Described by Schewiakoff under the name Trichorhynchus tuamotuensis.
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From the collection
Images from Schewiakoff, 1896
|Description of Mycterothrix tuamotuensis: Ciliate, size 25-50 x 25-30 microns, usually about 35-45 x 25-30 microns, recently excysted individuals are smaller. Cylindroid to ellipsoid, anterior end broadly rounded to bluntly pointed. With a protruding hemisphaerical uvula. Macronucleus globular, in cell centre, with few to many nucleoli. Micronucleus strongly basophilic, in small indentation of macronucleus, chromosomes recognizable during division. Contractile vacuole in distal portion of uvula, during diastole 5-6 microns in diameter, 7-8 pulsations/min, without collecting canals. Cytopyge on terminal dorsal margin of uvula, near contractile vacuole. Cytoplasm rapidly moving, yellowish due to numerous strongly refractive, refractile granules concentrated in the uvula. Feeds on bacteria which are digested in about 4 microns sized, compact, food vacuoles concentrated in central portion of cell. Lorica cylindrical, very fragile, colourless; bacteria, algae, detritus and carmine grains may adhere exteriorly; stains with mucicarmine and fuchsine and persists long after desertion. length 1.5-2 times that of ciliate. During case construction, which occurs "very rapidly", the ciliate rotates before anchoring itself to the substrate or case by the anterior tuft of cilia. The ciliate protrudes from the case by about 1/4 of its body length. On disturbance it either withdraws into case or leaves it front end first. Free specimens move jerkily or swim in wide spirals rotating about their longitudinal axis. Somatic infraciliature is not well known. Cilia 5-6 microns long, slightly elongated toward anterior, stiff, arrariged in 7-8 parallel rows coursing obliquely. On dorsal margin of uvula a semicircle of 12 about 15-20 microns long, stiff, obliquely spread caudal cilia which fold down when cell withdraws into case. Anterior ciliary tuft consists of 1-4 fused, 15 microns long cilia. Vestibulum 6-7 microns deep, contains many very active cilia. |