0
Pre- dorsal length to % SL – 78.0 %
Depth to % SL – 19.0 %