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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Cryptaulax

Cryptaulax Skuja, 1948 (ref. ID; 4898, 4907)

[ref. ID; 4898]
This genus, erected by Skuja (1948), contains several species of often flexible (metabolic?) cells with a spiral groove and a subapical gullet/flagellar pocket associated with two flagella. The genus was originally classified in the cryptomonads (Skuja 1948); however electron-microscopical examination of an organism originally named C. taeniata showed this species to be a kinetoplastid assignable to the genus Rhynchobodo (Vors 1992). Vors (1992) suggested at the remaining species of Cryptaulax might also be kinetoplastids. Ultrastructural examination of a second species has revealed a close similarity with Rhynchobodo however there is no record of a kinetoplast for most nominal species in the genus. (ref. ID; 4898)

[ref. ID; 4907]
Cryptaulax was created for Spiromonas akopos Skuja (1939) for nomenclatural reasons. The genus contains flagellates with an often more or less spirally twisted groove and two heterodynamic flagella; one trailing, and one directed forward. Species added by Skuja (1948, 1956), Throndsen (1969), Larsen & Patterson (1990), and Patterson & Simpson (in press). Some discussion in Vors (1992). The characters used or distinguish between species include: shape and size of cell, length of anterior flagellum, groove morphology, appearance of rostrum, presence or absence of contractile vacuoles, extrusomes, and refractile granules. As with other difficult taxa, there is considerable overlap of characters. Vors (1992) performed light and electron microscopy on Cryptaulax taeniata Skuja, 1956, which turned out to be a polykinetoplastid and assigned this species to Rhynchobodo Lackey 1940. Vors (pers. com.) concluded that the "strap-shaped-laterally compressed" cell shape ascribed to this species by Skuja (1956) was due to a misinterpretation of his observations. The figures of Skuja (1956, tab.61: 6-8) do not show compressed organisms, however, cells with well developed longitudinal grooves may be misinterpreted as flattened. Vors (1992) has suggested that all Cryptaulax species may be assignable to the kinetoplastids. (ref. ID; 4907)
  1. Cryptaulax akopos (ref. ID; 4907)
  2. Cryptaulax conoidea (ref. ID; 4907)
  3. Cryptaulax elegans (ref. ID; 4907)
  4. Cryptaulax formica (ref. ID; 4907)
  5. Cryptaulax longiciliatus (ref. ID; 4907)
  6. Cryptaulax marina (ref. ID; 4907)
  7. Cryptaulax thiophila (ref. ID; 4907)
  8. Cryptaulax vulgaris Skuja, 1948 (ref. ID; 4898, 4907)

Cryptaulax vulgaris Skuja, 1948 (ref. ID; 4898, 4907)

Descriptions

Cells plastic, usually cylindrical, but may adopt a shorter, more ovoid, outline. Two heterodynamic flagella arise from a flagellar pocket located about one third of cell length from anterior end. Anterior flagellum of about cell length, posterior flagellum about two times cell length, part of it trails in a twisted groove which takes a spiral path of about one turn starting at flagellar pocket. Nucleus central, contractile vacuole just above flagellar pocket. Cells swim rapidly either along substrate or in water phase; during movement cells rotate along their longitudinal axis, from left to right as viewed from dorsal side. (ref. ID; 4907)

Comments

All named species of Cryptaulax and the characters used to distinguish them are listed in Table 2. The species observed here seems to fit Skuja's description of C. vulgaris although it is slightly smaller. It is distinguishable from C. longiciliatus and C. formica which are much larger; from C. conoidea by shape; from C. akopos by the prominence of the groove; from C. thiophila by the compression, groove and slightly larger size; and from C. marina, C. elegans and Rhynchoboda taeniata because of their different rostral morphologies. We are unable to distinguish the organism observed in this study from Cryptaulax marina sensu Vors (1992), which we regard as having been misidentified with the organism named by Throndsen (1969) because of differences in rostral characters. Flagellates referred to as Cryptaulax vulgaris have been report from groundwater by Novarino et al. (1994). (ref. ID; 4907)

Measurements

Length 10-13 um, breadth 3-4 um. (ref. ID; 4907)