Microeucariotos ciliados do gênero Lambornella Keilin, 1921 (Ciliophora, Tetrahymenidae): análise cienciométrica e investigação sobre a sistemática e evolução de Lambornella trichoglossa Foissner, 2003

Abstract

This dissertation is composed of three chapters that collectively address historical, scientometric and molecular aspects of ciliates of the genus Lambornella Keilin, 1921 (Ciliophora, Tetrahymenidae), aiming to integrate dispersed information and contribute to a systematic and evolutionary understanding of the group. The first chapter presents a historical and taxonomic review of the genus Lambornella, analyzing the scientific output accumulated since the original description of the genus in 1921. The major thematic areas explored over the decades were examined, with emphasis on morphological descriptions and on controversial aspects of taxonomic classification. This approach highlighted knowledge gaps and inconsistencies in the literature, while providing an updated overview of the state of the art of the genus, identifying key points that require further investigation. In the second chapter, a scientometric analysis of the literature on Lambornella between 1921 and 2024 was conducted, with the aim of mapping the dynamics and trends of scientific publications related to the group. The results revealed an uneven distribution of research efforts, showing a scarcity of studies on Lambornella stegomyiae in contrast to the extensive investigation of the parasite–host relationship involving Lambornella clarki. It was also observed that Lambornella trichoglossa has a detailed morphological description but lacks deeper ecological and molecular analyses. The third chapter presents data on Lambornella trichoglossa, collected from phytotelmata of Portea petropolitana in the Zona da Mata of Minas Gerais, Brazil. Molecular sequences (18S rDNA and COI) from the GenBank database were used for phylogenetic analyses and computational species delimitation. The results confirmed L. trichoglossa as an independent evolutionary lineage and provided robust evidence of its ancestral symbiotic condition, contributing to a better understanding of evolution within the family Tetrahymenidae. Moreover, the molecular analyses raised considerations regarding the validity of the genus Lambornella, opening avenues for future taxonomic revisions. Thus, this dissertation brings together complementary approaches, historical review, scientometrics, and molecular data that, when integrated, offer new perspectives for the systematics and evolution of Lambornella, as well as for understanding ciliates inhabiting phytotelmic environments.