Integrative description of two new tardigrade species from the rainforests of Kibale National Park, Uganda

African tropical forests are highly underexplored regarding microinvertebrate diversity, including tardigrades. Here, we describe two new tardigrade species from the genera Parahypsibius Gąsiorek et al., 2024 and Echiniscus C. A. S. Schultze, 1840, collected in the tropical rainforest of the Kibale National Park in southwestern Uganda. Species delimitation was based on an integrative approach combining morphological, morphometric, and molecular data.

Morphological analyses employed light and scanning electron microscopy, while molecular characterization used mitochondrial COI and nuclear 18 S rRNA, 28 S rRNA, ITS 1, and ITS 2 markers. Additionally, we report Echiniscus lineatus Pilato, Fontoura, Lisi and Beasley, 2008 from Uganda for the first time, providing new sequences and reconstructing haplotype networks using previously published genetic data of this species.

Phylogenetic analyses of subfamily Hypsibiinae Pilato, 1969 and genus Echiniscus clarify the relationships of the new taxa and place them within the broader phylogenetic context. Our study highlights the underestimated diversity of African tardigrades and demonstrates the importance of integrative taxonomy for species delineation. The new records from Kibale National Park provide also baseline data for understanding the distribution and phylogeny of tardigrades of the Central Africa.