Hemigrammus rhodostomus – Rummy-nose tetra (Hemigrammus rhodostomus)

This is the 'real' rummy-nose. The species most often sold as such is, in fact, the firehead tetra, H. bleheri. These 2 are very similar in appearance, as is the 'false' rummy-nose, Petitella georgiae. The 3 species can distinguished by several factors.

The first, is by the extent to which the red colouration on the head of the fish extends into the body. H. bleheri is the only one of the 3 in which the red extends beyond the gill covers. The amount of red colouration on …