FIGURE 1. A in DNA barcodes unite two problematic taxa: the meiobenthic Boreohydra simplex is a life-cycle stage of Plotocnide borealis (Hydrozoa: Aplanulata)

FIGURE 1. A. ML topology for all publically available 18S sequences (n=519) of Hydroidolina, showing the positions of Plotocnide borealis and Protohydra leuckarti within Aplanulata. SH-like branch support values are shown at the nodes, as well as bootstrap indices if exceeding 60. Uncollapsed topologies are provided as Supplementary Figures at https://dx.doi.org/ 10.6084/m9.figshare.3406654.v3. B. SEM of the polyp stage previously known as Boreohydra simplex, the mouth is marked by (*). C. Live image of the medusa stage of Plotocnide borealis, tentacles contracted.