Capillaria is a genus of nematodes in the family Capillariidae (or Trichinellidae, according to some classifications). The taxonomy of the Capillariidae is disputed, with species included within either the single genus Capillaria or 22 different genera (Amphibiocapillaria, Aonchotheca, Baruscapillaria, Calodium, Capillaria, Capillostrongyloides, Crocodylocapillaria, Echinocoleus, Eucoleus, Freitascapillaria, Gessyella, Liniscus, Paracapillaria, Paracapillaroides, Pearsonema, Paratrichosoma, Pseudocapillaria, Piscicapillaria, Pseudocapillaroides, Pterothominx, Schulmanela, and Tenoranema). Older literature, and sometimes modern medical literature, tends to use Capillaria in the broader sense. The term capillariasis is generally used for diseases produced by all species currently or formerly classified in this genus. Some species parasitic in fish, previously classified within Capillaria, are now included in Huffmanela (family Trichosomoididae).

Species

Species in the genus Capillaria include (among hundreds of described species):