Radiophryidae (Ciliophora, Astomatia): uma revisão histórica e cienciométrica

Abstract

Ciliates of the subclass Astomatia live as endosymbionts of various aquatic and terrestrial metazoans and comprise one order and nine families. Within the order Astomatia, the family Radiophryidae stands out as a group of symbiotic ciliates characterized by a complex system of skeletal fibers and a ciliary organization forming an apical “V” system. In the present study, we conducted a historical review and a scientometric analysis of publications concerning the family Radiophryidae (Astomatia), with the aim of compiling available information and approaches related to this taxon. To retrieve scientific articles addressing Radiophryidae, several keywords (family, subfamilies, and genera names) were searched across Google Scholar, PubMed, Web of Science, and Scopus databases. The results of the historical review and scientometric analysis highlight the progressive development of scientific knowledge on the family over time. Morphological analyses remain useful for delimiting certain groups, although they should not be employed as the sole criterion. Given the diversity of convergent evolutionary traits, the suborder Astomatia still lacks a clear morphological framework. Conversely, molecular analyses indicate that Astomatia is polyphyletic. The family Radiophryidae is supported as a monophyletic clade based on both morphological and genetic evidence. Traditional taxonomy relied primarily on descriptions of body structures, such as the apical “V” system and attachment apparatus, to establish the group. This approach remains valid at the genus level but poses greater challenges at the species level. To address this issue, an integrative approach combining morphological and molecular techniques has proven effective, offering new hypotheses for understanding taxa and their evolutionary relationships. The review and scientometric data strongly suggest the need for integrative approaches in the description and redescriptions of ciliates within this group.