Tissue C:N:P stoichiometry of Corbicula fluminea and Bellamya aeruginosa was examined.

Tissue stoichiometry exhibited substantial natural intraspecific variation.

Tissue %P presented the greatest variations, followed by %N content, and lowest in %C.

Tissue %P and %N increased with increasing lakes trophic levels.

The two molluscs can adjust tissue stoichiometry in relation to nutrient enrichment.