Represented in life-size (1.05 m), the Fish Engraving is engraved and sculpted in bas-relief on the ceiling of the vault, enhanced with red color. It is a quarter-billed salmon, with an upturned jaw, whose attitude is characteristic of the male exhausted by spawning. The theme is rare since only around ten fish have been recorded in Paleolithic cave art.

Very numerous in prehistoric portable art known throughout the world, fish figures represent only 1% of the bestiary of cave art – including barely sketched or just “pisciform” figures. Around ten representations of salmonids are known (Abri du Poisson, Grotte du Portel in Ariège, two at Ekain in the Spanish Basque country, including the probable trout of Niaux).

Other cave works have since been identified by Christian Archambeau and Alain Roussot, notably a black negative hand and incomplete engraved animal figures.