Homalozoon vermiculare (STOKES,1887) STOKES,1890 seen here preying on a peritrich ciliate. The characteristic dense aggregate of granules can be seen. This is displaced by the ingested prey and then disperses as the food vacuole proceeds distally. From freshwater pond near Boise, Idaho. Brightfield This image was taken by William Bourland. He now uses a Zeiss Axioskop 2 with Spot Insight and Spot Flex CCD cameras (Diagnostic Instruments). Image copyright: William Bourland, image used under license to MBL (micro*scope).
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Freshwater and Terrestrial Microbes of Idaho (USA) and Elsewhere
|Description of Homalozoon vermiculare: Homalozoon vermiculare (Stokes,1887) Stokes,1890
Homalozoon vermiculare is a large, bottom-dwelling, carnivorous ciliate found in standing fresh water.Body 150-1500 um long; vermiform,laterally compressed, Anterior end slightly expanded as dsistinct rounded oral bulge packed with thin rod-shaped extrusomes;posterior end tapered to broadly rounded. Single moniliform macronucleus,about 25 micronuclei. 5-21 contractile vacuoles along dorsal side.4 types of extrusomes, 2 types of small subpellicular mucocysts and long (~5-15 um) and short (~2 um) thin rod-shaped extrusomes in the oral bulge, short extrusomes also scattered in cytoplasm.Prominent aggregation of refractile granules in cytoplasm posterior to oral bulge (parapharyngeal mass);composed of two types of granules,one composed of paraglycogen,he second type is comprised of concentric lamellae and is rich in magnesium, phosphorus, potassium, and calcium;function of parapharyngeal mass remains unknown.Somatic ciliature consists of 10-20 right longitudinal kineties with ~10 um cilia, 3-4 left kineties with 1-2 um bristles, anterior ends of these kineties bear clavate cilia comprising the dorsal brush.Circumoral kinety separate from somatic kineties.