Pycnophyes almansae sp nov and Pycnophyes lageria sp nov., two new homalorhagid kinorhynchs (Kinorhyncha, Homalorhagida) from the Iberian Peninsula, with special focus on introvert features

Two new species of homalorhagid kinorhynchs of the genus Pycnophyes, Pycnophyes almansae sp. nov. and Pycnophyes lageria sp. nov., are described from the Atlantic and Spanish waters of the Mediterranean Sea, using scanning electron microscopy and differential interference contrast microscopy. Pycnophyes almansae sp. nov. is recognized by the presence of middorsal elevations on segments 2-9, pairs of paradorsal setae on segments 3-9 and a single paradorsal seta on segment 2, combined with conspicuous groove-like muscular scars in the subdorsal and ventromedial position on segments 1-10 and a reticulate pattern of cuticular wrinkles in ventrolateral areas on segments 2-10. Pycnophyes lageria sp. nov. is distinguished by its ornamented anterior margin of segment 1, resembling candle wax drops; and its depressed cuticular areas on the ventral region of segment 10, combined with the presence of sensory spots similar to Nanaloricus flosculi, and without middorsal structures or middorsal or paradorsal setae. For the first time, this study presents a detailed description and mapping of the introvert in a species of Pycnophyes based on SEM data, which is compared with the information available on the phylum.