dbRDA ordination of the assemblages structure of caves on the species (A) and families (B) levels, as well as ordination of species (C) and families (D) preferences (based on Bray–Curtis similarity index) factored with illuminance ranges: light–fully illuminated (surface), twilight–half-light (ecotone), dark–darkness (subterranean). Abbreviations: DIST–location of cave, TEMP–temperature of water, MIN–total mineralization (ppm), PH–acidity; families names: Dug.–Dugesiidae, Dend.–Dendrocoelidae, Naid.–Naididae, Lumb.–Lumbriculidae, Erp.–Erpobdellidae, Hydrob.–Hydrobiidae, Lymn.–Lymnaeidae, Ell.–Ellobiidae, Phys.–Physidae, Plan.– Planorbidae, Sphae.–Sphaeriidae, Trich.–Trichoniscidae, Gam.–Gammaridae, Niph. –Niphargidae, Crang.–Crangonyctidae, Typhl.–Typhlogammaridae, Aty.–Atyidae, Aesh.–Aeshnidae, Hept.–Heptageniidae, Baet.–Baetidae, Lept.–Leptophlebiidae, Nem.–Nemouridae, Leuc.–Leuctridae, Perl.–Perlodidae, Elm.–Elmidae, Hyd. –Hydrophilidae, Hydr.–Hydraenidae, Scir.–Scirtidae, Psych.–Psychomyiidae, Phil.–Philopotamidae, Hydro.–Hydropsychidae, Polyc.–Polycentropodidae, Glos.–Glossosomatidae, Rhyac.–Rhyacophilidae, Limn.–Limnephilidae, Lepid.–Lepidostomatidae, Seric.–Sericostomatidae, Goer.–Goeridae, Ber.–Beraeidae, Uen.–Uenoidae, Limon.–Limoniidae, Chir.–Chironomidae, Cerat.–Ceratopogonidae, Sim.–Simulidae, Psycho.–Psychodidae, Dix.–Dixidae, Strat.–Stratiomyidae. The abbreviations of species names are presented in Suppl. material 1: table S4. Numbers refer to cave numbers in Table 1.