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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Sphenomonas

Sphenomonas Stein, 1878 (ref. ID; 4950)
  1. Sphenomonas australis Playfair (ref. ID; 4950)
  2. Sphenomonas australis var. elliptica Playfair (ref. ID; 4950)
  3. Sphenomonas australis var. rhomboidea Playfair (ref. ID; 4950)
  4. Sphenomonas decemlineata Seckt (ref. ID; 4950)
  5. Sphenomonas elongata Lackey, 1962 (ref. ID; 3090 original paper)
  6. Sphenomonas excavata Playfair (ref. ID; 4950)
  7. Sphenomonas laevis Skuja (ref. ID; 3090, 4950)
  8. Sphenomonas mirabilis Playfair (ref. ID; 4950)
  9. Sphenomonas quadrangularis Stein (ref. ID; 3517, 4950)
  10. Sphenomonas quadrangularis var. cruciformis Playfair (ref. ID; 4950)
  11. Sphenomonas spiralis Playfair
    See; Heteronema spirale (ref. ID; 4950)
  12. Sphenomonas teres (Stein) Klebs (ref. ID; 3090, 3517, 4950)
    Syn; Atractonema teres Stein (ref. ID; 4950); Clostenema sociale Stokes (ref. ID; 4950)
  13. Sphenomonas teres var. pyriformis Playfair (ref. ID; 4950)
  14. Sphenomonas triquetra Playfair (ref. ID; 3090, 4950)
  15. Sphenomonas triquetra var. cuneata Playfair (ref. ID; 4950)

Sphenomonas elongata Lackey, 1962 (ref. ID; 3090 original paper)

Descriptions

The cell is elongate usually slightly flexed, rigid and frequently somewhat clubshaped toward the posterior end. In median cross section it may show three weak keels or lobes, gradually rounding posteriorly. In longitudinal section it is somewhat concave-convex or with a median groove at the anterior end. Its shape is rather constant, and is distinctly different from S. laevis Skuja, S. teres (Stein) Klebs, or S. triquetra Playfair. The pellicle is smooth without striations and is thick. There is a slight overhang at the anterior end, so that the mouth opening is oblique and circular. It cannot be called subterminal. The nucleus is median, lying close to one edge. Usually it is an elongate oval, granular and with or without endosomes. Its membrane is well defined. The cytoplasm is finely vacuolated and contains inclusions of two to three type. One to several large paramylum granules may be present. Their shape not constant; oval disks, irregular disks and concave-convex discs occur addition there are spheres which strongly resembles fats and all spherules, quite refractive, which are common. A typical vacuole opens into the gullet reservoir. This is deep, sometimes as much as 10 um, the reservoir being expanded to a blublike shape. The two flagella emerging from its floor are quite tenuous, and the short trailing flagellum, never more than one sixth body length, usually lies closely along the body and is seen with difficulty. The anterior flagellum, which shows very little, if any, tapering, is irregular in its movements, not vibratile at the tip. It is about one half body length. (ref. ID; 3090)

Type locality

It has been taken from depths of 60 feet in San Diego Bay. There is no record of it from any fresh water location we have examined. Its occurrence indicates it as primarily a marine sand dweller. (ref. ID; 3090)