The cheilostomes Schizoporella unicornis (Johnston, 1847) and Schizoporella errata (Waters, 1878) have been used as model species in several ecological and taxonomic studies. However, these species have been consistently misidentified in a large percentage of such works. Here full taxonomic descriptions of both species, based largely on scanning electron micrographs of type specimens, are presented. A lectotype is chosen for S. errata and it is shown that the species described as "Lepralia unicornis? Johnson MS" from the Pliocene Coralline Crag by Wood (1844) is not conspecific with Johnson's L. unicornis introduced for Recent material three years later. This work has implications for the application of seemingly cosmopolitan species to the study of anthropogenic disturbance and identifies the need for molecular characterization of cryptic species complexes.

Verspoor, E., Consuegra, S., Fridjonsson, O., Hjorleifsdottir, S., Knox, D., Olafsson, K., Tompsett, S., Wennevik, V., and Garciá de Leániz, C. 2012. Regional mtDNA SNP differentiation in European Atlantic salmon (Salmo salar): an assessment of potential utility for determination of natal origin. – ICES Journal of Marine Science, 69: 1625–1636. The Atlantic salmon, Salmo salar, shows geographically structured differentiation at various classes of molecular genetic variation, among and within river stocks. Nuclear microsatellite locus variation at multiple loci has been exploited for more than a decade as a marker for the continental origin of fish caught at sea in distant-water fisheries. However, a simpler, more cost-effective, but still accurate, assignment can be obtained using a single microsatellite locus in combination with a mitochondrial DNA (mtDNA) single-nucleotide polymorphism (SNP) detected by restriction enzyme digestion. Following on from this, a preliminary study was made of the potential for using mtDNA SNP variation to enhance the resolving power and cost-effectiveness of within-continent assignment of European salmon as determined using microsatellites. Variation in 20 mtDNA regions, encompassing ∼43% of this genome, in 330 salmon from 29 rivers across Europe, was analysed. High levels of inter-individual and inter-river variation were found, as well as evidence of regional differentiation paralleling observed microsatellite differentiation. The observations indicate scope for using mtDNA SNPs along with microsatellites for genetically based assignment of European salmon to region and river of natal origin, but further study is needed.

BackgroundApproximately half of the mitochondrial genome inherent within 546 individual Atlantic salmon (Salmo salar) derived from across the species' North Atlantic range, was selectively amplified with a novel combination of standard PCR and pyro-sequencing in a single run using 454 Titanium FLX technology (Roche, 454 Life Sciences). A unique combination of barcoded primers and a partitioned sequencing plate was employed to designate each sequence read to its original sample. The sequence reads were aligned according to the S. salar mitochondrial reference sequence (NC_001960.1), with the objective of identifying single nucleotide polymorphisms (SNPs). They were validated if they met with the following three stringent criteria: (i) sequence reads were produced from both DNA strands; (ii) SNPs were confirmed in a minimum of 90% of replicate sequence reads; and (iii) SNPs occurred in more than one individual.ResultsPyrosequencing generated a total of 179,826,884 bp of data, and 10,765 of the total 10,920 S. salar sequences (98.6%) were assigned back to their original samples. The approach taken resulted in a total of 216 SNPs and 2 indels, which were validated and mapped onto the S. salar mitochondrial genome, including 107 SNPs and one indel not previously reported. An average of 27.3 sequence reads with a standard deviation of 11.7 supported each SNP per individual.ConclusionThe study generated a mitochondrial SNP panel from a large sample group across a broad geographical area, reducing the potential for ascertainment bias, which has hampered previous studies. The SNPs identified here validate those identified in previous studies, and also contribute additional potentially informative loci for the future study of phylogeography and evolution in the Atlantic salmon. The overall success experienced with this novel application of HT sequencing of targeted regions suggests that the same approach could be successfully applied for SNP mining in other species.