The genera of the Neotropical armored catfish subfamily Loricariinae (Siluriformes: Loricariidae): a practical key and synopsis. Author Raphael Covain Author Sonia Fisch-Muller text Zootaxa 2007 1462 1 40 http://www.zoobank.org/urn:lsid:zoobank.org:pub:D1F13841-BD7B-4D00-B57D-9CBEC187B83C journal article z01462p001 D1F13841-BD7B-4D00-B57D-9CBEC187B83C Rhadinoloricaria Isbruecker & Nijssen, 1974 . Type species: Loricaria macromystax Guenther , 1869 . Holotype : BMNH 1869.5.21.8 , Peru , Amazon River . Gender: feminine. This monotypic genus is distributed in the upper Amazon and Orinoco River basins, Essequibo, and Tocantins drainages. Although poorly known and uncommon in collections, Rhadinoloricaria is known to occur over sandy substrates. Ecological and behavioral data are unavailable. Most studies of Rhadinoloricaria are based on the holotype, which is in a poor state of preservation (particularly its mouth, which is one of the most important features for the study of this group). The holotype is an adult with complete abdominal plate cover; smaller specimens have incomplete abdominal plate cover forming a double median row of platelets. This feature, which is also observed in Apistoloricaria , Crossoloricaria , and one species of Dasyloricaria , could reflect a common developmental pattern of abdominal plates among these taxa. Consequently, its use as a diagnostic feature should be rejected (see Crossoloricaria above).