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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Fridericia

Fridericia Michaelsen, 1889 (ref. ID; 1257) or 1899 (ref. ID; 3692)

Family Enchytraeidae (ref. ID; 1257, 1928, 6650)

Family Enchytraeidae: Subfamily Achaetinae (ref. ID; 5790)

See Distichopus

ref. ID; 1928

The number of species in this genus, which was 21 in the Tierreich of 1900, has now risen to about 65. As the number of characters on which the species are founded is very small, and these characters themselves do not show a very wide range of structural variation, it follows that the differences between some of the species are every small. For instance, in the group of species distinguished by having two diverticula to the spermatheca, it is extremely difficult to assign a specimen to a particular species. It usually bears an equally close resemblance to several species. In these circumstances, the need for a revision of the genus is very urgent. (ref. ID; 1928)
  1. Fridericia agricola Moore (ref. ID; 1928)
  2. Fridericia alata Niel. & Christ. (ref. ID; 6913)
  3. Fridericia cf. alba Moore, 1895 (ref. ID; 6650)
  4. Fridericia aurita Issel, 1905 (ref. ID; 1257, 1928)
  5. Fridericia bisetosa (Levinsen, 1884) (ref. ID; 1257) or Levins (ref. ID; 1928) reported author and year? (ref. ID; 5790)
  6. Fridericia bretscheri Southern, 1907 (ref. ID; 1257) reported year? (ref. ID; 1928)
  7. Fridericia bulboides Nielsen & Christensen, 1959 (ref. ID; 6650)
  8. Fridericia bulbosa (Rosa, 1887) (ref. ID; 1257, 3692) reported year? (ref. ID; 1928) reported author and year? (ref. ID; 5790)
  9. Fridericia callosa (Eisen, 1878) (ref. ID; 3692)
  10. Fridericia christeri Rota & Healy, 1929 (ref. ID; 6653)
  11. Fridericia connata Bretscher, 1902 (ref. ID; 1257, 1928)
  12. Fridericia deformis Moller, 1971 (ref. ID; 6653)
  13. Fridericia galba (Hoffmeister, 1843) (ref. ID; 1257) reported author and year? (ref. ID; 1928)
    Syn; Fridericia michaelseni Bretscher, 1899 in Southern, 1909 (ref. ID; 1257)
  14. Fridericia glandulosa Southern, 1909 (ref. ID; 1257) reported year? (ref. ID; 1928)
  15. Fridericia gracilis von Bullow, 1957 (ref. ID; 6653)
  16. Fridericia hegemon (Vejdovsky, 1877) (ref. ID; 1257) reported year? (ref. ID; 1928)
  17. Fridericia isseli Rota, 1994 (ref. ID; 6653)
  18. Fridericia jordanensis Bell (ref. ID; 6650)
  19. Fridericia leydigi (Vejdovsky, 1877) (ref. ID; 1257) or 1878 (ref. ID; 6653) reported year? (ref. ID; 1928)
  20. Fridericia lobifera Vejdovsky (ref. ID; 1928)
  21. Fridericia maculata Issel (ref. ID; 6913)
  22. Fridericia magna Friend, 1899 (ref. ID; 1257) reported year? (ref. ID; 1928)
  23. Fridericia michaelseni Bretscher (ref. ID; 1928)
  24. Fridericia minuta Bretscher (ref. ID; 1928)
  25. Fridericia montafonensis Schmelz, 1998 (ref. ID; 6664)
  26. Fridericia multisegmentata Wang, Xie & Lian, 1999 (ref. ID; 6650 original paper)
  27. Fridericia nemoralis Nurminen, 1970 (ref. ID; 6653)
  28. Fridericia nielseni (ref. ID; 5790)
  29. Fridericia paroniana Issel, 1904 (ref. ID; 1257, 1928)
  30. Fridericia perrieri (Vejdovsky, 1877) (ref. ID; 1257) or 1878 (ref. ID; 6653) reported year? (ref. ID; 1928)
  31. Fridericia polychaeta Bretscher, 1900 (ref. ID; 1257) reported year? (ref. ID; 1928)
  32. Fridericia pseudoargentea Knollner, 1935
    See; Marionina southerni (ref. ID; 7204)
  33. Fridericia ratzeli (Eisen, 1872) (ref. ID; 1257) reported year? (ref. ID; 1928)
    Syn; Fridericia lobifera Vejdovsky, 1879 in Southern, 1909 (ref. ID; 1257)
  34. Fridericia ratzeli var. beddardi Bretscher (ref. ID; 1928)
  35. Fridericia renatae (ref. ID; 5790)
  36. Fridericia singula Nielsen & Christensen, 1961 (ref. ID; 6653)
  37. Fridericia striata (Levinsen, 1884) (ref. ID; 1257) or Levins (ref. ID; 1928)
    Syn; Fridericia valdensis Issel, 1905 in Southern, 1909 (ref. ID; 1257)
  38. Fridericia tubulosa Dozsa-Farkas (ref. ID; 6913)
  39. Fridericia ulmicola Friend (ref. ID; 1928)
  40. Fridericia ulrikae Rota & Healy, 1999 (ref. ID; 6653)
  41. Fridericia valdensis Issel (ref. ID; 1928)
  42. Fridericia waldenstroemi Rota & Healy, 1999 (ref. ID; 6653)
  43. Fridericia zykoffi Vejdovsky, 1903 (ref. ID; 3692)

Fridericia cf. alba Moore, 1895 (ref. ID; 6650)

Descriptions

Length 11-12 mm (fixed), 16 mm (living); width 0.3-0.5 mm; segments 52-59. Head pore at 0/I, dorsal pore from VII onwards. Chaetae from II onwards, 2-4 in dorsal and ventral bundle, mostly 4 anteriorly (from II to ca. XXI) and 2 posteriorly; chaetae absent in XII; outer chaetae ca. 62 µm in length, 6 µm in maximum width. Epidermal gland cells transversely arranged, ca. 14 rows per segment (when whole-mounted), more conspicuous in the anteclitellar region. Clitellum over XII-2/3XIII, with gland cells irregularly arranged; medioventral gland cells absent or scant anteriorly and in a small posterior patch. Brain 140 µm long, 50-60 µm wide anteriorly and 90 µm wide posteriorly, anterior rend triangularly convex, and posterior rounded or trancated. Peptonephridia one pair, straight and short, extending to IV or anterior of V, unbranched or with 1-2 twigs. Septal glands with dorsal connection in first and second pairs. Gut dilatation gradual. Dorsal vessel originating in XIX. Chylus cells present in 3 postclitellar segments, e.g. from XIV to XVI, or from XVII to XIX. Chloragogen cells from ca. VII onwards. Nephridia from 6/7 onwards with 4 pairs in front of clitellum, anteseptal parts ca. 1/2 as long as postseptal; efferent ducts originating from anterior of postseptal parts. No copulatory glands enveloping vental nerve cord. Nucleate coelomocytes numerous, oval to round, with regular outline, with grandules evenly distributed and without refractile globules, ca. 20 µm long and 10-20 µm wide; small anucleate corpuscles scarce, 5-7 µm long and ca. 4 µm wide (when whole-mounted). Detached chaetae present in coelome. Sperm funnels cylindrical, ca. 220 µm long and ca. 90 µm wide, with distinct collar as wide as funnel, mostly distorted within preserved. Vasa deferentia irregularly coiled. Penial bulbs one pair, hemispherical, 60 µm long, 36 µm wide, 30 µm in height, opening ventrolaterally at mid XII. One large seminal vesicle in X-XI. No egg sacs, 1-2 eggs present. Spermathecae in V, communicating with dorsolateral region of oesophagus separately. Ampullae onion-shaped, with transversely scattered spermatozoa, 120 µm long, 96-100 µm in maximum wide. Ectal ducts ca. 360 µm long and 26 µm wide, without glands at ectal pore. Ental ducts ca. 100 µm long and 40 µm wide. (ref. ID; 6650)

Remarks

The distinctive characters of F. alba are large size, short peptonephridia and simple spermathecae. In these respects, our specimens are similar to those from the type locality (Philadelphia, USA). However, the original material had chaetae were 2-7 per bundle, mostly 4, the brain slightly emarginate posteriorly, and the dorsal vessel originating in XXII. Male genital organs and nephridia were not described by Moore (1895). (ref. ID; 6650)

Material examined

Five whole mounts and two live specimens from T7, T12, T16. (ref. ID; 6650)

Fridericia bisetosa (Levinsen, 1884) (ref. ID; 1257) or Levins (ref. ID; 1928) reported author and year? (ref. ID; 5790)

Descriptions

The species differs from F. paroniana, in having a larger number of segments, in the different shape of the spermatheca, and in the absence of the large gland at the pore of the spermatheca. (ref. ID; 1928)

Fridericia bretscheri Southern, 1907 (ref. ID; 1257) reported year? (ref. ID; 1928)

Descriptions

The anterior bundles contain 4, rarely 5, setae. The spermatheca has no gland at the base. The brain is not much longer than broad, and the salivary glands are unbranched. (ref. ID; 1928)

Fridericia bulboides Nielsen & Christensen, 1959 (ref. ID; 6650)

Descriptions

Length 6 mm (fixed), 9 mm (living); segments 28-42. Chaetae 2-4 in dorsal and ventral bundle, mostly 4 in the anteclitellar and 2 in postclitellar regions. Epidermal gland cells 5-6 rows per segment. Clitellum over XII-2/3XII, with gland cells irregularly arranged and well developed everywhere. Peptonephridia unbranched and very long, much coiled in IV-V, extending to VI-VII. Dorsal vessel originating in XVII. Chylus cells present in region XIII-XIV. Sperm funnels cylindrical, with tall collar. No seminal vesicles. Spermathecal ampullae onion-shaped, with a large gland at ectal pore. (ref. ID; 6650)

Remarks

The characteristics of our specimens coincide with the original description, except that our specimens have larger glands at spermathecal pore and a more posterior region of dorsal vessel (XIV-XVI). (ref. ID; 6650)

Material examined

Seven whole mounts and two live specimens from T6, T7, T1, T14. (ref. ID; 6650)

Fridericia glandulosa Southern, 1909 (ref. ID; 1257) reported year? (ref. ID; 1928)

Descriptions

The length is 15-25 mm. Setae, 6-8 in the anterior ventral bundles. The epidermis is very glandular, especially near the pores of the spermathecae. The clitellum occupies segments 12 and 1/2+13, and is covered with close-set granular glands. The salivary glands consist of a short thick basal portion, and two long slender branches which may be subdivided at the lip. The dorsal vessel varies greatly in point o of origin. In some specimens it rises in the 17th segment, in others as far back as the 23rd segment. The sperm-funnel is 3-6 times as long as broad. In one specimen, the sperm in the neck of the funnel was bright green in colour. The spermatheca is of a very characteristic shape. It occasionally has glands at the base. (ref. ID; 1928)

Fridericia hegemon (Vejdovsky, 1877) (ref. ID; 1257) reported year? (ref. ID; 1928)

Descriptions

This species has not more than 4 setae in a bundle, and in the duct of the nephridium rising at the front end of the postseptal, instead of the posterior end. The duct of the spermatheca is very long, with a single gland at the base. (ref. ID; 1928)

Fridericia leydigi (Vejdovsky, 1877) (ref. ID; 1257) or 1878 (ref. ID; 6653) reported year? (ref. ID; 1928)

Descriptions

The brain is convex in front, not concave. There are 2-4 setae in the anterior ventral bundles. The length varies from 4 to 10 mm. The dorsal vessel rises in the 15th segment. The salivary glands are entire, or divided into two short branches at the end. (ref. ID; 1928)

Fridericia lobifera Vejdovsky (ref. ID; 1928)

Descriptions

There were three pairs of large copulatory glands in the 13th, 14th, and 15th segments. The dorsal vessel rises in the 19th or 20th segment. The sperm-funnel is about twice as long as broad. It is much broader at the mouth than at the base. The spermatheca has two small unicellular glands at the base. This species appears to be very rare. (ref. ID; 1928)

Fridericia michaelseni Bretscher (ref. ID; 1928)

Descriptions

It is very common in soil, manure, under stones, etc. Southern have previously recorded this species as F. galba (tom. cit.), and an inclined to think that all previous British records of F. galba belong to this species. Southern have not yet found undoubted representatives of the latter species. The two forms are very similar, but F. michaelseni is distinguished apparently from the other species by slight differences in the structure of the brain and nephridia. The British specimens agree with the Danish ones (Ditlevsen, tom. cit.) in having no gland at the distal end of the spermathecal duct, such as Bretscher describes in the Swiss specimens. The funnel is 4-7 times as long as broad; setae 6-7 in a bundle. The cuticle have several rows of dark glands in each segment. The description of F. ulmicola Friend (tom. cit.) is too vague to stand. The possession of three diverticula to the spermatheca would not constitute a specific distinction, as F. michaelseni often shows this character. (ref. ID; 1928)

Fridericia multisegmentata Wang, Xie & Lian, 1999 (ref. ID; 6650 original paper)

Descriptions

Fixed length 20-28 mm (holotype: 27 mm); width 0-7-0.8 mm; segments 73-80 (holotype: 80). Body whitish. Head pore at 0/I, dorsal pores from VII. Chaetae 2-4 in dorsal and ventral bundle, mostly 4 anteriorly (from II to ca. XX) and 2 posteriorly, disposed in pairs; straight, simple-pointed, with ental hook; outer chaetae ca. 101 µm in length, 10 µm in maximum width; chaetae absent in XII. Epidermal gland cells numerous, irregularly arranged. Clitellum over XII-XIII, gland cells irregularly arranged; medioventral gland cells absent in the anterior region (in front of the posterior border of male pores) between male pores. Brain 126 µm long, 100 µm wide anteriorly and 132 µm wide posteriorly, anterior slightly concave and posterior truncated. Peptonephridia arising ventrolaterally, brancihing into 6 and 7 twigs respectively in the anterior and posterior parts, one twig present in the middle part. Septal glands with dorsal connection in first and second pairs; no secondary glands. Gut dilatation gradual. Dorsal vessel originating in XXV-XXVI (holotype: XXVI). Chylus cells from XI to ca. XVII. Chloragogen cells from VII. Nephridia from 6/7 with 5 pairs in front of clitellum, anteseptal parts ca. 1/3 as long as postseptal; efferent ducts originating from terminal regions of postseptal parts. No copulatory glands enveloping ventral nerve cord. Coelomocytes of two types, both oval to round, with regular outline. Nucleate coelomocytes numerous, with granules evenly distributed and with several refractile nucleoli, 30-40 µm long and 22-26 µm wide; small anucleate corpuscles scarce, 7-8 µm long and 6-7 µm wide (when whole-mounted). Sperm funnels cylindrical, 338 µm long and 152 µm wide, with raised collar narrower than funnel. Vasa deferentia confined to XII, irregularly coiled. Penial bulbs one pair, hemspherical, 116-132 µm long, 97-101 µm wide, 77-97 µm in height, opening ventrolaterally at mid XII. One large seminal vesicle in the anterior of XI. No egg sacs. 1-2 eggs present. Spermathecae in V, having conical ampulla and 2 diverticula with almost cylindrical outline and lumen. Spermatozoa scattered throughout the common lumen of ampulla and diverticula. Ampullae ca. 70 µm in length (from connection with ectal duct to beginning of ental duct); paired diverticula 39-43 µm in length (from distal end to connection with ectal duct) and ca. 40 µm in width. Each ampulla communicating with dorsolateral region of oesophagus separately by a short ental duct. Ectal ducts 480-500 µm long and 27 µm wide, without glands at ectal pore. (ref. ID; 6650)

Remarks

The new species differs from all known Fridericia species by the following combination of characters: 1. The large number of segments, 2. a maximum of 4 chaetae in a bundle, 3. spermathecae with 2 diverticula and without glands at ectal pore. Nevertheless, there is some resemblance of Fridericia perrieir (Vejdovsky), Fridericia agricola Moore and Fridericia jordanensis Bell concerning spermathecae and peptonephridia. Besides the different chaetae, segments and sperm funnel, the present species differs from the first two by the morphology of spermathecal lumina and nephridia, and differs from the last by the more posterior origin of the dorsal vessel. (ref. ID; 6650)

Etymology

Named multisegmentata for the large number of segments. (ref. ID; 6650)

Material examined

  • Holotype: Mature, whole mount, collected from Cangjingdian, Mt. Hengshan 1050 m, broad-leaf forest dominated by beech (Fagaceae), yellow-brown soil, April 25, 1991 (T8). (ref. ID; 6650)
  • Paratypes: Eight whole mounts (2 dissected), eight in 10% formalin all from T8. (ref. ID; 6650)

    Fridericia paroniana Issel, 1904 (ref. ID; 1257, 1928)

    Descriptions

    This species resembles closely F. bisetosa. (ref. ID; 1928)

    Fridericia ratzeli (Eisen, 1872) (ref. ID; 1257) reported year? (ref. ID; 1928)

    Synonym

    Fridericia lobifera Vejdovsky, 1879 in Southern, 1909 (ref. ID; 1257)

    Descriptions

    There is considerable uncertainty about the various descriptions of this species. The length varies from 15-20 mm. The anterior ventral bundles contain 6-8 setae. The anterior segments each bear several rows of narrow, irregular, granular glands. The clitellum is formed of close-set glands. The coelomic corpuscles are small and spindle-shaped. The brain is convex before and behind. The salivary glands are freely branched. The spermatheca has a wide duct with several small glands near the pore. The ampulla is half as long as the duct. There are 6-10 fairly regular oval sessile diverticula attached to the ampulla, each by a broad base. The spermatheca evidently varies considerably. It is usually described as having a long, slender duct, small ampulla, with numerous small, irregular sac-shaped diverticula. (ref. ID; 1928)

    Fridericia striata (Levinsen, 1884) (ref. ID; 1257) or Levins (ref. ID; 1928)

    Synonym

    Fridericia valdensis Issel, 1905 in Southern, 1909 (ref. ID; 1257)

    Descriptions

    This species is readily recognized by the shape of the spermatheca, number of setae, etc. The salivary glands are usually only feebly branched, but in specimens from Edinburgh the branching was very copious. (ref. ID; 1928)

    Fridericia valdensis Issel (ref. ID; 1928)

    Descriptions

    This species, recently described by Issel from Italy, has been found in two localities in Co. Wicklow. The Irish specimens agree very close with Issel's description and figures in all points but one. Issel figures the duct of the nephridium as rising from the end of the postseptal, whereas in the Irish specimens it rises just behind the septum. This, however, is a very variable point in the genus. (ref. ID; 1928)