a) Pearl roach/Redeye (Leuciscus erythrophthalmus)
b) Souffia (Leuciscus aphya)
Coloured engraving, by Carl Wilhelm Hahn (1786–1835)

Hahn's engraving features two fish species, each classified within their respective taxonomic groups according to the understanding of his time: the Pearl Roach or Redeye, common names for the rudd (today Scardinius erythrophthalmus), a freshwater fish found across Europe and parts of Asia that has a distinctive red or reddish-orange iris, and the Souffia (today Telestes souffia), a small freshwater fish in the cyprinid family, native to central and Southern Europe, particularly in rivers and streams with clean, well-oxygenated water.