Taxonomy

Recent genomic phylogenies have generated new robust classifications of actinopterygian fishes, making possible greater nomenclatural stability, but genus-level classifications of groups like the diverse catfish subfamily Trichomycterinae are still unclear, containing ill-defined paraphyletic taxa. The focus of the present study is the Trichomycterus Lineage (TL), a clade with great morphological diversity, containing about 170 species widely distributed in South America, occurring in the most important biodiversity hotspots of the world, such as the Atlantic Forest, Cerrado, and the Tropical Andes. Most species are small, but at least one reaches about 400 mm of total length, being used as food and depicted in pre-Hispanic Andean ceramics. Based on a comparative morphological analysis, mainly using osteological characters, supported by concordant genomic phylogenies, a new classification at the genus level is here provided. Many morphological features delimiting TL genera seem to be related to ecological adaptations. Nine genera are here recognised of which five are new. Recognition of the new genera will allow easier descriptions of new species and consequently better biodiversity estimates.

The genus Auricularia holds significant ecological importance due to its role in wood decaying and notable economic value as both an edible and medicinal resource. This study investigates the diversity of Auricularia species in Colombian Andes using an integrative approach. Species identification was based on macromorphological and micromorphological characteristics, alongside molecular analyses employing ITS and LSU markers. A total of 184 sequences of 81 specimens and 30 species were used to construct a phylogenetic tree including RPB2 marker sequences taken from GenBank. The results revealed six Auricularia species in the Colombian Andes: A. subglabra, A. cornea, A. fuscosuccinea, A. nigricans, A. brasiliana, and the newly described A. ibaguensis. This study provides morphological descriptions, distribution records, and interspecific distinctions, aligning these taxa with four out of the five recognized Auricularia species complexes. Novel sequences deposited in GenBank enhance taxonomic resolution, particularly within the A. cornea complex. These findings contribute new insights into the taxonomy of Auricularia in the Colombian Andes and emphasize the need for further research on Neotropical species, which may show significant differences from taxa in other biogeographic regions.

Astigmata is a diverse lineage of mites with significant ecological, medical, and economic importance, yet higher-level relationships within the group remain contentious due to incongruent morphological and molecular data. Here, we integrate multigene data with comparative morphology and ecological traits to reassess phylogenetic relationships, with a focus on the newly described family Lycoglyphidae fam. nov. associated with puffball fungi. Phylogenetic analyses recover Lycoglyphidae within a well-supported cluster—the AR cluster—comprising Acaridae sensu novo, Rhizoglyphidae sensu novo, and several additional related lineages. Within this framework, previously unrecognized lineages such as Pontoppidaniidae (intertidal seaweed habitats) and Cerophagidae (bee-associated) are supported as monophyletic, showing ecological conservatism. Our phylogeny indicates that mating position is phylogenetically structured, with retroconjugate mating prevalent in the AR cluster (except Histiostomatoidea) and many other lineages, while proconjugate mating is present only in two lineages, Hemisarcoptoidea+Glycyphagidae and Rosensteiniidae+Aeroglyphidae. Finally, to facilitate identification and future research, we provide a taxonomic description of new taxa (Lycoglyphidae with Lycoglyphus gen. nov., Obelacarus gen. nov., and Viedebanttia) and a comprehensive key to the families and genera of Acaroidea based on both adults and deutonymphs. Our results clarify some higher-level relationships within Astigmata, indicate the importance of integrating molecular, morphological, and ecological evidence, and provide a practical resource for identification and comparative studies.