Main Content
< Top page

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Macroposthonia

Family Criconematidae (ref. ID; 5849, 6740)
  1. Macroposthonia bakeri (Wu, 1965) DeGrisse & Loof, 1965 (ref. ID; 5838)
    Syn; Criconemoides kanaliei Khan, 1971 (ref. ID; 5838)
  2. Macroposthonia brevistyla (Singh & Khera, 1975) comb. n. (ref. ID; 5838 redescribed paper)
    Syn; Criconemoides brevistylus Singh & Khear, 1975 (ref. ID; 5838)
  3. Macroposthonia canadensis Ebsary, 1981 (ref. ID; 5849 original paper)
    See; Criconemella canadensis (ref. ID; 5832)
  4. Macroposthonia coomansi DeGrisse, 1967
    See; Criconemella tescorum (ref. ID; 5832)
  5. Macroposthonia curvata (Raski, 1952) DeGrisse & Loof, 1965 (ref. ID; 5838)
    Syn; Criconemoides dorsoflexus Boonduang & Ratanaprapa, 1974 (ref. ID; 5838)
  6. Macroposthonia hlagum Van den Berg, 1979
    See; Lobocriconema hlagum (ref. ID; 5958)
  7. Macroposthonia onoensis (ref. ID; 5838)
  8. Macroposthonia palustris (ref. ID; 5849)
  9. Macroposthonia parareedi Ebsary, 1981 (ref. ID; 5849 original paper)
  10. Macroposthonia reedi (ref. ID; 5849)
  11. Macroposthonia rotundicauda (DeGrisse, 1969) (ref. ID; 5838)
  12. Macroposthonia rotundicaudata (Loof, 1964) DeGrisse & Loof, 1965 (ref. ID; 5838)
    Syn; Criconemoides parakouensis Germani & Luc, 1976 (ref. ID; 5838)
  13. Macroposthonia sphaerocephaloides (DeGrisse, 1967) Orton Williams, 1981
    See; Criconemella sphaerocephaloides (ref. ID; 5832)
  14. Macroposthonia tescorum (DeGuiran, 1963) DeGrisse & Loof, 1965
    See; Criconemella tescorum (ref. ID; 5832)

Macroposthonia bakeri (Wu, 1965) DeGrisse & Loof, 1965 (ref. ID; 5838)

Synonym

Criconemoides kanaliei Khan, 1971 (ref. ID; 5838)

Notes

The two species of C. kamaliei were stated to be closely related to M. bakeri differing from this species by the anteriorly directed dorsal body annules, number of annules (80 vs. 70-79) and slight anastomosis (also slight in M. bakeri). Other measurements of stylet lengths (102-112 µm for both species), vulval position (10 vs. 8-10), and tail shapes overlap. Based on similarities between the two species, dorsal body annule structure is judged insufficient to constitute specific distinction and C. kamaliei is synonymized with M. bakeri. (ref. ID; 5838)

Macroposthonia brevistyla (Singh & Khera, 1975) comb. n. (ref. ID; 5838 redescribed paper)

Synonym

Criconemoides brevistylus Singh & Khear, 1975 (ref. ID; 5838)

Notes

The diagnosis of C. brevistylus indicated that it was most similar to C. annulatus; however, four distinct submedian lobes are present and the vulva is open requiring its placement in Macroposthonia. Within Macroposthonia this species is most closely related to M. onoensis from which it is differentiated by the greater number of annules (140-156 vs. 111-136), longer stylet (50-60 vs. 40-51 µm), and more posterior excretory pore (35-41 vs. 29-36). (ref. ID; 5838)

Macroposthonia canadensis Ebsary, 1981 (ref. ID; 5849 original paper)

See

Criconemella canadensis (ref. ID; 5832)

Descriptions

Body tapers slightly anteriorly. Head of four annules, truncated in profile, continuous with body, not set off. First head annule thin and narrow. Pseudolips and submedian lobes absent. Oral disc prominent, amphids and mouth obscure under SEM. Stylet rigid less than 20% of body length. Stylet knobs about 6 µm wide, anterior surfaces indented. Body annules 126(121-136), strongly retrorse, 2.5-3.0 µm thick, margin distinctly crenate. Anastomoses about 10. Number of annules from head to base of stylet 21-26, esophagnus 31-38, excretory pore 35-43. Vulva 13(11-15) annules from terminus, vulva lips simple, open, protruding slightly beyond body contour. Vagina straight, oblique to body axis. Anus not observed. Tail conical, terminus cup-like with internal lobes or complexities. VL/VB 1.4(1.1-1.6). Spermatheca small without sperm. (ref. ID; 5849)
  • Juveniles: Unknown. (ref. ID; 5849)
  • Males: Unknown. (ref. ID; 5849)

    Notes

    Macroposthonia canadensis n. sp. is closely related to M. onoensis and M. palustris but differs from both in the absence of submedian lobes (onoensis has separate submedian lobes, palustris has dorsally and ventrally fused lobes), crenate cuticle (smooth in onoensis and palustris), and more posterior excretory pore (35-43 annules vs. 32-36 annules in onoensis and palustris). Macroposthonia canadensis is similar to palustris in having the cup-like tail terminus with internal complexities but differs from onoensis with its lobed terminus. (ref. ID; 5849)

    Type host and locality

    Specimens were collected October 1979 by Mr. R. Sewell and Mr. C. Granger from native grass in a sand substrate along the Ottawa River near Crystal Bay, Ontario. (ref. ID; 5849)

    Type designations

    Holotype (female), slide No.250 in the Canadian National Collection of Nematodes in Ottawa: Paratypes (eight females) on slides 250a-250h deposited as follows: six females in the Canadian National Collection of Nematodes in Ottawa, one female each at the United States Department of Agriculture Nematode Collection, Beltsville, Maryland, and the University of Califoria Nematode Survey Collection at Davis, California. (ref. ID; 5849)

    Measurements

  • Holotype (female): L=0.35 mm, a=10.5, b=4.4, c=8.3, V=88, St=48 µm. (ref. ID; 5849)
  • Paratypes (eight females): L=0.34(0.30-0.38) mm, a=10.9(8.4-12), b=5.2(4.2-5.5), c=8.8(7.8-9.3), V=88.6(87-89), St=48(45-49) µm. (ref. ID; 5849)

    Macroposthonia curvata (Raski, 1952) DeGrisse & Loof, 1965 (ref. ID; 5838)

    Synonym

    Criconemoides dorsoflexus Boonduang & Ratanaprapa, 1974 (ref. ID; 5838)

    Notes

    Criconemoides dorsoflexus was considered distinctive because of the dorsally curved body; however, stylet lengths (47-48 vs. 47-68 µm), vulval position (7 vs. 5-10), number of annules (86-88 vs. 78-101), and head and tail shapes indicate strong similarity with M. curvata. The same authors also described two specimens of M. curvata which had measurements similar to C. dorsoflexus. The only character separating C. dorsoflexus from M. curvata, the dorsal body curvature, is not considered sufficient to justify specific distinction and therefore C. dorsoflexus is assinged as above. (ref. ID; 5838)

    Macroposthonia parareedi Ebsary, 1981 (ref. ID; 5849 original paper)

    Descriptions

    Body tapers slightly anteriorly. Head of three annules, truncated in profile, continuous with body, not set off. Submedian lobes small, obscure in lateral view. Oral disc low, amphids laterad of oral disc. Labial plates present or absent, small. Stylet rigid, about 13% of body length. Stylet knobs 9.5-11 µm wide, anterior surfaces indented. Body annules 117(111-121) retrorse, about 4 µm thick, margins smooth. Anastomoses absent or few, not exceeding four. Number of annules from head to base of stylet 18-21, esophagus 29-33, excretory pore 31-34. Vulva 12 or 13 annules from terminus. Vulva open, lips elongated, retrorse, anterior lip with two spines. Vagina sigmoid. Anus three to five annules from terminus. Tail conical, terminus pointed. VL/VB 1.4(1.3-1.6). Spermatheca present without sperm. (ref. ID; 5849)
  • Juvenile female (fourth stage): N=2; L=0.40-0.41 mm, a=10.2-11.2, b=3.8-4.1, St=52-54 µm, R=121-123. Similar to female but with irregular to finely crenate body annules and a less conical tail. (ref. ID; 5849)
  • Male: Unknown. (ref. ID; 5849)

    Notes

    Macroposthonia parareedi n. sp. is most similar to M. reedi but differs in having more body annules (111-121 vs. 104-112), a more anterior vulva (12-13 annules vs. 9-10 annules from terminus), a more posterior excretory pore (31-34 annules vs. 26-29 annules from head) and a longer stylet (59-66 µm vs. 51-62 µm). (ref. ID; 5849)

    Type host and locality

    Specimens were collected by Mr. R. Sewell, June 1979, from wild rice at the Jock River, 20 km south of Ottawa. (ref. ID; 5849)

    Type designations

    Holotype (female), slide No.249 in the Canadian National Collection of Nematodes, Ottawa. Paratypes, seven females, two juveniles on slides 249a-249i deposited as follows: five females, two juveniles in the Canadian National Collection of Nematodes, Ottawa; one female each at the United States Department of Agriculture Nematode Collection, Beltsville, Maryland, and the University of California Nematode Survey Collection at Davis, California. (ref. ID; 5849)

    Measurements

  • Holotype (female): L=0.41 mm, a=9.6, b=4.1, c=8.8, V=88.6, St=62 µm. (ref. ID; 5849)
  • Paratypes (seven females): L=0.45(0.38-0.48) mm, a=9.8(8.5-10.8), b=4.4(3.8-4.7), c=9.5(8.1-10.6), V=89(88-90.5), St=62(59-66) µm. (ref. ID; 5849)

    Macroposthonia rotundicaudata (Loof, 1964) DeGrisse & Loof, 1965 (ref. ID; 5838)

    Synonym

    Criconemoides parakouensis Germani & Luc, 1976 (ref. ID; 5838)

    Notes

    Criconemoides parakouensis has four distinct, separate submedian lobes and open vulva indicating its inclusion in Macroposthonia. This species keys to M. rotundicauda (DeGrisse, 1969) with which stylet lengths (52-61 vs. 50-60 µm), vulval (4-5 vs. 5-7), and excretory positions (16-20 vs. 18-22) overlap. Head, tail, and anterior vulval lip structures in both species are also similar indicating conspecificity. (ref. ID; 5838)