Adeonidae; new species; redescription.

Bryozoans comprise aquatic invertebrates mainly found in all types of substrata and habitats. In Brazil, approximately one third of the described bryozoan diversity has been described in the past two decades (ca. 150 species). Among the most common genera found in shallow waters in Brazil, Reptadeonella Busk, 1884 is reported from Ceará to São Paulo and it is considered abundant in intertidal zone, with a wide morphological plasticity. The main revision on this genus was published in 2015, but morphological and morphometric patterns of that genus are still poorly understood. Thus, this work aims to provide characterization of the morphological patterns Reptadeonella species from Brazil, redefing the characters to be used to distinguish species. The type specimens of all seven species of Reptadeonella originally described from Brazil were analyzed, besides data on newly collected samples (280 specimens) from different localities in Brazil (Rio Grande do Norte, Paraíba, Pernambuco, Bahia and Espírito Santo). In laboratory, specimens were analized under stereoscopic microscope to provide the descriptions of skeletal morphology and to identify morphotypes. Part of studied material was examined under scanning electron microscope to provide additional data to recognize new characters and to perform morphometric analyses. The redescriptions of four species are provided, one of which species is recognized as a complex, and three new species are described. Morphological plasticity in diagnostic features were detected according to colony astogeny and ontogeny. Additionally, the analysis of colonies comprising newly budded and older zooids provided the recognition of morphological variations and the occurrence of heterozooids previously unknown for the three redescribed species. A tabular identification key for all living species of the genus, as well as discussions regarding diagnostic taxonomic features are presented.