Main Content
< Top page

The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Raritobrilus

Raritobrilus Tsalolichin, 1981 (ref. ID; 7912)

Order Enoplida: Family Tobrilidae (ref. ID; 7912)

ref. ID; 7912

Diagnosis

Cuticle thin ringed of visually smooth. Biocrystals in the body cavity present or absent. Stoma with two overlapping pockets; one onchium in each pocket. Buccal cavity goblet like. Female sexual system differentiated. Vagina rather wide, with developed muscles. Vulva positioned equatorially or preequatorially. Seminal ductus long, rather thick; seminal ejaculatory canal with distinct muscles. Spicules of very characteristic shape, relatively short and wide, elongated-triangular. Their proximal end wide, distal end split in two, proximal process shorter and slightly distant. Supplements, in number of 5-7, always divided in two groups 2 + (3-5), between which free space exists (the presence of "zero-supplement"). In majority species, the first from cloaca and the last or preceding the last (with the presence of seven supplements) are smaller. Supplements have peculiar shape: large, urchinlike, shoulders well developed. Glandular ductus dilated only at the exit out of the supplement. Tail long and slender; subterminal seta either present or absent. (ref. ID; 7912)

Remarks

Raritobrilus Tsalolichin, 1981 includes three species, which, I believe, are united by their common morphological characters. The structure of the supplementary apparatus in males of R. steineri (Micoletzky, 1925) and R. scallensis (Schneider, 1925) makes them close to species of Eutobrilus, which are included in the grandipapillatus group. In R. allophysis (Steiner, 1919), males are not yet known. The structure of the mouth apparatus in females (anterior pocket of the stoma very weakly separated from the buccal cavity, it is almost fused with it) conforms to the diagnosis of Epitobrilus, to which the species is transferred. Therefore Epitobrilus, after the revision, includes six vaild species: E. meyli (Tsalolichin, 1981), E. setosus (Altherr, 1963), E. flagellatus (Andrassy, 1963), E. parvipapillatus (Kreis, 1932), E. medius (Schneider, 1916), and E. allophysis (Steiner, 1919), and Raritobrilus includes 13 species, 11 of which are from the gandipapillus group of Eutobrilus. Diagnosis of the genus is modified. (ref. ID; 7912)

Type species

Raritobrilus steineri (Mikoletzky, 1925) (ref. ID; 7912)
  1. Raritobrilus affectiosus (Shoshin, 1988) (ref. ID; 7912)
  2. Raritobrilus altherri (Altherr, 1953) (ref. ID; 7912)
  3. Raritobrilus andrassy (Altherr, 1963) (ref. ID; 7912)
  4. Raritobrilus anguiculus (Tsalolichin, 1977) (ref. ID; 7912)
  5. Raritobrilus antarcticus (Tsalolichin, 1981) (ref. ID; 7912)
  6. Raritobrilus assimulatus (Shoshin, 1988) (ref. ID; 7912)
  7. Raritobrilus delamarei (Altherr, 1963) (ref. ID; 7912)
  8. Raritobrilus fortis (Tsalolichin, 1972) (ref. ID; 7912)
  9. Raritobrilus grandipapillatus (Brakenhoff, 1914) (ref. ID; 7912)
  10. Raritobrilus husmanni (Altherr, 1958) (ref. ID; 7912)
  11. Raritobrilus scallensis (Schneider, 1925) (ref. ID; 7912)
  12. Raritobrilus selengaensis (Tsalolichin, 1977) (ref. ID; 7912)
  13. Raritobrilus steineri (Mikoletzky, 1925) (ref. ID; 7912)

Raritobrilus antarcticus (Tsalolichin, 1981) (ref. ID; 7912)

Descriptions

Slender small size worms. Head end rounded; vestibulum tall. Width of head in females 27 µm, in male 23 µm. Head setae large. Length of longest head setae in females 18 µm (65-67 percent of head width), in male, 15 µm; short setae length 8-10 µm. Buccal cavity goblet shape, its width 10-12 µm, depth 20-23 µm. Pockets of stoma wide, well pronounced, overlapping, onchia large. Length of esophagus in females, 360-400 µm; in male, 380 µm. Male has 5 same-size supplements. Size of supplements 12-16x12-18 µm. Empty space between second and third supplements present ("zero-supplement"). Length of supplementary row 278 µm. Spicules wide, weakly curved. Length of tail in females 160 and 165 µm, in male 135 µm. Subterminal seta absent. (ref. ID; 7912)

Comments

Individuals found in Lake Taimyr differ from type specimens in smaller body size (specimens from Antarctic: (male, male) L=1.64-1.83 mm, (female, female) L=1.62-2.00 mm), longer head setae (Antarctic specimens have longer head setae, 8-11 or 50 percent of head width) and slightly larger spicule (in Antarctic specimens, spicule 39-42). (ref. ID; 7912)

Examined materials

One male and 2 (female, female) from Lake Taimyr, Savich Island, depth 7 m, 24.VIII.1988, Male: L=1460 µm, a=3.84, c'=3.87, spic.- 50, suppl.- 5.2. Female: L=1280 and 1441 µm, a=16.64 and 20.87, b=3.59 and 3.64, c=8.06 and 8.73, V=51.29 and 52.50 percent, c'=4.42 and 4.78. (ref. ID; 7912)

Type specimens

Type specimens are deposited in the collection of the Laboratory of Biology and Systematics of Aquatic Invertebrates of the Institute of Biology of Inland Water Bodies of the Academy of Sicences of the USSR, Borsk. (ref. ID; 7912)