''Cratera'' 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 found in South America.

Description

The genus ''Cratera'' is characterized by having a leaf-shaped body. Most species are between 3 and 7 cm long. The hundreds of eyes distributed along the body are monolobulated, i.e., simple and circular. The copulatory apparatus has a permanent conical penis occupying the entire male cavity. The final portion of the ejaculatory duct, the channel that guides sperm through the penis, has an expanded cavity that resembles a volcanic crater. It is very similar to the related genus ''

Obama Barack Hussein Obama II (born August 4, 1961) is an American politician who was the 44th president of the United States from 2009 to 2017. A member of the Democratic Party, he was the first African American president in American history. Ob ...

'', the main difference being the presence of trilobulated eyes in the latter.

Etymology

The name ''Cratera'' is derived from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

word ''crater'' and refers to the cavity in the penis that resembles a

volcanic crater A volcanic crater is an approximately circular depression in the ground caused by volcanic activity. It is typically a bowl-shaped feature containing one or more vents. During volcanic eruptions, molten magma and volcanic gases rise from an ...

Species

There are 24 species assigned to the genus ''Cratera'': *'' Cratera anamariae'' Carbayo & Almeida, 2015 *'' Cratera arucuia'' Lago-Barcia & Carbayo, 2018 *'' Cratera assu'' Araujo, Carbayo, Riutort & Álvarez-Presas, 2020 *'' Cratera aureomaculata'' Rossi & Leal-Zanchet, 2017 *'' Cratera boja'' Araujo, Carbayo, Riutort & Álvarez-Presas, 2020 *'' Cratera crioula'' (E. M. Froehlich, 1955) *'' Cratera cryptolineata'' Rossi & Leal-Zanchet, 2017 *'' Cratera cuarassu'' Carbayo & Almeida, 2015 *'' Cratera hina'' (Marcus, 1951) *'' Cratera imbiri'' Araujo, Carbayo, Riutort & Álvarez-Presas, 2020 *'' Cratera joia'' (Froehlich, 1956) *''

Cratera nigrimarginata ''Cratera nigrimarginata'' is a species of land planarian found in Brazil. Description ''Cratera nigrimarginata'' is a medium-sized land planarian with an elongate and flat body, with parallel margins, reaching about in length. The dorsum ha ...

'' Rossi & Leal-Zanchet, 2017 *'' Cratera ochra'' Rossi, Amaral, Ribeiro, Cauduro, Fick, Valiati & Leal-Zanchet, 2015 *'' Cratera obsidiana'' Amaral, Boll & Leal-Zanchet, 2019 *'' Cratera paraitinga'' Araujo, Carbayo, Riutort & Álvarez-Presas, 2020 *'' Cratera picuia'' Lago-Barcia & Carbayo, 2018 *'' Cratera pseudovaginuloides'' (Riester, 1938) *'' Cratera steffeni'' Rossi, Fontoura, Amaral & Leal-Zanchet, 2014 *'' Cratera tamoia'' (E. M. Froehlich, 1955) *'' Cratera taxiarcha'' (Marcus, 1951) *'' Cratera tui'' Araujo, Carbayo, Riutort & Álvarez-Presas, 2020 *'' Cratera viridimaculata'' Negrete & Brusa, 2016 *'' Cratera yara'' (E. M. Froehlich, 1955)

References

{{Taxonbar, from=Q20686311 Geoplanidae Rhabditophora genera