Unexpected endemism in the Daphnia longispina complex (Crustacea: Cladocera) in Southern Siberia

Abstract

The biological significance of regional cladoceran morphotypes in the montane regions of the central Palearctic remains poorly understood. In the Holarctic Daphnia longispina complex (Cladocera: Daphniidae), several variants, lineages and species have been proposed as endemic for Southern Siberia. Daphnia turbinata Sars, for example, named after its unusual head shape, is known only from Southern Siberia. Here we sequence DNA of Daphnia from three mitochondrial genes (12S rRNA, 16S rRNA, and NADH dehydrogenase subunit 2, ND2 ) from 57 localities in Russia and Mongolia (the majority being from Southern Siberia) and place them in evolutionary context with existing data. Our aim was to examine regional endemism of the Daphnia longispina complex in Southern Siberian; to improve the phylogenetic understanding with improved taxonomic and regional sampling, and to better understand the influence of Pleistocene glaciation on the biogeography of these lineages. At least three lineages showed genetic evidence for endemism in Southern Siberia. There was strong support for D . turbinata as a sister lineage to to D . longispina / D . dentifera . Another endemic, Siberian D . cf. longispina , is a sister group to the longispina group in general. Within D . longispina s. str. there was an endemic Siberian clade with a western range boundary near the Yenisei River Basin. Gene flow estimates among populations (based on F ST values) were very low for clades of D . longispina on a regional (the original 12S dataset), and on a pan-Eurasian (the extended 12S dataset) scale. Negative values of Fu’s F S and Tajima’s D tests prevailed for the species examined with significant values found for two D . longispina clades, D . dentifera , D . galeata and D . cristata . Our results support the notion that Southern Siberia is an important biogeographic region for cladocerans as it contained unexpected diversity of endemics (such as D . turbinata , D . cf. longispina and lineages of D . umbra and D . longsipina s.str.) and from being the geographic meeting place of expanding postglacial lineages from eastern and western refugia.

Crustaceans in the Meiobenthos and Plankton of the Thermokarst Lakes and Polygonal Ponds in the Lena River Delta (Northern Yakutia, Russia): Species Composition and Factors Regulating Assemblage Structures

“…Phylogeographic studies confirm a special status of the Beringian zone and a specific history of the taxon dispersion there. As a result of the works on the cladoceran taxa distribution, the separation of two main biogeographic provinces (Western Holarctic Province and Beringian Province) of the Holarctic with a transitional zone in Eastern Siberia was shown [54][55][56]. Crustaceans species here can differ from that in other regions due to the differences in geological and climatic events during the last glacial maximum and previous Pleistocene glacial cycles.…”

Lineage diversity and gene introgression in freshwater cladoceran crustaceans of the Chydorus sphaericus species complex

“…Previous studies have already shown a rich genetic/haplotype diversity of cladocerans in the Eastern Palearctic (e.g., Bekker et al 2018; Ma et al 2019 b ), especially in Siberia (Zuykova et al 2019). Consistent with this, we detected high haplotype diversity in C. sphaericus populations in China.…”

“…For example, the only representatives of the D. longispina species complex found in China to date are D. galeata Sars, 1863, D. longispina Muller, 1776 and D. dentifera Forbes, 1893 (e.g., Xu et al 2018; Ma et al 2019 a ). These three and additional species from this complex were detected in Siberia, to the north of China (Zuykova et al 2018; Zuykova et al 2019). A high species diversity of cladocerans is not always the rule (even in the same geographical region), because different species have different demographic histories (e.g., Zuykova et al 2018), as well as different evolutionary and biogeographical histories (Kotov et al 2016).…”

“…Surprisingly, we detected only one lineage of C. sphaericus from the Qinghai-Tibetan Plateau, suggesting a single taxon across all the sampled sites there. It has been suggested that the unique ecosystem of the Qinghai-Tibetan Plateau, together with the existence of several potential glacial refugia since the Pleistocene, could provide favorable environments to form and maintain high species/lineage diversity (Zheng and Rutter 1998), as has recently been found in the Altai and Sayan Mountains of Southern Siberia (Zuykova et al 2019). It is tempting to suggest that the low lineage diversity of C. sphaericus on the Qinghai-Tibetan Plateau can be explained by historical events: the uplift of this plateau mainly occurred in the Miocene (Mulch and Chamberlain 2006), perhaps leaving insufficient time for lineage divergence there.…”

Lineage diversity, morphological and genetic divergence in Daphnia magna (Crustacea) among Chinese lakes at different altitudes

“…The observed phylogenetic structure of D. magna could be explained by strong founder effects that are persistent through time (De Meester et al, 2002), by genetic drift (De Gelas & De Meester, 2005), or local adaptation (Boersma et al, 1999). Indeed, a strong founder effect has been recently demonstrated in high-altitude D. longispina populations from the Altai and Sayan Mountains (Zuykova et al, 2019).…”