Multiple genetic sources facilitate the northward range expansion of an intertidal oyster along China's coast

Abstract

Coastal artificial structures on the former mudflats provide available habitats for the rocky intertidal species which can establish new populations in these emerging habitats over their former distribution range limits. As a former southern species, the oyster Crassostrea sikamea has become a pioneer and rapidly invaded the artificial shorelines in northern China. We used a seascape genomics approach to investigate the population structure and genetic sources of C. sikamea on the coastal artificial structures, which is crucial for understanding the genetic mechanisms driving species distribution range expansion and invasion pathway of intertidal species. Five C. sikamea populations, including two artificial substrate populations (WGZ and ZAP), one oyster reef population (LS), and two natural rocky shore populations (ZS and XM), were measured using single nucleotide polymorphism (SNPs) obtained from double digest restriction‐site associated DNA sequencing (ddRAD‐Seq). Redundancy analyses (RDA) were implemented for investigating the relationship between local temperature variables and the temperature adaptability of C. sikamea. Genetic diversity, direction and strength of gene flow, and population structure all revealed that the LS and ZS populations were the genetic sources for the oyster populations on the emerging northern coastal artificial structures. Results of RDA showed that there were different adaptive potentials for northern and southern populations to local temperature variables and the oyster reef population which frequently suffers from heat stress owned high heat adaptability. The ZS population as a genetic source nearby the Yangtze River estuary provided mass larvae for the northern populations, and the other genetic source, the heat‐tolerant LS population, in the oyster reef played an important role in the post‐settlement success by providing preadapted genotypes. These results highlight the importance of multiple sources with divergent adaptative capabilities for biological invasion, and also emphasize the importance of the oyster reef in coastal biodiversity and conservation.

Pushed waves, trailing edges, and extreme events: Eco‐evolutionary dynamics of a geographic range shift in the owl limpet, Lottia gigantea

“…Likewise, population structure between the expanded range and core populations was found for the intertidal gastropod, Nerita yoldii , along the Chinese coast (Wang et al., 2022) and the octopus Octopus tetricus , along the western Australian coast (Ramos et al., 2018). In contrast, our results mirror those seen in a range expansion of the sea urchin, Centrostephanus rodgersii (Banks et al., 2010), the oyster, Crassostrea sikamea (Hu & Dong, 2022), and the barnacle, Tetraclita rubescens (Dawson et al., 2010), showing no evidence of population structure or a decrease in genetic diversity at the expanded‐range edge.…”

Thermal heterogeneity is an important factor for maintaining the genetic differentiation pattern of the pelagic barnacle Lepas anatifera in the northwest Pacific

“…anatifera in the northwest Pacific. As previous studies reported (Han & Dong, 2020 ; Hu & Dong, 2022b ), the genetic variations among populations of the mussel Mytilus galloprovincialis and the oyster Crassostrea sikamea were significantly correlated with the environmental temperatures. In the present study, the results of RDA analysis revealed that local temperature, especially the low temperature in January (e.g., T1) was a significant factor influencing the distribution patterns of putatively adaptive genetic variation among populations.…”

“…These results implied that temperature heterogeneity might be a physical barrier that prevents the gene flow between lineages with different thermal tolerances and plays a vital role in maintaining the genetic differentiation patterns of L. anatifera from the fixed buoys in the NWP.The redundancy analysis based on the genotype-environment association method further confirmed the roles of temperature heterogeneity in maintaining the genetic differentiation of L. anatifera in the northwest Pacific. As previous studies reported(Han & Dong, 2020;Hu & Dong, 2022b), the genetic variations among populations of the mussel Mytilus galloprovincialis and the oyster Crassostrea sikamea were significantly correlated with the environmental temperatures.…”

Perspectives of invasive alien species management in China

“…From a biogeographical perspective, understanding the role of climate change and human activities in driving the distribution of alien species is crucial for predicting adaptive capabilities and future invasion potentials. A study by Hu and Dong (2023) on the marine species Crassostrea sikamea demonstrated that the rapid northward expansion of the southern population, in response to climate change and coastal development, was facilitated by multiple sources of divergent thermal adaptability. These findings provide valuable insights into the genetic origins and dispersal mechanisms of intertidal oysters during their northward shift along China's coast, highlighting the importance of rapid adaptation to local environments in driving distribution shifts and preserving population viability at the distribution edge.…”