''Polycladus'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

land planarian Geoplanidae is a family of flatworms known commonly as land planarians or land flatworms. These flatworms are mainly predators of other invertebrates, which they hunt, attack and capture using physical force and the adhesive and digestive proper ...

s from

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, currently comprising a single species, ''Polycladus gayi'', which occurs in the

Valdivian Forest The Valdivian temperate forests (NT0404) is an ecoregion on the west coast of southern South America, in Chile and Argentina. It is part of the Neotropical realm. The forests are named after the city of Valdivia. The Valdivian temperate rainfores ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

Description

''Polycladus'' is a very understudied genus of land planarians. It was defined as land planarians with a wide, flat and leaf-like body, having the entire ventral surface ciliated and with mouth and gonopore posteriorly shifted in relation to other land planarians. The copulatory apparatus has a well-developed permanent penis and the female canal enters the genital antrum ventrally.Ogren, R. E. and Kawakatsu, M. (1990). ''Index to the species of the family Geoplanidae (Turbellaria, Tricladida, Terricola) Part I: Geoplaninae.'' Bulletin of Fujis Women's College. 29: 79-166. This definition, however, is incomplete regarding all anatomical structures currently considered in the definition of planarian genera. In 2023, ''Polycladus'' was discovered preying on a black snail, ''

Macrocyclis ''Macrocyclis'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Macrocyclidae. ''Macrocyclis'' is a monotypic genus, i.e. a genus that contains only one species. The single living species in this ge ...

peruvianus'', in the wild.

Etymology

The name ''Polycladus'' comes from

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

''πολύ'' (many) + ''κλάδος'' (branch), referring to the branched intestine. Despite the name, ''Polycladus'' is not a species of the flatworm order

Polycladida The Polycladida represents a highly diverse clade of free-living marine flatworms. They are known from the littoral to the sublittoral zone (extending to the deep hot vents), and many species are common from coral reefs. Only a few species are fo ...

, but rather of

Tricladida Planarians (triclads) are free-living flatworms of the class Turbellaria, order Tricladida, which includes hundreds of species, found in freshwater, marine, and terrestrial habitats.pp 3., "Planarians (the popular name for the group as a whole ...

. The specific epithet of the type-species, ''gayi'', commemorates French naturalist

Claude Gay Claude Gay, often named Claudio Gay in Spanish texts, (18 March 1800 – 29 November 1873), was a French botanist, naturalist and illustrator. This explorer carried out some of the first investigations about Chilean flora, fauna, geology and ge ...

References

{{Taxonbar, from=Q18583049 Geoplanidae Rhabditophora genera Fauna of the Valdivian temperate forests