Alternative name Cynodonichthys elegans.

Rivulus elegans was discovered by Grosskopf in 1878. Steindachner described the species two years later in 1880. The type locality is near Cáceres, a small village along the Cauca River.

Since the description no discoveries of this species ever were made till I found them during a collecting trip of 3 weeks in Colombia. Garman (1895) erroneously mentionned a close relationship between Rivulus elegans and Rivulus micropus. This hypothese cannot be followed as R. micropus is a species from the mid Amazon and has higher LL counts, shorter anal fin and a more backwards position of the dorsal fin.

Dr. Jean Huber (1992) mentionned in his book "Review of Rivulus" the need of new material from the Terra Tipca and more details about the natural spreading of the species.

To find answers on the Rivulus elegans and other important issues about the Cyprinodont fishes of Colombia, the author of this site visited the northern half of this huge country and the town Cácares as well.

I was able to make a grand Tour of 26 days (februar 2008) trough the Colombian territory. I also visited Cáceres and was able to relocate the species in a small brook that was part of the Quebrada Cristalina that tribute the Rio Cauca near Cáceres.

The images at the right are the first photo's taken of life Rivulus elegans, a day after collecting. No life material of the Cáceres location could brought back as the fishes ware taken at the beginning of the tour and it turned out impossible to keep them alive during the long contignious journey that was 3 weeks of length. The collecting code for Cáceres is COL 2008-07. In 2009 I visited Colombia again and could re-collect the species at 2 different locations which one was the same as in 2008. This time I could bring them home alife.

Color- varities of the species were discovered also in a mountain creek along the road from Medellin to Bogota, part of the Magdalena drainage and near San Miguel, Caldas in the upper Rio la Miel, tributary of the Rio Magdalena as well. At this very moment (august 2010) these two species shown below are part of an investigation to see if these fishes can have a species status of there own.

They show brighter blue coulors and remarkable different pattern on the sides in males. Females of the COL 2008-12 varity do not show much differences on first sight to the Cáceres population. (see sector "variations") but show some differences in morphomeristics.

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 1.9 mm and amber colored or hyaline. 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.

There lifespan can be up to 3 years in captivity.

Remarks :

Max. size 6.5 cm.
Dorsal 9.0,
Anal 16.0,
D/A 10.1,
LL scale count (average)37.0
Pre- dorsal length to % SL – 76.0 %
Depth to % SL – 20.1 %

Steindachner., F. 1880. Zur Fishfauna des Cauca und der Flusse bei Guayaquil. Denk. Akad. Wiss. Wien, 42,: 85, pl. 6 (fig. 6.

Vermeulen, F.B.M. 2013. Four new species of Rivulus Poey, 1860, subgenus Cynodonichthys Meek, 1904 (Teleostei: Cyprinodontoformes: Rivulidae) from the Magdalena River Basin, Central Colombia, including notes on Rivulus (Cynodonichthys) elegans. Killi Data Series 2013.