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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Pterodrilus

Pterodrilus Moore, 1895 (ref. ID; 1923)

Family Cambarincolidae (ref. ID; 6651)

ref. ID; 1923

Without setae; with posterior sucker; pharynx with dorsal and ventral chitinous jaws; commensal on crayfish. With two pairs of testes in segments 5 and 6. Body with appendages. Appendages in the form of blunt cylindrical projections along the median dorsal line of body. (ref. ID; 1923)
  1. Pterodrilus alcicornus Moore, 1895 (ref. ID; 1923)
  2. Pterodrilus annulatus (ref. ID; 6466)
  3. Pterodrilus distichus Moore, 1895 (ref. ID; 1923)
  4. Pterodrilus durbini Ellis, 1919 (ref. ID; 1923)
  5. Pterodrilus hobbsi (ref. ID; 6466)
  6. Pterodrilus mexicanus Ellis, 1919 (ref. ID; 1923) or 1920 (ref. ID; 6651)

Pterodrilus alcicornus Moore, 1895 (ref. ID; 1923)

Descriptions

Dorsal appendages on segments 3, 4, 5, and 8. (ref. ID; 1923)

Pterodrilus annulatus (ref. ID; 6466)

Descriptions

The acrosome is short. The acrosome tube is laterally bent in the anteriormost region and is slightly twisted, with an external helical ridge around the posterior. The acrosome vesicle protrudes slightly through the anterior opening of the tube and is covered by the plasma membrane, which supports the apical corona. Electron-dense material is located in the anterior portion of the vesicle. The vesicle extends posteriorly and terminates in a thickened ring surrounded by the limen. A basal invagination passing through the ring extends to the anterior portion of the acrosome to form the subacrosomal space. The material in the space is amorphous. A short acrosome rod is located in the space and surrounded by the basal vesicular ring. The nucleus has a slight helical twist with a shallow depression in both anterior and posterior surfaces. A shortish midpiece has the central tubules of the axoneme penetrating about a quarter of the way between the mitochondria. The flagellum has a prominent central-sheath axoneme and a wide helical marginal fiber coiled around it. The fiber is noticeable, as it is twice the usual width of the fibers. A short electron-dense cylinder is located around the base of the flagellum and the fiber starts some distance from the dense cylinder. There is a dense perforated plate at the flagellar base, and an end piece is present. (ref. ID; 6466)

Pterodrilus distichus Moore, 1895 (ref. ID; 1923)

Descriptions

Dorsal appendages on segments 2 to 8 inclusive. (ref. ID; 1923)

Pterodrilus durbini Ellis, 1919 (ref. ID; 1923)

Descriptions

Segments 7 and 8 with funnel-shaped enlargements of the dorsal portions; funnel of 8 excavated dorsally so its dorsal margin bears two small "horns". (ref. ID; 1923)

Pterodrilus hobbsi (ref. ID; 6466)

Descriptions

The acrosome is short. The acrosome tube is twisted, with an external helical ridge along the crest, making 2 gyres. The posterior end of the tube is slightly thickened to form a limen. The protrusion of the acrosome vesicle through the anterior opening of the tube varies from a slight rounding to a conical projection. The covering plasma membrane has a short apical corona. The anterior vesicle with the rounded end has some electron-dense body material located in the apical region. An ovoid electron-dense body is located subterminally in the terminal conical forms and in some rounded forms. The vesicle passes posteriorly and ends in a thickened ring beyond the limen. The basal invagination passes through the ring and extends to the anterior portion of the acrosome to form the subacrosomal space. The space is filled with amorphous, moderately electron-dense material, but no visible rod. The nucleus, midpiece, and flagellum are very similar to that described above for P. annulatus except for a difference in the width of the helical marginal fiber. (ref. ID; 6466)

Pterodrilus mexicanus Ellis, 1919 (ref. ID; 1923) or 1920 (ref. ID; 6651)

Descriptions

Dorsal appendages on segment 8 only; a simple, 4-horned appendage. (ref. ID; 1923)