Phylogeny of hydrothermal vent Iphionidae, with the description of a new species (Aphroditiformia, Annelida) Author McCowin, Marina F. Author Rouse, Greg W. text ZooKeys 2018 779 89 107 http://dx.doi.org/10.3897/zookeys.779.24781 journal article http://dx.doi.org/10.3897/zookeys.779.24781 1313-2970-779-89 7ED3734C37F74ABF89B6A12A2A56B216 7ED3734C37F74ABF89B6A12A2A56B216 Thermiphione Hartmann-Schroeder , 1992, emended Type species. Thermiphione tufari Hartmann-Schroeder , 1992 Diagnosis (emended). Ventrally flattened, short, oval-shaped body. Between 28 and 32 segments in adults, with 13 or 14 pairs of elytra on segments 2, 4, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 26 (and 27, if 14 pairs) that cover dorsal side. Elytra rounded, covered with polygonal and/or hexagonal areas with lattice-like areolae; may exhibit papillae along elytral margins and on elytral surface near margins. Bilobed prostomium square to oval, merged with segment 1, with short, smooth, bulbous palps. Lateral and median antennae absent. Eyes absent. Segment 1 with paired enlarged anterior cirri (sensu Rouse and Pleijel 2001 ; = tentacular cirri), bearing each pair on a tentaculophore with an acicula and capillary chaetae. Mouth anterior, not ventral. Eversible pharynx with papillae and two pairs of jaws. Segment 2 bears first pair of elytra and parapodia, spherical papillae. Segment 3 barely visible dorsally, with parapodia wedged between segments 2 and 4. Segments 4 and 7 bear spherical ventral papillae. All parapodia biramous: notopodia rounded and much smaller than neuropodia, with bundles of thin, feathered notochaetae; neuropodia large with thicker, single-tipped neurochaetae. Dorsal cirri with short papillae and cylindrical cirrophores. Ventral cirri much smaller than dorsal cirri, short and cirriform. Pygidium inconspicuous, lacking anal cirri. Remarks . Hartmann-Schroeder's (1992) diagnosis of Thermiphione has been amended to accommodate the inclusion of Iphionella risensis and Thermiphione rapanui sp. n. The genus now comprises Thermiphione fijiensis (Figure 5A, D), T. risensis (Figure 5B, E), T. tufari (Figure 5C), and T. rapanui sp. n (Figs 6-9). The morphology of these taxa and phylogenetic evidence suggests that segment and elytral numbers are more variable than in the previous diagnosis. Thermiphione all have smooth palps, but this is plesiomorphic for Iphionidae . The absence of eyes may be an apomorphic state, depending on the eventual placement of Iphionella philippinensis , which was not included here owing to the lack of material for DNA sequencing. Similarly, the loss of lateral antennae may also be an apomorphy for Thermiphione once the position of Iphionella philippinensis and Iphionides glabra , which also lack them, is resolved. Figure 5. Dorsal and ventral micrographs of species in Thermiphione . Scale bars represent 5 mm. A Thermiphione fijiensis (SIO-BIC A7975), dorsal B Thermiphione risensis (SIO-BIC A6326, was Iphionella risensis ), dorsal C Thermiphione tufari (SIO-BIC A7973), dorsal D Thermiphione fijiensis (SIO-BIC A7975), ventral E Thermiphione risensis (SIO-BIC A6326), ventral.