represented in caves. Includes saprophytes, pathogens and chemoautotrophs (which live by oxidizing or reducing iron and sulphur compounds). Bacteria are at the base of many cave food-chains.
Phylum Cyanobacteria
Some species are capable of synthesizing their pigments in the absence of light. Various Chroococcaceae are implemented in the formation of complex cave mineral deposits such as moon milk and tufa (see glossary).
Kingdom PROTISTA
Phyla Phytoflagellata, Zooflagellata, Sarcodina, Ciliophora, Sporozoa
Protista are often abundant in interstitial waters and many species occur in caves. In Turkmenistan, brackish wells in the Kara-Kum desert contain abundant populations of at least 10 species of unusually tiny, thin-shelled Foraminifera. Cave clays often contain Mastigophora, Sarcodina, Amoebina and some Ciliata.
Kingdom PLANTAE
Phylum Chlorophyta
Various free-living algae, such as Chlorella, Scenedesmus and Pleurococcus are found growing deep inside caves. Though able to synthesize pigments in the dark, they appear to use non-photosynthetic metabolic pathways. The other plant phyla Rhodophyta, Phaeophyta, Bryophyta are essentially absent from the dark parts of caves. The phylum Tracheophyta is represented by a very few aberrant saprophytic species which can live independently of sunlight.
Kingdom FUNGI
Phyla Zygomycetes, Ascomycetes, Basidiomycetes, Myxomycetes
Fungi are important in cave ecosystems. Most are saprophytic on organic material washed into caves and form the main food base of cave communities. Some are epizoic (live on the outer surface of animals) or parasitic. Most members of the phylum Oomycetes are parasitic on flowering plants and therefore not represented in caves.
Kingdom ANIMALIA
Phylum Porifera
Encrusting sponges may be the commonest organisms in tidally flushed submarine caves.
Phylum Coelenterata
Hydra viridissima occurs in groundwaters in the Southern Carpathians of Europe. Marine Hydrozoa and Anthozoa are commonly found in submarine caves.
Phylum Platyhelminthes
Rhabdocoel Turbellaria are common in wells, springs and groundwaters. Cave-evolved Triclads have a worldwide distribution, with most species within three planarian families: Dendrocoelidae, Kenkiidae and Planariidae.
Phylum Nematoda
Free-living nematodes are frequent in groundwaters, caves and mines worldwide. Several freshwater species of the otherwise exclusively marine Desmoscolecidae inhabit caves in Slovenia.
Phyla Nemertinea and Rotifera
A few species of these small creatures inhabit interstitial waters and caves.
Phylum Annelida
Submarine caves often contain huge populations of sedentary polychaete worms and a number of cave-evolved freshwater polychaetes are known from Switzerland, Slovenia, Japan and Papua New Guinea. Oligochaete worms are often abundant in caves, in groundwaters and sediments. The family Lumbriculidae contains many essentially cavernicolous species. Cavernicolous leeches are known from Central Europe and several tropical countries.
Phylum Mollusca
There are many cavernicolous Gastropoda within the families Auriculidae, Zonitidae, Subulinidae, Enidae and Valloniidae (terrestrial species), and Hydrobiidae (aquatic species). The Bivalvia include cavernicolous species of Pisidium and Congeria in Europe and Japan.
Phylum Onychophora
The South African species Peripatopsis alba is known only from caves.
Phylum Arthropoda
Subphylum Crustacea
Class Remipedia: Recently discovered in submarine caves in the Bahamas and Canary Islands, these actively swimming predators resemble aquatic centipedes.
Class Ostracoda: There are many groundwater species, some of which also occur in larger caves.
Class Copepoda: Many cyclopoids and harpacticoids occur in caves and interstitial groundwaters worldwide.
Class Malacostraca: The monospecific order Spelaeogriphacea is so far known only from caves in South Africa. Thermosbaenacea and Mysidacea are widespread in submarine caves and brackish groundwaters and a few species have made the evolutionary shift into freshwater caves. Isopoda are one of the best-represented orders in the subterranean world, with hundreds of cavernicoles described within the Asellidae and Oniscoidea. The Amphipoda, notably the Gammaridae, are equally well represented. Cavernicolous decapods such as crayfishes, galatheids, crabs and river prawns are particularly widespread in the tropics. Groundwater-inhabiting members of this class often belong to ancient lineages and the distributions of related taxa provide important evidence in reconstructing the history of the planet.
Subphylum Uniramia
Class Diplopoda and Pauropoda: Worldwide there are hundreds of species of cavernicolous millipedes, and particularly of Polydesmoidea. They often show relictual distributions which mirror past configurations of the earth’s crustal plates, long since redistributed by seafloor spreading and continental drift. A few Pauropoda are known from caves.
Classes Chilopoda and Symphyla: Cavernicolous Scolopendromorphs and Lithobiomorphs are known from European caves. In the tropics there are also cave-evolved Scutigerids. The Symphyla live in the soil and look like cave animals, but most feed on living plant roots and so are excluded from deep cave habitats.
Class Insecta: The Collembola and Diplura are primitive, wingless, ground-dwelling insects which require a high humidity. They include a large number of cave-evolved species worldwide. Cavernicolous Blattodea are mostly confined to the tropics. Within the Orthoptera, the Rhaphidophoridae or camel crickets contain a number of conspicuous cavernicoles with a worldwide distribution and a few cavernicolous gryllids are found in the tropics. There are cave-evolved Dermaptera, Psocoptera, Hemiptera, Trichoptera, Lepidoptera and Diptera. Not surprisingly, the majority of cavernicolous insects belong to the largest order and the most successful group of animals on earth, the beetles (Coleoptera). At least 22 families contain cavernicoles, which reach their greatest diversity and specialization in the Trechidae and Leiodidae.
Subphylum Chelicerata
Class Arachnida: A few cavernicolous Scorpiones, Uropygi, Amblypygi, Schizomida, Ricinulei and Palpigradi are known from tropical regions. Pseudoscorpions are well represented in caves, with over 300 cavernicolous species, many of which are giants among their kind, with very long legs and claws. The Opiliones
