 
 
Spirotrichea: 
Oligotrichia: Oligotrichida: Halteriidae
Strombidium caudatum
Fromentel, 1874
|  Genus: Paratene makes nearly closed circle around body; ventral kinety often present 
(Illustrated Guide, 1985). Ovoid to spherical; adoral zone very conspicuous two to four conspicuous sickle-form frontal 
membranellae, adoral membranellae extend down cytopharynx; no body bristles or cirri 
(Kudo, 1966).  
Body conical, ovoid or elongate posteriorly; somatic cilia absent; AZM composed of large membranelles 
which emerge from the peristome and encircle the apex of the cell; polysaccharide plates or platelets 
may conver and strengthen the posterior portion of the body (Carey, 1992).
 Species: 
Cell body ovoid, transparent, posterior end drawn out to form a caudal projection, 
32 μm long 
(An Illustrated Guide to Freshwater Zooplankton in Japan, 2000).
 | 
Similar Genus -> >  Halteria
Strombidium . caudatum Fromentel, 1874 (or S. calkinsi 1902 ?), 
cell body 35 μm long, 14 μm wide, 
membranelles about 8 μm long, 
x 400, x 640, Shiro-numa, Tatebayashi city, Gunma Pref., Japan, June 2001 by Y. Tsukii
 50 μm
 50 μm
 100 μm
 100 μm
 150 μm; x 400 :
 150 μm; x 400 : 
 31 μm
 31 μm
 63 μm
 63 μm
 94 μm; x 640
 94 μm; x 640
 
 
 
Strombidium sulcatum 
Claparède and Lachmann, 1858: 
Ovoid, 60 μm long; 
anterior bluntly pointed; AZM extends 1/3 the body length; posterior rounded; 
the region of cortical platelets from the equatorial cleft to posterior end; a band of trichites presents 
in this region (Carey, 1992). 
Strombidium viridae Stein, 1867 (Syn. Strombidium nasutum Smith, 1897): 
Conical, with a well-developed peristomial collar; rounded posterior; 
80 μm long; 
bundles of trichites make an equatorial band; posterior covered with polygonal cortical platelets; 
macronucleus vermiform (Carey, 1992).  
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