Trichomycterus itacarambiensis (Siluriformes: Trichomycteridae), troglobitic catfish from eastern Brazil, showing intrapopulation variation in pigmentation and eye development (Photos: Dante Fenolio). A pigmented individual, with reduced eyes and pigmentation B albino (DOPA (–) individual, with very reduced eyes, not visible externally.

  Part of: Trajano E, Carvalho MR (2017) Towards a biologically meaningful classification of subterranean organisms: a critical analysis of the Schiner-Racovitza system from a historical perspective, difficulties of its application and implications for conservation. Subterranean Biology 22: 1-26.