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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Acantholaimus

Acantholaimus Allgen, 1933 (ref. ID; 3571)

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

ref. ID; 1901

Marine species. (ref. ID; 1901)

ref. ID; 3571

Type species

Acantholaimus longisetosus Allgen, 1933 (ref. ID; 3571)
  1. Acantholaimus akvavitus Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  2. Acantholaimus arminius Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  3. Acantholaimus calathus Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  4. Acantholaimus elegans Jensen, 1988 (ref. ID; 1901)
  5. Acantholaimus gathumai Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)
  6. Acantholaimus geraerti Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)
  7. Acantholaimus gigantisetosus Vivier, 1985 (ref. ID; 1901)
  8. Acantholaimus heipi Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)
  9. Acantholaimus invaginatum Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)
  10. Acantholaimus iubilus Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  11. Acantholaimus longisetosus Allgen, 1933 (ref. ID; 3571)
  12. Acantholaimus marks Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  13. Acantholaimus megamphis Vivier, 1985 (ref. ID; 1901)
  14. Acantholaimus microdontus Gourbault, 1985 (ref. ID; 1901)
  15. Acantholaimus minutus Vitiello, 1970 (ref. ID; 1901)
  16. Acantholaimus pilosus (Kreis, 1963) Hope & Murphy, 1972 (ref. ID; 3571)
    Syn; Neochromadorina pilosa Kreis, 1963 (ref. ID; 3571)
  17. Acantholaimus polydentatus Gerlach, 1951 (ref. ID; 1901, 3571)
  18. Acantholaimus quintus Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  19. Acantholaimus septimus Gerlach, Shrage & Riemann, 1979 (ref. ID; 1901)
  20. Acantholaimus setosus Vitiello, 1970 (ref. ID; 3571)
  21. Acantholaimus vermeuleni Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)
  22. Acantholaimus verscheldi Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

Acantholaimus elegans Jensen, 1988 (ref. ID; 1901)

Descriptions

  • Female: They are similar to males in general body shape. The reproductive system is amphidelphic with reflexed short ovaries. The uterus is large and may contain an egg and/or spermatozoa. Vulva is simple and vagina is thick walled. (ref. ID; 1901)
  • Male Body is cylindrical, narrow in the anterior half of the pharyngeal region, and gradually increase in width on the posterior half until mid body. Cuticular punctations are very fine. The somatic setae are 8-11 µm long and in four longitudinal rows, that is two sub-dorsal and two sub-ventral positions. The amphids are single spiral, 7-11 µm (64-100% corresponding body diameter) in diameter and located at (partly within the stoma region) 7-12 µm from the anterior end. There maybe four setae before the amphidial and four posterior of it if equal length (9-12 µm) located at sub-dorsal and sub-ventral positions similar to the somatic setae. Inner labial sensilla are inconspicuous and the outer labial are 5 µm long and at the same level as the cephalic ones which are 10-11 µm long. The stoma is long (12-18 µm) surrounded by well developed muscles and it has three (four?) teeth anteriorly and highly sclerotized walls posteriorly. The pharynx is 124-159 µm long, cylindrical with a slight swollen terminal end. Cardia is short (4 µm) but conspicuous. The reproductive system is monorchic with outstretched testis located to the right of the intestine. It has a short germinal zone and large spermatozoa (five or six spermatozoa in the testis). The spicules are 1.2 anal body diameter long. There is a pair of pre-cloacal setae located just before the cloaca. The tail has a conical anterior part and filiform posterior part with several setae of the same length as the somatic one. The most terminal setae is located at 13-15 µm before the end of the tail. (ref. ID; 1901)

    Acantholaimus gathumai Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

    Diagnosis

    Acantholaimus gathumai sp. n. is characterised by punctated cuticle with lateral differentiation (5-7 µm in diameter) of larger dots, long (6-8 µm long) somatic and cephalic (10-15 µm long) setae. A. gathumai sp. n. resembles Acantholaimus arminius Gerlach, Shrage & Riemann, 1979, A. minutus Vitiello, 1970, A. quintus Gerlach, Shrage & Riemann, 1979 and A. geraerti in the shape of the stoma. It differs from A. arminius in the position of the amphids which are located within the stoma region and the body size (body length from the anterior to anus = 1400-1600 µm) in A. arminus. It can be distinguished from A. minutus in that cephalic setae are only 6 µm long compared to 10-15 µm in the new species and somatic setae are very short in A. minutus. A. gathumai sp. n. differs from A. quintus in that A. quintus has at least three teeth in the stoma and several setae at the pharyngeal region. A. gathumai can be distinguished from A. geraerti in the lateral differentiation: A. gathumai has a wider (5-7 µm) lateral differentiation although it is a much thinner species (maximum body diameter 15-19 µm compared to maximum body diameter 29-32 µm and lateral differentiation is 4-7 µm and more conspicuous in A. geraerrti sp. n. (ref. ID; 1901)

    Descriptions

  • Female: They are similar to males in all aspect. The reproductive system is amphidelphic with reflexed ovaries. (ref. ID; 1901)
  • Male: Body is cylindrical, anteriorly it tapers slightly and posteriorly it ends with a filiform tail. Cuticular punctations starts at the anterior most level of the amphids; the dots are arranged in regular transverse rows. Laterally (5-7 µm diameter), the dots are larger than on the dorsal and ventral sides. There are four longitudinal rows of somatic setae (6-8 µm long) that start immediately posterior of the amphids at dorso-lateral and ventro-lateral positions and borders the lateral differentiation area. The amphids are a simple spiral, 5-6 µm in diameter or 45-56% corresponding body diameter located at 8-10 µm from the anterior end. Inner labial sensilla are inconspicuous, the outer are 3 µm long and located at the same level as the cephalic ones which are 10-15 µm (1.5-2.0 head diameter at the level of the cephalic setae) long (in most specimens the anterior sensilla are broken off). Stoma is long (7-8 µm), anterior part has teeth and posterior part has sclerotized walls. The pharyngeal muscles surround most of the stoma. The pharynx is cylindrical, 71-87 µm long and swollen at the terminal end to form a bulb which has several interruptions. Cardia is small. The reproductive system is monorchic with outstretched testis located to the right of the intestine; a short germinal zone and large spermatozoa fill the rest of the testis; the vas deferens is short. The spicules are curved on the proximal end and pointed on the distal end. A pair of pre-cloacal setae is present at 4-5 µm from the cloaca. The tail is conical with a long filiform end. (ref. ID; 1901)

    Etymology

    Name given for Prof. J.M. Gathuma of the University of Nairobi. (ref. ID; 1901)

    Acantholaimus geraerti Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

    Diagnosis

    Acantholaimus geraerti sp. n. is characterised by long cephalic sensilla (15-19 µm), well developed teeth in the stoma, narrow (4-6 µm) and conspicuous lateral differentiation. A. geraerti sp. n. resembles A. gathumai sp. n., A. arminius Gerlach, Shrage & Riemann, 1979 and A. calathus Gerlach, Shrage & Riemann, 1979 in the stoma shape. A. geraerti sp. n. can be distinguished from A. gathumai sp. n. by body size (body length from the anterior to anus 363-423, maximum body diameter 14-19 µm in A. gathumai and body length from the anterior to anus 551-651, maximum body diameter 29-32 µm in A. geraerti) and lateral differentiation which is narrow (4-5 µm wide) and more conspicuous in A. geraerti sp. n. compared to A. gathumai (5-6 µm wide) although A. geraerti is the larger of the two species. It can be distinguished from A. arminius by the position of the amphids which are within the stoma region in A. arminius and the wide lateral differentiation. A. geraerti differs from A. calathus by the absence of longitudinal rows of dots present in the latter. (ref. ID; 1901)

    Descriptions

  • Female: They are similar to males in all aspects. The reproductive system is amphidelphic with reflexed ovaries, anterior branch to the right and the posterior one to the left of the intestine. There is a short germinal zone followed by growth zone which may contain only a single developed ova. The uterus is filled with large sperm cells. The vagina is thick walled and vulva is simple. (ref. ID; 1901)
  • Male: The body is cylindrical, tapers slightly to the anterior end and a filiform tail end. Cuticule is punctated with punctations starting from anterior level of the amphids, the punctations are arranged in transverse rows with lateral differentiation having larger and more conspicuous dots than on the rest of the body; the lateral differentiation is 6 µm at the pharyngeal region and 4-5 µm wide at mid body. Somatic setae are (8-12 µm long) in four longitudinal rows; two in the dorso-lateral and two in the ventro-lateral positions and bordering the lateral differentiation. The amphids are spiral with a single turn located at 8-12 µm from the anterior; they are 6-8 µm in diameter (40-50% corresponding body diameter). The inner labial sensilla are inconspicuous, the outer labial are 5 µm long and at the same level as the cephalic setae which are 15-19 µm long. The stoma is 12-17 µm long and it has three teeth. Pharynx is cylindrical (101-114 µm), and anteriorly surrounds the stoma; posteriorly it is expanded to form the terminal bulb. The cardia is small but prominent. Reproductive system is monorchic with outstretched testis. The spermatozoa are large rectangular in shape and they have large nuclei. Vas deferens is short. The spicules are (1.4-1.7 corresponding body diameter) curved proximally and rounded distally. There is a pair of pre-cloacal setae at 6 µm from the cloaca. (ref. ID; 1901)

    Etymology

    Name given for Prof. E. Geraert of the University of Ghent. (ref. ID; 1901)

    Acantholaimus heipi Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

    Diagnosis

    Acantholaimus heipi sp. n. is characterised by a narrow pharyngeal region; long (11-13 µm) cephalic setae, long stoma with three teeth, simple spiral amphids located close to the base of the stoma and a long filiform tail. Acantholaimus heipi sp. n. is similar to A. elegans Jensen, 1988 in body length (total body length: 540-720 µm), position of the amphids and the stoma length. However, A. heipi differs from A. elegans in that all three crowns of anterior sensilla are distinct with the cephalic setae being only 7-8 µm long in A. elegans and 11-13 µm in A. heipi; the posterior part of the pharyngeal region is much wider than the anterior part in A. elegans and it is also a much wider (maximum body diameter 25-30 µm) species compared to A. heipi (maximum body diameter 12-18 µm). (ref. ID; 1901)

    Descriptions

  • Female: They are similar to the male. The reproductive system is amphidelphic with reflexed ovaries. Anterior branch to the right, posterior one to the left of the intestine. (ref. ID; 1901)
  • Male: Body is cylindrical and narrow on the first half of the pharyngeal region, with a slight increase in width towards the end of the pharyngeal region and the tail has a short conical anterior part and a long filiform end. Head region (6-7 µm in diameter) is continuos with the rest of the body. Cuticular punctations are indistinct. Somatic setae (3-5 µm long) are in four longitudinal rows: two dorso-lateral and two ventro-lateral rows. The amphids are spiral with a single turn and the spiral origin can be seen in some specimens; they are (71-100% corresponding body diameter) located at 8-11 µm from the anterior end (anterior most part of the amphids are at the level of the base of the stoma or posterior to it). Inner labial sensilla are indistinct, outer labial short (3 µm long) and the cephalic ones are long (11-13 µm long) and close to the anterior end. The stoma is long (8-11 µm) and it has three protrusible teeth at the anterior part and sclerotized walls in the posterior part. Pharyngeal muscles surround the stoma. Pharynx (92-124 µm long) is cylindrical with a slight expansion and several interruptions of the muscular part at the base. Cardia short (4 µm) but prominent. The reproductive system is long with a short germinal zone posterior of which are large spermatozoa filled with a large nuclei. Vas deferens is short. Spicules are 1.2-1.5 anal body diameter and typical Acantholaimid in shape. A pair of sub-ventral pre-cloacal setae are found at 1-2 µm from the cloaca. Tail is long (184-299 µm) and slightly swollen at the end and tip is pointed. (ref. ID; 1901)

    Etymology

    Named for Prof. Heip of the University of Ghent. (ref. ID; 1901)

    Acantholaimus invaginatum Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

    Diagnosis

    Acantholaimus invaginatum sp. n. is characterised by cuticle with lateral differentiation of larger dots, long cephalic (16-21 µm) and somatic (7-13 µm) setae. Circular amphids (38-64% corresponding body diameter) located close to the anterior end. Long stoma, with three teeth and often invaginated. A. invaginatum resembles A. maks Gerlach, Shrage & Riemann, 1979 in the anterior region (invaginated stoma) and the arrangement of the somatic setae at the pharyngeal region; it resembles A. polydentatus Gerlach, 1951 and A. calathus Gerlach, Shrage & Riemann, 1979 in the size of the cephalic setae and the arrangement of the somatic setae and A. quintus Gerlach, Shrage & Riemann, 1979 in the arrangement of the somatic setae and the well developed teeth in the stoma. A. invaginatum sp. n. differs from A. maks in the absence of a pair of post amphidial setae on either side of the amphids and the length of the somatic setae which are rather short in A. maks. It differs from A. polydentatus and A. calathus in the absence of two longitudinal rows of larger dots on the lateral sides which are present in these two species, and from A. quintus in the length of the cephalic setae: 11 µm or 0.6x(head diameter) at the level of the cephalic setae sensu Gerlach et al., 1979, 15 µm sensu Gourbault & Vincx, 1985 and 8-11 µm or 0.8x(head diameter) at the level of the cephalic setae sensu Vivier, 1985. (ref. ID; 1901)

    Descriptions

  • Female: They are similar to the males in most aspects. Reproductive system is amphidelphic with reflexed ovaries, anterior to the right, posterior to the left of the intestines. Vulva is simple and vagina is 6-7 µm long and thick walled. (ref. ID; 1901)
  • Male: Body is cylindrical, anterior end is blunt and posterior end has a long filiform tail. Cuticle is punctated from the anterior level of the amphids. Punctations are in regular transverse rows. Laterally, they are larger than on the dorsal and ventral sides. The lateral differentiation region is 10-12 µm on the pharyngeal region and mid-body, and 8 µm at the anterior tail region. Somatic setae (7-12 µm long at pharyngeal and 9-13 µm at tail region) are in four longitudinal rows: two in dorso-lateral and two in ventro-lateral positions. Amphids are circular, 5-8 µm (38-66% corresponding body diameter) in diameter and located at 3-5 µm from the anterior end (NB the locations of the amphids from the anterior maybe more than what is measured here when the stoma is not invaginated). Cephalic setae are long (16-21 µm or 1.3-1.4 head diameter at the level of the cephalic setae). Stoma (20-22 µm long) has 3(4?) teeth and often it is invaginated. Pharynx is cylindrical (84-106 µm long), anteriorly surrounds the stoma and posteriorly it is swollen to form the terminal bulb. The reproductive system is monorchic with an anteriorly outstretched testis located to the right of the intestine. The spermatozoa are large rectangular in shape or elongate. Vas deferens is short. The spicules are curved, 1.2-1.7x(anal body diameter) long. Tail is short conical (35-54 µm long) and long posterior filiform part. (ref. ID; 1901)

    Acantholaimus vermeuleni Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

    Diagnosis

    Acantholaimus vermeuleni sp. n. is characterised by a narrow anterior end; short (3-6 µm long) cephalic sensilla located at the small level as the outer labial ones which are half as long as the former; amphids (80-100% corresponding body diameter) that are single spiral with distinct spiral origin and two post-amphidial setae located on the dorso-lateral position at 14-18 µm from the anterior end. A. vermeuleni sp. n. resembles A. akvavitus Gerlach, Shrage & Riemann, 1979, A. gigantisetosus Vivier, 1985, A. iubilus Gerlach, Shrage & Riemann, 1979, A. maks Gerlach, Shrage & Riemann, 1979, A. megamphis Vivier, 1985, A. microdontus Gourbault, 1985, A. minutus Vitiello, 1970, and A. septimus Gerlach, Shrage & Riemann, 1979 in having two post amphidial setae on the dorso-lateral position. A. vermeuleni however differs from all these nematodes, in that they have one or two extra post-amphidial setae on the ventro-lateral position as well and also in having well developed teeth in the stoma which are lacking in the former. A. microdontus differs from A. vermeuleni in size (body length from the anterior to anus 760-1105 µm and maximum body diameter 35-50 µm in A. microdontus compared to body length from the anterior to anus 200-400 µm and maximum body diameter 9-19 µm A. vermeuleni. (ref. ID; 1901)

    Descriptions

  • Female: They are similar to males. The reproductive system is amphidelphic with reflexed ovaries; they have a short germinal zone, developing oocytes, and uterus is partially filled with spermatozoa. The vulva and vagina are simple. (ref. ID; 1901)
  • Male: Body is cylindrical with tapering anterior end and a long filiform tail. The head region is rather small. Cuticular punctations are very fine. There are four rows of somatic setae in dorso-lateral and ventro-lateral positions. They are more conspicuous at the pharyngeal and tail region than on the rest of the body. The amphids are a simple spiral, 4-6 µm diameter (83-100% corresponding body diameter) located at 3-5 µm from the anterior end. These are two short post-amphidial setae located on the dorso-lateral side at 14-18 µm from the anterior. Anterior sensilla are located close to the anterior end; inner labial setae are indistinct, outer labial are half as long as the cephalic sensilla which are 3-6 µm and located at the same level. The stoma is narrow, without distinct teeth. The pharynx is cylindrical (66-90 µm long), with a slightly swollen posterior end to form a bulb. Cardia is distinct. The reproductive system is monorchic with outstretched testis; there is a short germinal zone and large spermatozoa with large nucleus. The vas deferens is short. Spicules are 1.2-1.5 anal body diameter long, flat on the distal end and blunt on the proximal end. There is a pair of pre-cloacal setae at 6-7 µm in front of the cloaca. The tail is conical anteriorly (35-45 µm long) and measures 100-349 µm. (ref. ID; 1901)

    Etymology

    Named for Yvette Vermeulen, coordinator of the Kenya-Belgian Project for the period 1991-1993. (ref. ID; 1901)

    Acantholaimus verscheldi Muthumbi & Vincx, 1997 (ref. ID; 1901 original paper)

    Diagnosis

    A. verscheldi sp. n. is characterised by a narrow elongate anterior pharyngeal region, short outer labial sensilla at the same level as the cephalic setae that are 4-7 µm long. A. verscheldi sp. n. resembles Acantholaimus elegans Jensen, 1988 in body length, stoma and the position of the amphid. It also resembles Acantholaimus heipi sp. n. and A. septimus Gerlach, Shrage & Riemann, 1979 in the stoma. It differs from A. elegans in the shape of the posterior pharyngeal region which is more enlarged posteriorly in A. elegans than in A. verscheldi. A. verscheldi differs from A. heipi in the length of the anterior sensilla (labial sensilla are indistinct and the cephalic ones are 11-13 µm long in A. heipi). It differs from A. septimus in the position of the amphids which are within the stoma region, the presence of two post-amphidial setae on either side of the amphids in the A. septimus and the body size (body length from the anterior to anus 575-850 and maximum body diameter 21-23 µm in A. septimus compared to body length from the anterior to anus 280-467 µm and maximum body diameter 12-21 µm in A. verscheldi sp. n. (ref. ID; 1901)

    Descriptions

  • Female: They are similar to the males in general shape and size. The reproductive system is amphidelphic with reflexed ovaries. The anterior branch is to the right and the posterior one to the left of the intestines. There are large spermatozoa in the uterus. Vulva and vagina are simple. (ref. ID; 1901)
  • Male: Body cylindrical, narrow anterior pharyngeal region with a slight increase in width posteriorly, and the tail is filiform. Cuticular punctations are indistinct. Somatic setae are in four longitudinal rows, that is, two dorso-lateral and two ventro-lateral. Amphids are 4-7 µm in diameter (71-100% corresponding body diameter), spiral with a single turn and they are located (posterior of the base of the stoma) at 11-15 µm from the anterior end. Inner labial sensilla are inconspicuous, outer labial are short 2-3 µm long at the same level as the cephalic setae. The cephalic setae are 4-7 µm long and close to the anterior. The stoma is long (9-13 µm), and it has three teeth anteriorly and highly sclerotized walls posteriorly. The pharynx is cylindrical with some interruptions in the muscular part at the posterior part of the pharynx but no well formed terminal bulb. Cardia is short but prominent. The reproductive system is monorchic with outstretched testis filled with large spermatozoa. The vas deferens is short The spicules are 1.0-1.3 anal body diameter long. There is a pair of pre-cloacal setae at 7 µm anterior of the cloaca. The tail (115-210 µm long) is conical with a long filiform posterior end. (ref. ID; 1901)

    Etymology

    Named for Dominick Vershelde of the University of Ghent. (ref. ID; 1901)