Ptygura noodti ( Koste, 1972 ) Koste, 1972

Meksuwan, Phuripong, Pholpunthin, Pornsilp & Segers, Hendrik, 2011, Diversity of sessile rotifers (Gnesiotrocha, Monogononta, Rotifera) in Thale Noi Lake, Thailand, Zootaxa 2997, pp. 1-18 : 15-17

Ptygura noodti ( Koste, 1972) new combination

( Figs 8–9 )

Synonym: Floscularia noodti Koste, 1972: 534 –540

Comments. We identified our material as being conspecific with Floscularia noodti Koste, 1972 based on complete concordance of the tube and of the morphology of the contracted body and trophi of the specimens with Koste’s (1972) description, notwithstanding the incompleteness of the original description. Our examination of living specimens reveals that this species does not belong to Floscularia Cuvier, 1798 but, rather, to Ptygura Ehrenberg, 1832 . Indeed, the corona of the species is bilobed and more or less elliptical, as in Ptygura , not four-lobed as in Floscularia . Koste (1972) based his description of the species exclusively on preserved, contracted material, and allocated the animal to Floscularia based on a superficial similarity of the tube it inhabits with that of species of the F. ringens group, in particular, F. janus . The generic assignment of the specimens we observed is unequivocal, given the present generic diagnosis in family Flosculariidae . Actually, its tube morphology is not unique in Ptygura : also Ptygura pilula (Cubitt, 1872) inhabits a tube constructed of loose pellets of mucus and detritus, albeit that in the latter species these pellets are round, not elongate.

Redescription. Body fusiform. Foot clearly separated from trunk, foot peduncle short. Corona distinctly bilobed, ventral sinus distinct, dorsal gap wide, width about 1/5 of corona width. Buccal area with distinct rounded projection near the ventral margin, bearing a cluster of fairly long relatively stiff cilia, these are moved up and down nervously. A single dorsal projection protecting the dorsal antenna (“Nackenhäckchen” of Koste 1972, 1978) present; this projection is composed of two fairly equal, adjacent elements: a ventral, spherical one and a smaller, blunt-triangular dorsal one. Lateral antenna long and slender. Tube consist of elongate, rather ill-defined lumps of strongly elongated gelatinous material in which some detritus material is embedded; these are arranged horizontally, radiating outward from the central cavity inhabited by the animal. Trophi malleoramate, symmetrical. Three proximal unci teeth on both sides slightly reinforced; left – right 18–16 unci teeth in total.

Measurements. Female total height ca. 410 µm. Trunk length ca. 130–150 µm, width ca. 60 µm. Foot stalk length ca. 13 µm. Corona height ca. 75–90 µm, width ca. 100–150 µm. Length of buccal setae cluster ca. 55 µm. Length of lateral antenna ca. 75–100 µm. Tube length ca. 250–370 µm.

Figures

FIGURE 8. Ptygura noodti (Koste, 1972) n. comb. 8 a: adult female; 8 b: contracted specimen, apical region showing the dorsal projections. Scale bars: 8 a = 100 µm; 8 b = 50 µm.

FIGURE 9. Ptygura noodti (Koste, 1972) n. comb.: 9 a – 9 b: tube structure in different specimens; 9 c: Trophi SEM photograph, frontal view. Scale bars: 9 a – 9 b = 100 µm; 9 c = 5 µm.