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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Iotonchus

Iotonchus (Cobb, 1916) Altherr, 1950

ref. ID; 1726

Dorsal tooth small to medium sized. Subventral teeth absent. (ref. ID; 1726)

ref. ID; 1923

Teeth not retrorse. (ref. ID; 1923)

ref. ID; 5938

Definition

Buccal cavity generally barrel shaped, dorsal tooth located midway to nearly basal in cavity, apex directed anteriorly. Subventral teeth absent. Esophagointestinal junction tuberculate. Female didelphic or monodelphic, ovaries or ovary reflexed. Tails of both sexes similar, narrow and elongated or short and conical. Caudal glands and terminal duct present in most species. Males described for more than half known species. (ref. ID; 5938)

Type species

Iotonchus gymnolaimus (Cobb, 1893) Andrassy, 1958 (ref. ID; 5938)

Nominal species

41. (ref. ID; 5938)
  1. Iotonchus acuticaudatus Eroshenko, 1975 (ref. ID; 1726)
  2. Iotonchus acuticaudus Mulvey & Jensen, 1967 (ref. ID; 1726)
  3. Iotonchus acutus (Cobb, 1917) Andrassy, 1958 (ref. ID; 1726)
  4. Iotonchus ainostomos Buangsuwon & Jensen, 1966 (ref. ID; 1726)
  5. Iotonchus amphigonicus (Thorne, 1924) Andrassy, 1958 (ref. ID; 1726)
  6. Iotonchus antedontoides Coetzee, 1967 (ref. ID; 1726)
  7. Iotonchus antedontus Mulvey, 1963 (ref. ID; 1726)
  8. Iotonchus arenicola Altherr, 1963 (ref. ID; 1726)
  9. Iotonchus baqrii Jairajpuri, 1969 (ref. ID; 1726)
  10. Iotonchus basidontus Clark, 1960 (ref. ID; 1726)
  11. Iotonchus brachylaimus (Cobb, 1917) Andrassy, 1958 (ref. ID; 1726)
  12. Iotonchus chantaburensis Buangsuwon & Jensen, 1966 (ref. ID; 1726)
  13. Iotonchus clarki Mulvey & Jensen, 1967 (ref. ID; 1726)
  14. Iotonchus cobbi Eroshenko, 1975 (ref. ID; 1726)
  15. Iotonchus consimilis (Cobb, 1917) Andrassy, 1958 (ref. ID; 1726)
  16. Iotonchus coomansi Baqri, Baqri & Jairajpuri, 1979 (ref. ID; 1726)
  17. Iotonchus geminus Heyns & Lgerwey, 1965 (ref. ID; 1726)
  18. Iotonchus gymnolaimus (Cobb, 1893) Andrassy, 1958 (ref. ID; 1726)
  19. Iotonchus indicus Jairajpuri, 1969 (ref. ID; 1726)
  20. Iotonchus jairi (Lordello, 1958) Clark, 1960 (ref. ID; 1726)
  21. Iotonchus laticupulatus Rizzhivin, 1971 (ref. ID; 1726)
  22. Iotonchus longicaudatus Baqri, Baqri & Jairajpuri, 1979 (ref. ID; 1726)
  23. Iotonchus maragnus Clark, 1960 (ref. ID; 1726)
  24. Iotonchus microdontus Thong, 1970 (ref. ID; 1726)
  25. Iotonchus monhystera (Cobb, 1917) Jairajpuri, 1970 (ref. ID; 1726)
  26. Iotonchus monticola Eroshenko, 1975 (ref. ID; 1726)
  27. Iotonchus mucronatus Eroshenko, 1975 (ref. ID; 1726)
  28. Iotonchus nigeriensis Mulvey & Jensen, 1967 (ref. ID; 1726)
  29. Iotonchus ophiocercus Clark, 1960 (ref. ID; 1726)
  30. Iotonchus paraamphigonicus Eroshenko, 1975 (ref. ID; 1726)
  31. Iotonchus parabasidontus Mulvey & Jensen, 1967 (ref. ID; 1726)
  32. Iotonchus parazschokkei (Allgen, 1929) Andrassy, 1958 (ref. ID; 1726)
  33. Iotonchus pauli Heyns & Lagerwey, 1965 (ref. ID; 1726)
  34. Iotonchus percivali Clark, 1960 (ref. ID; 1726)
  35. Iotonchus rayongensis Buangsuwon & Jensen, 1966 (ref. ID; 1726)
  36. Iotonchus rinae Coetzee, 1967 (ref. ID; 1726)
  37. Iotonchus risoceiae (Carvalho, 1955) Andrassy, 1958 (ref. ID; 1726)
  38. Iotonchus shafii Khan & Jairajpuri, 1980 (ref. ID; 1726 original paper)
  39. Iotonchus simmenensis (Kreis, 1924) Andrassy, 1958 (ref. ID; 1726)
  40. Iotonchus spinicaudatus Coetzee, 1967 (ref. ID; 1726)
  41. Iotonchus stockdilli Yeates, 1987 (ref. ID; 1775)
  42. Iotonchus tarjani Mulvey & Jensen, 1967 (ref. ID; 1726)
  43. Iotonchus tenuidentatus (Kreis, 1924) Mulvey, 1963 (ref. ID; 1726)
  44. Iotonchus thailandensis Buangsuwon & Jensen, 1966 (ref. ID; 1726)
  45. Iotonchus transkiensis Heyns & Lagerwey, 1965 (ref. ID; 1726)
  46. Iotonchus trichurus (Cobb, 1917) Andrassy, 1958 (ref. ID; 1726)
  47. Iotonchus vorax (Cobb, 1917) Mulvey, 1963 (ref. ID; 1726)
  48. Iotonchus vulvapapillatus Andrassy, 1964 (ref. ID; 1726)
  49. Iotonchus zschokkei (Menzel, 1913) Altherr, 1955 (ref. ID; 1726)

Iotonchus basidontus Clark, 1960 (ref. ID; 1726)

Descriptions

This species found soil around roots. (ref. ID; 1726)

Iotonchus indicus Jairajpuri, 1969 (ref. ID; 1726)

Descriptions

This species soil around roots of Ricinus communis L. and Psidium guajava L. (ref. ID; 1726)

Iotonchus jairi (Lordello, 1958) Clark, 1960 (ref. ID; 1726)

Descriptions

This species found around roots of grasses (unidentified) and Litchi chinensis L. (ref. ID; 1726)

Iotonchus monhystera (Cobb, 1917) Jairajpuri, 1970 (ref. ID; 1726)

Diagnosis

I. monhystera closely resembles I. antedontoides Coetzee, 1967. The only difference is the presence of a minute tooth-like projection in front of and opposite the dorsal tooth in I. antedontoides. Jairajpuri suggested I. antedontoides is synonymy I. monhystera (ref. ID; 1726)

Descriptions

This species found soil around roots of coconut, Cocos nucifera L. (ref. ID; 1726)

Iotonchus parabasidontus Mulvey & Jensen, 1967 (ref. ID; 1726)

Descriptions

This species found soil around roots of banana, Musa paradisiaca L. (ref. ID; 1726)

Iotonchus risoceiae (Carvalho, 1955) Andrassy, 1958 (ref. ID; 1726)

Descriptions

This species found soil around roots of banana, Musa paradisiaca L. (ref. ID; 1726)
  • Female: Body slightly arcuate upon fixation. Cuticle 2-5 µm thick at different places on body. Lateral chords 1/3rd body-width wide near midbody. Lip region set off, 47-59 µm wide and 16-24 µm high. Amphids 5-6 µm wide at 16-20 µm from anterior end of body and 60-65 µm from base of buccal cavity. Buccal cavity 53-64 µm long, 32-40 µm wide. Dorsal tooth nearly basal. Orifices of oesophageal glands located as follows: dorsal 307-360 µm from anterior end of body, first pair of subventrals 128-152 µm from the orifice of dorsal one, second pair of subventrals 195-208 µm from first pair. Nerve ring at 152-200 µm from anterior end of body. Intestine ten cells in circumference. Rectum 44-50 µm or about one anal body width long. Vulva transverse. Reproductive system amphidelphic, ovaries with eight to twelve oocytes. Sphincter present at oviduct-uterus junction. Spindle-shaped sperms observed in rear part of uterus. Tail 310-408 µm or about six to eight anal body-widths long. Caudal glands well developed, spinneret terminal. (ref. ID; 1726)
  • Male: Not found. (ref. ID; 1726)

    Iotonchus shafii Khan & Jairajpuri, 1980 (ref. ID; 1726 original paper)

    Diagnosis

    Iotonchus shafii n. sp. come close to I. basidontus Clark, 1960 and I. parabasidontus Mulvey & Jensen, 1967 but differs from both in the position of its vulva and in having longer spicules (V=55-60, spicules approx. 90 µm in I. basiodontus and I. parabasidontus). It further differs from I. basidontus in having a shorter tail and well developed accessory pieces (c=6.5-8.6, accessory pieces absent in I. basidontus), and from I. parabasidontus in the absence of vulval papillae and in having a longer gubernaculum (vulval papillae present, gubernaculum 20 µm in I. parabasidontus). (ref. ID; 1726)

    Descriptions

    This species found soil around roots of castor, Ricinus communis L. or mango, Mangifera indica L. (ref. ID; 1726)
  • Female: Body arcuate when fixed. Cuticle 2-6 µm thick. Lateral chords 1/4th-1/3rd body-width wide near midbody. Lip region set off, 47-56 µm wide, 17-24 µm high. En face view hexagonal, six labial papillae in the inner circlet and fourteen in the outer. Amphids 5-8 µm wide, at 16-24 µm from anterior end of body, 48-54 µm from base of buccal cavity. Amphidial chamber well developed followed by a narrow amphidial duct. Buccal cavity 51-54 µm long, 32-36 µm wide. Dorsal tooth basal. Orifices of oesophageal glands located as follows: dorsal 261-296 µm from anterior end of body, first pair of subventrals 109-120 µm from orifice of dorsal one, second pair of subventrals 136-194 µm from the first pair. Nerve ring at 145-170 µm from anterior end of body. Intestine ten cells in circumference. Rectum 28-36 µm or about 2/3rd anal body-width long. Vulva transverse. Reproductive system amphidelphic, ovaries with twelve to sixteen oocytes. Well developed sphincter present at uterus-oviduct junction. Proximal part of uterus filled with spindle-shaped sperms. Tail 225-300 µm or four to six anal body-widths long, conoid slightly flattened at tip. Caudal glands present. (ref. ID; 1726)
  • Male: Body more strongly curved ventrally than in females. Testes containing spermatocytes and spindle-shaped sperms. Four pairs of ejaculatory glands present. Spicules 112-131 µm long medially; gubernaculum 29-33 µm; lateral accessory pieces 18-22 µm long. Twelve to sixteen supplements. Rectum 50-64 µm or about one anal body-width long. Tail 180-272 µm or 3.5-4.5 anal body-widths long. Caudal glands and spinneret present. (ref. ID; 1726)

    Etymology

    The new species is named after Mr. Abdus Shafi from whose farm it was collected. (ref. ID; 1726)

    Iotonchus trichurus (Cobb, 1917) Andrassy, 1958 (ref. ID; 1726)

    Descriptions

    This species soil around roots of Cajanus cajan L., Psidium guajava L., Dalbergia sissoo Roxb., Mangifera indica L., and Citrus sinensis L. (ref. ID; 1726)