A New Species of Fur Mite (Acari: Myobiidae) Parasitizing Laboratory Mice, With a Key to the Subgenus Myobia.

Abstract

Purpose: The genus Myobia (Acari: Myobiidae) includes obligate ectoparasites of rodents, with M. murismusculi being the most frequently reported species in laboratory mouse colonies worldwide. However, morphological overlap and nomenclatural confusion have long hindered accurate species identification. This study aims to describe a new fur mite species from Mus musculus and to distinguish it from M. murismusculi and related taxa using detailed morphological and morphometric analyses.

Methods: Fur mites were collected from laboratory mice in two facilities and examined using light and scanning electron microscopy. Morphological characters were described, measured, and illustrated. Sstandardized morphometric characters were analyzed across multiple Myobia species using principal component analysis (PCA) and permutational multivariate analysis of variance (PERMANOVA) to assess interspecific variation and species boundaries.

Results: The new species, Myobia murina sp. nov., differs from M. murismusculi by longer dorsal setae ve and si. PCA and t-SNE analyses revealed a distinct cluster for M. murina, and PERMANOVA confirmed significant morphological divergence from all examined congeners (R² = 0.873, p < 0.001). An updated identification key for female mites of the subgenus Myobia is also provided.

Conclusion: This study demonstrates the utility of morphometric approaches in mite taxonomy and confirms M. murina sp. nov. as a morphologically and statistically distinct species. Accurate species identification is essential for laboratory animal health management and fur mite diagnostics.