This new species from São Gonçalo do Amarante, Ceará, northeastern Brazil, is described by Dr. W. Costa, Brazil originally as Rivulus cearensis.

Alternative name Rivulus (Oditichthys) caerensis.

It was found in a shallow stream within a residual humid forest inserted in the semi-arid Caatinga region. The new species seems to be closely related to R. bahianus and to the species of the R. urophthalmus group by all having the ventral surface of head entirely covered by scales and flank with horizontal rows of small reddish brown or red spots in males; it differs from all those species by possessing iris green and by the absence of the ventral process of the posttemporal bone. It is also distinguished from R. bahianus by having more robust body and a broad dark red stripe on the dorsal and ventral margins of the caudal fin in males, and from species of the R. urophthalmus group by having fewer scales in the longitudinal series and scales extending over about 40-50 % of the caudal fin.

Keeping and breeding is easy but a tight fitting cover on the aquarium is necessary because their ability to jump, even through the smallest opening, is unbelievable.

This species can, if there is enough space for them, be housed in a tank with more than one male and several females. If separated before and brought together again however, they can be very aggressive towards each other and fight to become the dominant fish. The best way to produce numbers of fry is to put a pair or a trio in a small tank of about 10 litres with a small filter in it or with some aeration. On the bottom of the tank place some peat moss or dark gravel and a floating "mop" to give space for laying their eggs. The fish will, if they are fed a rich variety of live food, spawn during their 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 coloured. It is wise to add an anti fungus to the water you store the eggs in, to prevent fungal attacks.

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 males far out number females. For some species this can become a major problem for the breeder, as he has to raise many fry to enable distribution of a few pairs to other hobbyists. Recent personal tests found that lower pH levels during the time of hatching gave a higher percentage of females. To achieve this I used some peat moss that I added to the container with the eggs just before they were ready to hatch. This peat moss also is a good way to prevent eggs from being attacked by fungus.

Their lifespan can be up to 3 years in captivity.

Remarks :

Above data are average data for most Rivuline species of this size. No data are actual available for this species so far.

Max. size 6.0 cm.
Dorsal 7-9,
Anal 12-13,
LL scale count 34.0
Pre- dorsal length to % SL – 00.0 %
Depth to % SL – 00.0 %