Цитирую:
"The subterranean catfish Phreatobius cisternarum is one of the most puzzling catfishes. Its unusual subterranean environment, bright red coloration, aberrant morphology, rarity in collections and uncertain phylogenetic relationships, all make the species an intriguing member of the Siluriformes. Described by Goeldi (1905), P. cisternarum remains the only species in its genus, although other, yet undescribed, species are currently known to exist. It inhabits exclusively the subterranean waters underlying the mouth of the Amazon. Specimens of the species have been collected on areas both north and south of the river mouth, as well as on the huge island in between (Marajó Island)."