Preliminary Analysis of Phylogenetic Relationships of the Asian-Pacific Endemial Subterranean Amphipod Genus Pseudocrangonyx Among Families and Genera of Crangonyctoidean Amphipods Inferred by Partial LSU rDNA Gene Sequences

Abstract

To analyze the phylogenetic relationships of the genus Pseudocrangonyx within the superfamily Crangonyctoidea, we sequenced a partial LSU rDNA gene from four species (six specimens). The monophyly of Pseudocrangonyx and its affinity to Crymostygius were strongly supported by four reconstruction methods: neighbor-joining, minimum evolution, maximum-likelihood, and Bayesian inference. Current geographical distributions of the taxa studied and their phylogenetic relationships established in our study suggest that members of Pseudocrangonyctidae and Crymostygius diverged from a common Crangonyx-like ancestor in the Arctic Basin region of the northern hemisphere.

The complete mitochondrial genome of Pseudocrangonyx daejeonensis (Crustacea: Amphipoda: Pseudocrangonyctidae)

“…Pseudocrangonyctidae and Crangonyctidae, inhabit groundwater habitats in caves, springs, and hyporhea (Holsinger 1994 ). Although the previous study showed the monophyly of Crangonyctidae + (Pseudocrangonyctidae + the Icelandic subterranean Crymostygius ) (Sidorov and Gontcharov 2015 ), the precise phylogenetic relationship of the 14 crangonyctoidean families remains unresolved.…”

Checklist of the Amphipoda (Crustacea) from continental waters of Russia, with data on alien species

“…Seven genera out of the 110 identified (or 6.4%) belong to the paleolimnic complex (the genus Pseudocrangonyx presumably attributed to this group). It is the underground amphipods from the families Crangonyctidae and Pseudocrangonyctidae which are the most ancient freshwater inhabitants [Sidorov, Gontcharov, 2015].…”

“…However, their zoogeographical heterogeneity is of interest; the underground representatives belong to four biogeographic groups (see Table 4). Four groups could be identified, which differ markedly in their origin and evolution: 1) Holarctic group of the paleolimnic complex Crangonyx-Synurella; 2) a group of the Western Palearctic Niphargidae, related to the mesolimnic complex; 3) a group of the Far Eastern Pseudocrangonyctydae of unknown origin [Sidorov, Gontcharov, 2015], and 4) a group of the neolimnic Far Eastern Ganigamoera [Sidorov, 2010].…”

A New Species of the Genus Pseudocrangonyx (Crustacea: Amphipoda: Pseudocrangonyctidae) from Yonaguni Island, Southwestern Japan, and Historical Biogeographic Insights of Pseudocrangonyctids

“…The two exclusively subterranean amphipod families Niphargidae Bousfield, 1977, distributed mainly in Europe, (Copilaş-Ciocianu et al, 2019. Pseudocrangonyctidae is phylogenetically related to the Crymostygidae Kristjánsson and Svavarsson, 2004 distributed in Iceland, suggesting that their common ancestor was present in the Arctic Basin (Sidorov and Gontcharov, 2015). The distribution of the family, including Pseudocrangonyx, is restricted from subarctic to temperate zones.…”