Recently we obtained a shipment of piranhas from Peru. The fish are 5-9 cm long. At the first glimpse the shipment could be told apart into two phenotypes. First, there were fish with comparatively small spots, a lot of red coloration in the anal fin and a comparatively thin black border on the caudal fin. The second form has comparatively large spots, almost no red in the anal fin – this fin also has a more distinct black seam – and a very broad black seam on the border of the caudal fin. However, „technically“ speaking both forms do not differ in any aspect that can be seen with the bare eye, like body shape etc.
The fish with the small spots fits very good to the piranhas we often obtain from Peru and which we have determined as Serrasalmus compressus in the past. The other animals belong for sure to the same closer relationship within Serrasalmus, but there is no scientifically accepted other species than S. compressus that fits. The only possible exception may be the Black Piranha (S. rhombeus), which we get from Peru from time to time (see https://www.aquariumglaser.de/en/fish-archives/gigantic_black_piranha_arrived__en/). However, Serrasalmus rhombeus is easily distinguished from other piranhas by the red eye, that should already be visible in 5-9 cm long animals (see https://www.aquariumglaser.de/en/fish-archives/piranhas_serrasalmus_niger_en/). As we could find no matching name for the second phenotype we now offer them all under the name of S. compressus, but we cannot exclude the possibility that two species are involved, maybe even a scientifically undescribed one.
For our customers: the fish have code 291332 on our stocklist. Please note that we exclusively supply the wholesale trade.
Text & photos: Frank Schäfer