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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Paramonohystera

Paramonohystera Steiner, 1916 (ref. ID; 3571)

Monhysterida Filipjev, 1929: Family Monhysteridae De Man, 1876: Subfamily Monhysterinae De Man, 1876 (ref. ID; 3571)

Monohysteridae (ref. ID; 7627)

ref. ID; 3571

Type species

Monhystera (Paramonohystera) megacephala Steiner, 1916 (ref. ID; 3571)
  1. Paramonohystera (Paramonohystera) biforma Wieser, 1956 (ref. ID; 3571) reported author and year? (ref. ID; 7627)
  2. Paramonohystera canicula Wieser & Hopper, 1967
    See; Metadesmolaimus caniculus (ref. ID; 3571)
  3. Paramonohystera (Leptogastrella) elliptica Filipjev, 1918 (ref. ID; 3571)
    Syn; Paramonohystera setosa Filipjev, 1918 (ref. ID; 3571)
  4. Paramonohystera (Paramonohystera) longicaudata Timm, 1963 (ref. ID; 3571)
  5. Paramonohystera (Paramonohystera) megacephala (Steiner, 1916) (ref. ID; 3571)
    Syn; Monhystera (Paramonohystera) megacephala Steiner, 1916 (ref. ID; 3571)
  6. Paramonohystera (Paramonohystera) micramphis Stekhoven, 1950 (ref. ID; 3571)
  7. Paramonohystera mystacoderma Wieser, 1960 (ref. ID; 3571)
  8. Paramonohystera (Leptogastrella) paranormandica (Micoletzky, 1922) (ref. ID; 3571)
    Syn; Monhystera (Theristus) paranormandica Micoletzky, 1922 (ref. ID; 3571)
  9. Paramonohystera (Leptogastrella) pellucida (Cobb, 1920) Wieser, 1956 (ref. ID; 3571) reported author and year? (ref. ID; 7627)
  10. Paramonohystera (Paramonohystera) proteus Wieser, 1956 (ref. ID; 3571)
  11. Paramonohystera setosa Filipjev, 1918
    See; Paramonohystera (Leptogastrella) elliptica (ref. ID; 3571)
  12. Paramonohystera (Leptogastrella) stricta (Gerlach, 1956) Wieser, 1956 (ref. ID; 3571)
  13. Paramonohystera (Leptogastrella) tschislenkoi Platonova, 1971 (ref. ID; 3571)
  14. Paramonohystera wieseri Ott, 1977 (ref. ID; 7627 original paper)
    Syn; Paramonohystera n. sp. (Wieser et al., 1974) (ref. ID; 7627)

Paramonohystera wieseri Ott, 1977 (ref. ID; 7627 original paper)

Synonym

Paramonohystera n. sp. (Wieser et al., 1974) (ref. ID; 7627)

Descriptions

Body very slender, cylindrical almost throughout its length, head diameter 29-30 µm in males, 33-35 µm in females, diameter at level of amphids 35-37 µm in males, 40-45 µm in females, this is also already the maximum body diameter, anal body diameter 34-40 µm. Cuticle very faintly annulated (seen in living specimen only), devoid of somatic setae except for some 3-5 µm long bristles in the cervical region and two subventral rows of 2-4 µm long bristles on the male tail. Hypodermis with a conspicuos dark reddish brown to almost black pigmentation throughout the body, which however can only be seen in freshly extracted live specimens and vanishes upon exposure to oxidized sea water and fixation (for ecophysiological data on the species see Wieser et al. 1974). Beneath the hypodermis the plasmatic parts of the muscle cells are conspicous feature. They are spindle shaped, 40-100 µm long and arranged in single file below the fibrous part of each of the four muscle fields. They are strongly vacuolated and in TEM sections appear packed with electron dense storage material (glycogen?). Head with a circle of setiform labial papillae, 10-12 µm long, which are closely followed by a circle of 10 strong cephalic setae, the sublateral ones in pairs, 47-50 and 38-42 µm long in males, 50-58 and 40-46 µm in females, which amounts to 1.4-1.8 and 1.1-1.4 head diameters in both sexes. The lateral setae are single, their length is intermediate between the longer and shorter sublateral setae. There are always 4 submedian cervical setae on the level of the anterior margin of the amphid. Amphids circular, very faint in preserved animals, in living animals however very conspicous, because of the lack of pigment in the region of the amphid. Diameter of amphid 17.5-22 µm (52-61% of corresponding body diameter) in males, 12-14 µm (29-35% of c.b.d.) in females, anterior margin 20-27 µm from anterior end. Stoma with strong cuticular ring, esophagus cylindrical, slightly swollen at anterior end, 275-330 µm long; slender conical cardia, 20 µm long. The large nerve ring encircles the esophagus at about 50% of its length; there is always a ventral gland, about 60 µm long, its anterior end 20-30 µm behind the end of the esophagus. Excretory pore seen in one male only on the level of the anterior margin of the amphid. Tail conical, the last 2/5 cylindrical with slightly swollen tip, 182-200 µm (5.2-5.4 anal body diameters) in males, 230-280 µm (6.6-7 a.b.d) in females; opening of spinneret terminal. Three terminal setae, 32-37 µm long. (ref. ID; 7627)
  • Male: Males with slender, only slightly curved spicula, 40-46 µm (1.1-1.3 anal body diameters) long, cephalate proximally. Gubernaculum small, faint, probably tubular. There is a lateral projection near the tip of the spiculum, which I think belongs to the latter structure. Wieser (1956) however figures a lateral tooth in smiliar position for the gubernaculum in P. biforma and P. pellucida. There are 31-34 elliptical ventral subcuticular structures preanally, the first 370-450 µm, the last about 20 µm in front of the anus, which appear to lie in cuticular bumps when the anal region is curved ventrally. Testes could not be distingushed with certainity. (ref. ID; 7627)
  • Female: Female with single outstretched gonade beginning at 45-50% of body length vulva at 64-65% of body length. The female gonade is relatively short compared with the size of the animal. It should be noted, that in most females the gonades seemed not to be fully developed. (ref. ID; 7627)

    Remarks

    Paramonohystera wieseri n. sp. differs from all other species of the same genus by the length of both the labial papillae and cephalic setae, and the scarcity of somatic setae. According to Wieser 1956 the long labial papillae would put this species into the genus Promonhystera Wieser, 1956, it does however not very well agree with other diagnostic charaters given for the latter genus, especially the male genital apparatus. P. mutila Lorenzen, 1973 has similar elongated labial papillae and some other features in common with the new species: the strong development of the esophagus at its beginning, the terminal setae and the shape of the spicula, which are however greatly reduced in P. mutila. The latter species demonstrates the heterogeneity of the genus Paramonohystera, - which contains species with vastly differing characters, especially regarding the male copulatory apparatus - because the differential diagnostic character of the subgenera P. sensu stricto and Leptogastrella, namely the number of cephalic setae, appear in P. mutila as sexual dimorphism (Lorenzen 1973). (ref. ID; 7627)

    Examined material

  • Holotype (male): U.S.N.M. Nr.53993 L=2.57 mm, a=58.4, b=8.2, c=13.2. (ref. ID; 7627)
  • Paratypes (male): U.S.N.M. Nr.53994-53996 L=2.31-2.65 mm, a=52.3-58.9, b=7.7-8.8, c=11.9-13.8. (ref. ID; 7627)
  • Paratypes (female): U.S.N.M. Nr.53997-53999 L=2.614-3.040 mm, a=49.6-60.8, b=8.0-9.6, c=10.7-11.4. (ref. ID; 7627)