Pacific and Atlantic Lepeophtheirus salmonis (Krøyer, 1838) are allopatric subspecies: Lepeophtheirus salmonis salmonis and L. salmonis oncorhynchi subspecies novo

BMC Genetics

Kevin Alan Glover²  Ole Torrissen¹  Rasmus Skern-Mauritzen¹ 

[1] Institute of Marine Research, P.O. Box 1870, Nordnes. 5817, Bergen, Norway;Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway

关键词: Phylogenetics;    Copepodids;    Reproduction;    Salmon louse;    Sea lice;    Subspecies;    COI;    Hybrid fitness;   

Others  :  866618
DOI  :  10.1186/1471-2156-15-32

 received in 2013-09-23, accepted in 2014-03-10,  发布年份 2014

【 摘 要 】

Background

The salmon louse Lepeophtheirus salmonis is a parasitic copepod that infects salmonids in the Pacific and Atlantic oceans. Although considered as a single species, morphological and biological differences have been reported between lice from the two oceans. Likewise, studies based on nucleotide sequencing have demonstrated that sequence differences between Atlantic and Pacific L. salmonis are highly significant, albeit smaller than the divergence observed between congeneric copepod species.

Results

We demonstrated reproductive compatibility between L. salmonis from the two oceans and successfully established F2 hybrid strains using separate maternal lines from both the Pacific and Atlantic. The infection success for the F2 hybrid strains were similar to results typically observed for non hybrid lice strains in the rearing facility used. Lepeophtheirus salmonis COI and 16S sequences divergence between individuals from the Pacific and the Atlantic oceans was high compared to what may be expected within a copepod species and phylogenetic analysis showed that they consistently formed monophyletic clades representing their origin from the Pacific or Atlantic oceans.

Conclusions

Lepeophtheirus salmonis from the Pacific and Atlantic oceans are reproductively compatible at least until adults at the F2 hybrid stage, and should not be regarded as separate species based on reproductive segregation or sequence divergence levels. Reported biological and genetic differences in L. salmonis seen in conjunction with the reported genetic diversity commonly observed between and within species demonstrate that Atlantic and Pacific L. salmonis should be regarded as two subspecies: Lepeophtheirus salmonis salmonis and L. salmonis oncorhynchi subsp. nov.

【 授权许可】

   
2014 Skern-Mauritzen et al.; licensee BioMed Central Ltd.

【 图 表 】

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