Table 3 in Long distance dispersal and pseudo-cryptic species in Gastrotricha: first description of a new species (Chaetonotida, Chaetonotidae, Polymerurus) from an oceanic island with volcanic rocks

Table 3 (continued on next page). Comparison of several morphological structures among different species of Polymerurus Remane, 1927 belonging to the ‘spined scales’ morphotype.
CharacteristicsP. insularis sp. nov.P. nodicaudusP. entziiP. nodifurcaP. paraelongatumP. ringueletiBody shapeElongatedElongatedElongatedElongatedElongatedElongatedTotal length215–408 µm330–544 µm350–420 µm395 µm504 µm290 µmPharynx constrictionSlightly evidentSlightly evidentSlightly evidentSlightly evidentSlightly evidentSlightly evidentFurca base constrictionAccentuatedAccentuatedAccentuatedAccentuatedSlightly accentuatedAccentuatedPharynxCylindrical shape, gradative enlargement towards the rear endCylindricalNo descriptionCylindricalNo descriptionSlightly evident posterior enlargementGeneral structure of scalesSpined, no peduncle Spined, no peduncleSpined, no peduncleSpined, no peduncleSpined, no peduncleSpined, no peduncleGeneral shape of scalesPentagonal, anteriorly curved Anteriorly rounded, as a dome and distally posterior end shaped incised, or all-rounded and as an U smallerAnterior and lateral extremities with concave shapeNo descriptionAnteriorly rounded, posterior extremity V-shapedNo descriptionSpinesPresentPresentPresentPresentPresentPresentShape of dorsal spinesStraight, usually long, shorter Short and simple, near the head larger posteriorlyNo descriptionShort, simpleSimpleNo descriptionFurcaShaped as a U, middle furrow V-shaped, no furrow V-shapedShaped as a wider U, middle furrow presentNo descriptionV-shapedU-shapedVentral scales at furca basePolygonal or rounded, no peduncle nor superpositionNo descriptionNo descriptionNo descriptionNo descriptionNo descriptionDorsal scales at furca baseSpineless, mostly pentagonal, a few visibly by SEM oval or rounded, larger and flatNot describedNot describedNot describedNot describedNot describedInternal pair of small spines at ventral furca basePresentNot describedNot describedAbsentNot describedNot described