a-s Photomicrographs of Heterogastrostyla salina nov. spec. from life (a–e) and after protargol staining (f–s). a–d Different body shapes, arrowhead in (a) indicates the contractile vacuole. e Cytoplasm containing numerous lipid droplets and refractive crystals. f Showing the spindle-shaped extrusomes (arrows) after protargol staining. g Ventral view of the holotype specimen. h, i Ventral view to show the frontoventral ciliature, arrow depicts the additional frontoventral cirri. j, k Ventral view to show the postoral ventral ciliature, arrow indicates the additional postoral ventral cirri. l, n–p, r Development ventral development in the proter, arrow in (l) and arrowhead in (r) indicate the anlage for the right marginal row; arrow in (n) depicts the small patch of densely distributed kinetids posterior to the frontoventral anlage I; arrows in (p) and (r) denote the dorsomarginal anlage (dikinetidal row) that originates from the anterior of the right marginal anlage. m, q Development fronto-ventral-transverse anlagen in the opisthe. s Dorsal view of a late divider, arrowheads show the caudal cirri. Scale bars = 30 μm (a–e).