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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Propomponema

Propomponema Ott, 1972 (ref. ID; 3571)

Chromadorida Filipjev, 1929: Family Cyatholaimidae Filipjev, 1918: Subfamily Pomponematinae Subfam. nov. (ref. ID; 3571)

ref. ID; 3571

Type species

Propomponema foeticolum Ott, 1972 (ref. ID; 3571)
  1. Propomponema foeticolum Ott, 1972 (ref. ID; 3571, 6573)
  2. Propomponema websteri Sharma & Vincx, 1982 (ref. ID; 6573 original paper)

Propomponema websteri Sharma & Vincx, 1982 (ref. ID; 6573 original paper)

Differential diagnosis

Propomponema websteri sp. nov. is distiguished by the long filiform tail, the cuticular ornamentation consisting of rows of fine punctations alternating with rows of larger punctation, by the distally broadened gubernaculum, and two outstretched testes. It resembles Propomponema foeticolum Ott, 1972, the only species of this genus till now, by the lack of the lateral differentiations (except on the tail), the shape of the precloacal supplements, the big but simple spicules, and the gubernaculum with lateral flanges. However, P. websetri is clearly distinguished from P. foeticolum; the latter has a lower a ratio (43-61), a different cuticular structure, a shorter tail, blunt teeth on the gubernaculum, and two opposing testes. One of the characters defining the genus Propomponema is "the alternating rows of dots and the slit-like markings" (Ott 1972) which are also found in Pomponema effilatum Boucher, 1976. However, the latter species is set apart by its different gubernaculum shape. (ref. ID; 6573)

Descriptions

  • Male: General body shape long, very slendier with long filiform tail. Cuticle with annulated appearance: two rows of coarse punctations with three rows of finer punctations in between. In caudal region, this pattern is replaced by regular punctations and one longitudinal row of coarser punctations in the lateral field. A few LMP's in the cervical and caudal region. Head with six small internal labial papillae (1.5 µm); six external labial setae (4 µm) arranged in one circle with the four cephalic setae (2 µm). Four cervical setae in submedian position. Amphids spiral with five and a half turns in ventral direction; 9 µm diameter i.e., 58% of cbd. Buccal cavity small, cyathiform and slightly sclerotized with a small dorsal tooth. Two smaller ventrosublateral teeth. Pharynx cylindrical with enlarged base, without distinct bulb. Cardia not distinct. Lumen of pharynx does not continue straight into lumen of intestine, but is slightly bent dorsally. Nerve ring at 52% of pharyngeal length. Ventral pore behind nerve ring; vetral cell not clear. Reproductive system diorchic; both testes outstretched anteriorly, located on right side of intestine. Sperm cells globular (8-12 µm). Spicules 42 µm long; gubernaculum 24 µm long with distal end enlarged; both spicules and gubernaculum well sclerotized. Thirteen to 15 precloacal supplements, evenly spaced (10 µm); composed of two pair subsurface elements, placed one below the other. Five to seven cuticular rods between supplements as well as immediately anterior and posterior to first and last supplement. The most posterior supplement is located at 25 µm from the cloacal opening, the most anterior at 215 µm. One medioventral seta occurs at 10 µm from the cloacal opening. Tail long, slender with conoid part less than one-fifth of tail length; 12 times cloacal diameter. Three caudal glands with the two posterior ones more clearly defined. (ref. ID; 6573)
  • Female: Only characters distinguishing it from male are mentioned. Amphids 6 µm in diameter, i.e., 41% of cbd. Annulated appearance of female not apparent in the single specimen available. Reproductive system didelphic, amphidelphic with reflexed ovaries, both located on left side of intestine. Filiform portion of tail longer than in male; 18 times anal diameter. (ref. ID; 6573)
  • Juvenile: Juveniles not examined. (ref. ID; 6573)

    Type locality

    Belcarra Park, British Columbia, Canada. (ref. ID; 6573)

    Examined materials

    Four males, one female. (ref. ID; 6573)

    Deposited slide

    Slide No.367 contains (male 1); slide No.368 contains (female 1). Slide No.377 contains (male 2) and slide No.378 contains (male 3). (ref. ID; 6573)