Ref ID : 1113
Walter Guhl; Opercularia coarctata, a variable peritrich. Arch.Protistenk 121:308-346, 1979
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1. Since the first description of Opercularia coarctata by Claparede and Lachmann 1854 this peritrich has been described with 28 different names 2. The zooids of Opercularia coarctata very variable. All individual have constant numbers of circular galleires of cilis; 11/4-11/2. The cilis are 8-12 um long. The c.v. mostly is found in the lower region of the buccal cave, during the contraction of the animal the peristomial region formes a snout, while the basal part overreaches the peduncle 3. Apart from these constant signs the zooids are to be found in 5 ecoforms. In ecoform I-III the peristom is not or little protrudent, while in ecoform IV and V the peristom protrudes evidently. These are intermediate forms between all ecoforms. In all ecoforms: Length: 36-124 um, Width: 16-48 um 4. In Opercularia coarctata the shape of the macronucleus is not constant, all forms of "Langkerne" (macronuclues horseshoe-formed) are possible 5. As "Verbreitungsstadien" (propagative forms) you may find zooids, which swim only with the adoral ciliary circle. But mostly typical swarmers are formed with aboral ciliary circle, though the disc is not always retracted 6. In worse milieu Opercularia coarctata forms "Kurz-Dauer-Stadien" (short-time permanent forms). By further deterioration this peritrich formes regular thin or thick cysts 7. The different shapes of zooids depend on oscillation of oxygen 8. Opercularia coarctata is a direct indicator for a rich occurrence of bacteria and only an indirect indicator for saprobity 9. Because of the existence of a "Peristomialfurche" (peristomial groove) Opercularia coarctata is a real Opercularia. You can look upon Opercularia coarctata as a link between Epistylis and Opercularia.