Molecular analysis of Arctic material of Dendronotus robustus and Dendronotus velifer
The present molecular analysis shows that there are two distinct species under the name Dendronotus robustus, corresponding to D. robustus Verrill, 1870 and D. velifer G.O. Sars, 1878. Of the sampled specimens, 11 belonged to the former species and five to the latter. Minimal uncorrected p-distances for the COI gene are significantly different between both species, with a range of 8.74% ±1.24%. Distances within D. robustus group are within 0.71%. Distances within D. velifer group are up to 0.54%, but distances between D. robustus and D. velifer groups reach 9.34%. Results obtained by PopART both for the COI and for 16S genes showed a network of haplotypes that clearly clustered into two groups coincident with the species D. robustus and D. velifer (Figure 4a, b).