• Citer

Phylogenetic structure and molecular species delimitation hint a complex evolutionary history in an Alpine endemic Niphargus clade (Crustacea, Amphipoda)

par Knüsel, Mara;Borko, Špela;Alther, Roman;Salussolia, Alice ;Flot, Jean-François ;Altermatt, Florian;Fišer, Cene;Stoch, Fabio
Référence Zoologischer Anzeiger, 306, page (27-36)
Publication Publié, 2023-09-01

Article révisé par les pairs

• Accès en ligne
• Détails
• Contenu
• Statistiques

Résumé :

Subterranean fauna is an important contributor to the global fauna, but it is still understudied and a large part of its taxonomy is not yet resolved. One species complex with unresolved taxonomy is the groundwater amphipod Niphargus ruffoi, endemic to the Alpine chain. Here, we used new samples from across the Alpine arc to review the taxonomic status of the entire clade, including the species N. ruffoi and Niphargus arolaensis. We sequenced four genetic markers from the collected specimens, assessed the phylogenetic position of N. ruffoi within the genus, and studied the structure of this species complex using four molecular species delimitation methods. We tested for recombination using the alignments of the concatenated nuclear rDNA genes. The phylogenetic analyses revealed high support for the monophyly of the studied species complex, defining two lineages (i.e., N. arolaensis and N. ruffoi) within the clade. Molecular species delimitation methods suggested that N. arolaensis is a single species, while N. ruffoi should be considered as a species complex of three (using ITS) to eight (using COI) putative species. Moreover, we found a discrepancy between the different nuclear ribosomal DNA markers, indicating a possible recombination with fragments of 28S DNA of N. ruffoi s. lat. present in the genome of N. arolaensis. For the above-mentioned reasons, the internal phylogenetic structure of N. ruffoi s. lat. could not be fully resolved. Moreover, no clear morphological evidence supported the molecular species delimitation. Consequently, no taxonomic changes were proposed. We postulate that this complex scenario was influenced by Pleistocene climate oscillations with subsequent fragmentation events and secondary contacts, making this an interesting study system to investigate the evolution and biogeography of Alpine clades.