Application of COI Primers 30F/885R in Rotifers to Regional Species Diversity in (Sub)Tropical China

Abstract

Rotifers are the most diverse group in freshwater zooplankton and play an important role in food webs and ecosystems. DNA barcoding has become a useful approach to investigate species diversity at local and regional scales, but its application is still limited by efficient primers for the group. To test a pair of primers 30F/885R recently designed for rotifers, we applied them to investigating regional species diversity in the freshwater of South China. We sequenced the cytochrome c oxidase subunit I (COI) gene of rotifers collected from the investigated 23 reservoirs in a large river basin and obtained 145 COI sequences from 33 species in 14 genera. The mean PCR success rate for all tested species was 50%. The 145 sequenced mtCOI in this study covered 33 of 64 identified morphological taxa, including most of the common species in the basin. The intraspecific genetic distance was calculated with a K2P model for 24 rotifer species occurring in the quantitative samples, in which 15 rotifers, such as Keratella cochlearis and Brachionus calyciflorus, had a genetic distance higher than 5%. The high intraspecific genetic differentiation indicates that cryptic species are probably common in (sub)tropical China.

Single Cell Analysis Reveals a New Microsporidia-Host Association in a Freshwater Lake

“…Even though Kellicottia sequences grouped into two clades in the phylogenetic analysis, species determination is challenging due to high intraspecific variation of identity percent which can be higher than 20% for rotifers (Fig. S2b) [15].…”

The gems of the Middle-East: Unveiling the biodiversity of Monogonont rotifers in temporary waterbodies of Israel

“…Among the most highly represented species in the 26 temporary ponds were Hexarthra mira , Polyarthra vulgaris and Brachionus quandridentatus . These species comprise species-complexes (García-Morales & Domínguez-Domínguez, 2019; Moreno et al, 2017; Zhang et al, 2021) which suggests that their widespread distribution among different climatic regions may be attributed to the presence of different cryptic entities with distinct ecological requirements. This phenomenon has been previously observed in other rotifer taxa such as Brachionus plicatilis and Brachionus calyciflorus , which were once thought to have a ubiquitous distribution, but were later found to be species complexes with relatively restricted ecological niches (Gabaldón et al, 2017; Zhang et al, 2018; Walczyńska et al, 2023).…”