Fig. 3

Unrooted Bayesian inference (BI) tree as reconstructed from a cox1 alignment (643 bp). Sequences of S. nebaliae form a cluster, which again groups together with the P. annulatus sequence. In addition, the distance from the crustacean cluster (Nebalia pseudotroncosoi and Penaeus vannamei) to the branching of the nematode Caenorhabditis elegans is smaller than to the nodes, from which seisonid species branch off. Divergence of a previously published cox1 sequence for S. nebaliae [37] and its newly discovered counterpart (haplotype B) is not resolved in the graphic due to high identity. Support values correspond to the frequency of a branch in the posterior distribution. Asterisks (*) highlight newly generated sequences. Tree reconstruction was conducted with MrBayes v. 3.2.7a based on the GTR-G substitution model. Visualization was performed using iTOL. For nd1 tree, see Figure S1 in Additional file 1