A strikingly beautiful Nannostomus species from Peru, known in the trade under the names Nannostomus marginatus „Purple“ or N. marginatus „Red“ for some time already, has now been described scientifically by Axel Zarske from Senckenberg Naturhistorische Sammlungen Dresden, Museum für Tierkunde as Nannostomus rubrocaudatus. The type specimens originated from Peru and were imported by our company.
At the first glimpse the species reminds one on the popular N. mortenthaleri, but a closer look shows clear differences. For example, in N. mortenthaleri the belly is always white, in N. rubrocaudatus never.
Both species have a well developed sexual dimorphism and dichromatism. Although only the males show red colours over the whole body, the intensity of this coloration depends much on the mood of the fish. However, the females´ ventral fins have a different shape from the males´ ones, so it is always possible to distunguish the sexes.
The maximum length of N. rubrocaudatus is 3 – 3.5 cm, but they should not be kept in small aquaria. The males fight quite fiercly and without enough space for the looser to flee there might occur even injuries. Otherwise the keeping of the fish is complication free.
The natural distribution is in Peru, Prov. Loreto. Here the fish is collected commercially in the small village Saramirisa at the banks of the Maranon (the upper Amazon river) between the rivers Morona and Santiago. The fish live beween twigs and can be collected only piece by piece, thus the realtive high price in the trade. Mass-collecting like in many other species of Nannostomus, where thousands of specimens can be cought with only one netting, are not possible in N. rubrocaudatus and N. mortenthaleri.
The scientific paper can be downloaded for free under http://globiz.sachsen.de/snsd/publikationen/vertebrate-zoology/vz59-1/02_Vertebrate_Zoology_59-1_Zarske.pdf
For our customers: Nannostomus mortenthaleri has code 272256, N. rubrocaudatus 272264 on our stocklist.Please note that we exclusively supply the wholesale market.
Text: Frank Schäfer, photos: Frank Schäfer and Erwin Schraml/Aqualog archieves
