Fig. 3

Maximum likelihood topology of small subunit ribosomal DNA from 54 myxosporeans, rooted to Chloromyxum leydigi and C. riorajum (infecting cartilaginous fishes). Bootstrap support values and posterior probabilities are shown at the nodes; solid black dots indicate full support for that node. Novel sequences from this study are in bold and contained within the Paramyxidium Clade (lilac box). The Paramyxidium clade forms a robust sister clade relationship with Myxidium clade (sensu stricto) (red box) and the Chloromyxum clade (green box). The dashed green box within the Chloromyxum clade shows species that infect the gall-bladder (GB) of cypriniform fishes. Nodes with a red asterisk indicate that the common ancestor was likely to have been a renal-infecting myxosporean. The Platysporina (blue box) forms a fully supported sister clade to this Paramyxidium / Myxidium (s.s.) / Chloromyxum grouping and includes the Myxobilatidae (grey box). Highlighted within the Myxobilatidae, by a dashed black box, is the Chloromyxum schurovi sub-clade that contains other renal isolates from eels that have been reported as Myxidium giardi and Zschokkella sp. Basal to these main clades is the hepatic biliary clade, a well-supported clade which contains numerous taxa, some of which infect vertebrates other than fish