Every year is the season for a desirable fish for large show aquariums: Salminus maxillosus. And every year after the import of juveniles the question arises: are they really? Because the mostly up to 60 cm (maximum 1 m) long Salminus – they are pure predators, which feed only on other fish – imitate in color a harmless herbivore, the Brycon hilarii. Brycon hilarii also grows quite large, about 40-50 cm. In the shoal of harmless Brycon, Salminus can sneak up close to prey fish. This is called “aggressive mimicry”. So color-wise Salminus and Brycon look very similar.
The first import of such fish this season arrived last week from Colombia. They are all Brycon hilarii. Brycon hilarii is a comparatively peaceful fish, although it certainly cannot resist the “appetizer” of very small fish. But among themselves the animals are very compatible, quite different from the quarrelsome Salminus.
The correct scientific naming of our Brycon species was somewhat questionable, as a revision of the group appeared in early 2017. According to it, there are four Brycon species with a distinct black band in the caudal fin: B. orthotaenia, B. hilarii, B. whitei and B. polylepis. Of these, only B. whitei and B. polylepis occur in Colombia. Both species look completely different from our imported animals (B. whitei has a dark longitudinal band over the whole body and B. polylepis is much slimmer built than our animals). B. orthotaenia looks very similar to our fishes, but is an endemic of the Sao Francisco. Therefore, for the time being we stick with the name as Brycon hilarii (this species occurs naturally in the Amazon and Paraguay River, but is much farmed as a food fish), even though future research may show that it is a different species.
After all, in order to clarify this question, we raised a few animals years ago. In adult coloration (the photographed animals were about 16-18 cm long at that time and reached this length in 6 months, with an initial length of 4-7 cm) there is no doubt in our mind that it is B. hilairii. In addition, DoNascimiento et al. included the species Brycon hilarii in the updated checklist of freshwater fishes of Colombia published in October 2017; according to them, it occurs there in waters belonging to the drainage of the Amazon.
For our customers: the animals have code 212700 on our stocklist. Please note that we only supply wholesale.
Text & Photos: Frank Schäfer
Literature
DoNascimiento, C., E. E. Herrera-Collazos, G. A. Herrera-R., A. Ortega-Lara, F. A. Villa-Novarro, J. S. U. Oviedo & J. A. Maldonado-Ocampo (2017): Checklist of the freshwater fishes of Colombia: a Darwin Core alternative to the updating problem. ZooKeys No. 708: [1-114] 25-138
Lima, F. C. T. (2017): A revision of the cis-andean species of the genus Brycon Müller & Troschel (Characiformes: Characidae). Zootaxa 4222 (no. 1): 1-189
