A threefold, specimen-saving morphological protocol for aquatic micrometazoans: proof of concept with an integrative re-investigation of the rare freshwater gastrotrich Dichaetura surreyi Martin, 1990
摘要
We developed a threefold morphological protocol to maximize taxonomic data gathering for aquatic micrometazoans and applied it to Dichaetura surreyi Martin, 1990 in farm ditches in Northwest Germany (East Frisia) as proof of concept. To maximize morphological and anatomical information from the limited number of individuals, we applied a specimen-saving workflow that combines light microscopy, confocal laser scanning microscopy, and scanning electron microscopy on the same specimens. This approach refines the taxonomic understanding of D. surreyi, confirms originally described morphological features, and complements them with previously undescribed muscular architecture and cuticular characters for Dichaeturidae. We provide mitochondrial sequence data and a maximum-likelihood gene tree for Paucitubulatina placing D. surreyi as a potential sister to Polymerurus. The neotype designation and deposition of mitochondrial barcode sequences establish reference material for future research, and help address knowledge gaps in this poorly known family.