The role of landscape evolution in the genetic diversification of a stream fish Sarcocheilichthys parvus from Southern China

Abstract

Sarcocheilichthys parvus (Cypriniformes: Gobionidae) is a stream fish which is endemic to sub-tropical coastal drainages in southern China, thus offering a valuable model for understanding how genetic divergence arises in stream-adapting freshwater fishes in this region. Using the mitochondrial Cyt b gene, integrative analyses of phylogeny, population demography, and ancestral area and paleo-drainage reconstructions are carried out to explicitly explore the role of landscape evolution in genetic diversification of S. parvus. The time-calibrated phylogeny of S. parvus indicates the splitting of two major lineages (A and B) at ∼3.66 Ma. Lineage A inhabits the Poyang Lake sub-drainage of the middle Yangtze River, Han River and Pearl River, and can be split into two sub-lineages (A-I and A-II), where sub-lineage A-II can be further sub-divided into three infra-sub-lineages (A-IIa, A-IIb and A-IIc). Except for the infra-sub-lineage A-IIc, which is restricted to the Han River and Pearl River, the other sub-lineages and infra-sub-lineages live exclusively in the Poyang Lake sub-drainage. Lineage B lives in the lower Yangtze River, Qiantang River, Jiaojiang River and Ou River, displaying close genetic relationships among the drainages. Rapid population expansion has occurred since the Late Pleistocene. Our findings indicate that the splitting of lineages A and B could be attributed to geographic isolation due to the Zhe–Min Uplift, acting as a biogeographic barrier before the late Early Pleistocene. Furthermore, the strong genetic divergence within Lineage A could be explained by the isolation role of the Nanling Mountains and Poyang Lake acting as an ecological barrier; while the lack of phylogenetic structure within Lineage B may have been the result of paleo-drainage connections or episodic freshwater connections during the eustatic low stand of sea level in the late Middle–Late Pleistocene.

Phylogeographic analysis revealed allopatric distribution pattern and biogeographic processes of the widespread pale chub Opsariichthys acutipinnis-evolans complex (Teleostei: Cyprinidae) in southeastern China

“…As a small resident stream fish, the pale chub might be prone to the alternation in landscapes and water systems, resulting in the formation of current phylogeographical structures. Recent phylogeographic studies on two gudgeon species have congruently revealed similar scenarios, in which the significant genetic differences between the coastal river populations and Yangtze River populations were attributed to the long-term isolation between these river drainages as a result of the orogenic events in southeastern China (Yang et al, 2022;Li M. et al, 2023). These findings, along with ours, emphasized the important role of the low mountains and hills in structuring the phylogeographic patterns of small freshwater fishes in southeastern China.…”

“…Our study found that several coastal river populations (population 13, FD; population 23, Bs; population 24, ZP; population 25, HA) exhibited higher nucleotide diversity than other populations due to the admixture of two major lineages (Figure 1A), while the remaining populations had a single lineage. Some previous studies focusing on both animals (e.g., Zhao et al, 2008;Li M. et al, 2023) and plants (e.g., Nettel et al, 2008;Havrdová et al, 2015) have attributed the elevated nucleotide diversity to a result of secondary contact. In our case, population 13 (FD) was originated from a small coastal stream (Tongshanxi River).…”

Pleistocene Landscape Dynamics Drives Lineage Divergence of a Temperate Freshwater Fish Gobio rivuloides in Coastal Drainages of Northern China

“…Two temporal patterns of rapid population expansion prior to the last glacial maximum (LGM, 0.026-0.019 Ma) and after the LGM detected in different lineages of G. rivuloides have also been reported in other East Asia freshwater fishes [10,80,81]. However, previous phylogeographic research of freshwater fishes in East Asia offers the strongest evidence of the pattern of rapid population expansion prior to LGM (e.g., [18,21,23,46,49]).…”

“…In the absence of a known genus Gobio fossil, we adopted the methods of previous studies [21,49] by reconstructing the time-calibrated Bayesian phylogeny of G. rivuloides and its close relatives to gain a secondary calibration point in BEAST v2.6.7 [56]. The Leuciscide were selected as the outgroup taxa of the Gobionidae based on the results of previous studies using multi-loci nuclear data [57,58] or mitochondrial genome data [59].…”

“…Despite numerous phylogeographic studies of the influence of past drainage connections on the patterns of lineage distributions in southern China (e.g., [23,[45][46][47][48][49]), our understanding of how changes in the drainage landscape have shaped the phylogeographic patterns of freshwater fishes in northern China is still greatly limited. Using G. rivuloides as a model and the statistical analysis of phylogeography based on the cytochrome b gene, the present study attempts to further our understanding of the origins of the intraspecific genetic divergence of freshwater fishes in northern China.…”