Rhabdostyla dubia Foissner 1979

Souza, Pedro Mendes De, Rossi, Mariana Fonseca & Dias, Roberto Júnio Pedroso, 2024, Systematic review of the genera Rhabdostyla Kent 1880 and Orborhabdostyla Foissner et al. 2010 (Ciliophora, Peritrichia, Epistylididae), Zootaxa 5399 (3), pp. 201-230 : 215

Rhabdostyla dubia Foissner 1979

— Fig. 2 , O

Diagnosis: Size about 30–35µm. Body from a vessel-like form to a funnel-like, when contracted assumes a pear shape with a bifurcated peristomial disc with clear transverse striations on the pellicle. Peduncle measures 2–5 µm, with transverse striations and grooves, usually enlarged at the base. Contractile vacuole found just below the peristomial collar, on the ventral wall of the, wide and quite short, vestibule. Horseshoe-shaped macronucleus, inclined longitudinally. Ciliary of the adoral spiral long and robust. Cytoplasm with large and slightly yellowish granules. Silverline pattern resembles that of Pseudocarchesium erlangensis . Found on ostracods.

Remarks: diagnosis based on ( Foissner 1979b). He reports for the species cysts with about 30 µm in diameter, ectocysts with numerous mole-shaped elevations. The author also highlights that the position of the contractile vacuole and the form of contraction are the characteristics that distinguish R. dubia from other very similar species, R. ovum Kent, 1882 , R. cyclopis Kahl, 1935 and R. ovum var. culiciidarum Nenninger, 1948 . According to him, it is possible that these 4 species are just an expression of the great variability of a species, especially if we assume that Kahl (1935) and Nenninger (1948) wrongly drew the contractile vacuole on the dorsal wall of the infundibulum.

Figures

FIGURE 2. Schematic drawing of representatives of the Rhabdostyla genus. K: Rhabdostyla conipes; L: Rhabdostyla cyclopis, M: Rhabdostyla cylindrica; N: Rhabdostyla dixae; O: Rhabdostyla dubia; P: Rhabdostyla ephemerae; Q: Rhabdostyla fromentellii; R: Rhabdostyla globularis; S: Rhabdostyla hungarica.