TY - JOUR
T1 - The rapid, mass invasion of New Zealand by North American Daphnia “pulex”
AU - Ye, Zhiqiang
AU - Williams, Emily
AU - Zhao, Chaoxian
AU - Burns, Carolyn W.
AU - Lynch, Michael
N1 - Funding Information:
We thank Joachim Mergeay the insightful comments and suggestions on dealing with the taxonomy confusion in the species complex. We thank Wei‐chin Ho for helpful discussions and Samiullah Khan, Marc Schallenberg, and John McCallum for their help in sampling. This work is supported by NIH grant R35‐GM122566‐01 to Michael Lynch, financial support from Alan Wilson at Otago and the University of Otago to Carolyn Burns. Daphnia pulex
Publisher Copyright:
© 2021 Association for the Sciences of Limnology and Oceanography.
PY - 2021/7
Y1 - 2021/7
N2 - Nonindigenous members of the Daphnia pulex complex have been found in many lakes in New Zealand (NZ) in the past 20 years, suggesting a recent invasion. However, very little is known about the precise phylogenetic origin of invasive Daphnia, whether each lake is invaded by a single clone or multiple clones, the lineage of the invasive clones, and whether they are obligately asexual clones. Furthermore, the source and time of arrival of the invasive genotype(s) are unclear. We address these questions by genomic sequencing of Daphnia populations from 13 lakes in the South Island and 1 lake in the North Island, NZ. All biallelic sites in these NZ populations have similar numbers of reads for the two parental alleles, suggesting each NZ population originates from a single asexual clone. Based on 25,643 monomorphic lineage-specific markers, the invasive Daphnia in the South Island were found to be Daphnia pulicaria Forbes, while those in the North Island are hybrids of D. pulicaria Forbes and D. cf. pulex sensu Hebert. Both the South and North Island Daphnia are phylogenetically clustered with North American Daphnia, thereby suggesting their North American origins. We found also that all South Island clones contain identical mitochondrial genomes, suggesting the origin and proliferation from a single founder clone, which we experimentally verified to be an obligate asexual. Estimates from molecular data imply a colonization time for the South Island clones of ~ 60 years ago, with a likely invasion route associated with the introduction of salmonids from North America.
AB - Nonindigenous members of the Daphnia pulex complex have been found in many lakes in New Zealand (NZ) in the past 20 years, suggesting a recent invasion. However, very little is known about the precise phylogenetic origin of invasive Daphnia, whether each lake is invaded by a single clone or multiple clones, the lineage of the invasive clones, and whether they are obligately asexual clones. Furthermore, the source and time of arrival of the invasive genotype(s) are unclear. We address these questions by genomic sequencing of Daphnia populations from 13 lakes in the South Island and 1 lake in the North Island, NZ. All biallelic sites in these NZ populations have similar numbers of reads for the two parental alleles, suggesting each NZ population originates from a single asexual clone. Based on 25,643 monomorphic lineage-specific markers, the invasive Daphnia in the South Island were found to be Daphnia pulicaria Forbes, while those in the North Island are hybrids of D. pulicaria Forbes and D. cf. pulex sensu Hebert. Both the South and North Island Daphnia are phylogenetically clustered with North American Daphnia, thereby suggesting their North American origins. We found also that all South Island clones contain identical mitochondrial genomes, suggesting the origin and proliferation from a single founder clone, which we experimentally verified to be an obligate asexual. Estimates from molecular data imply a colonization time for the South Island clones of ~ 60 years ago, with a likely invasion route associated with the introduction of salmonids from North America.
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U2 - 10.1002/lno.11780
DO - 10.1002/lno.11780
M3 - Article
AN - SCOPUS:85104821847
SN - 0024-3590
VL - 66
SP - 2672
EP - 2683
JO - Limnology and Oceanography
JF - Limnology and Oceanography
IS - 7
ER -