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Bicosoeca James-Clark, 1867 (ref. ID; 4907, 4921, 5772) reported year? (ref. ID; 1618)

Order Stramenopiles Patterson, 1989 (ref. ID; 4907)

[ref. ID; 1618]
With vase-like lorica; body small, ovoid with rudimentary collar, a flagellum extending through it; protoplasmic body anchored to base by a contractile filament (flagellum?); a nucleus and a contractile vacuole; attached or free-swimming. (ref. ID; 1618)

[ref. ID; 4907]
Stramenopile flagellates surrounded by an organic lorica, to which the smooth flagellum is attached by its tip (Preisig et al. 1991). No chloroplast (Moestrup & Andersen 1991). When cells are disturbed, the recurrent flagellum contracts and the anterior flagellum is rolled up in a tight coil; this behaviour is diagnostic (Preisig et al. 1990). Lorica morphology is used to distinguish between species, and several different species of Bicosoeca were observed in this study. In most cases ultrastructual examination is necessary for a proper identification. (ref. ID; 4907)
See Poteriodendron.
  1. Bicosoeca conica (ref. ID; 2659)
  2. Bicosoeca crystallina (Lackey) Skuja, 1956 (ref. ID; 4921)
  3. Bicosoeca cylindrica (Lackey) Bourrelly, 1951 (ref. ID; 4921)
  4. Bicosoeca epiphytica Hilliard (ref. ID; 4907)
  5. Bicosoeca kepneri Reynolds, 1926 (ref. ID; 5772) reported year? (ref. ID; 1618)
  6. Bicosoeca lacustris James-Clark, 1867 (ref. ID; 4921, 5772)
  7. Bicosoeca mignotii Moestrup, Thomsen & Hibberd in Vors, 1992 (ref. ID; 4907)
  8. Bicosoeca mitra (ref. ID; 2659)
  9. Bicosoeca parva Hilliard, 1971 (ref. ID; 4907)
  10. Bicosoeca petiolatum (Stein) Bourrelly, 1951 (ref. ID; 4921)
  11. Bicosoeca planktonica Kisselew, 1931 (ref. ID; 4921) reported author and year? (ref. ID; 2659)
  12. Bicosoeca pulchra Hilliard, 1971 (ref. ID; 4907)
  13. Bicosoeca socialis Lauterborn (ref. ID; 1618) or (Lauterborn) Skuja, 1956 (ref. ID; 4921)

Bicosoeca epiphytica Hilliard (ref. ID; 4907)


Protoplast rounded to oval, 6-9 um long; lorica chamber about 20 um, conical to bell-shaped, tapering gradually towards bottom. The wide opening with incurved margin. Lorica stalk thin, one to two times as long as lorica chamber. (ref. ID; 4907)


This species can be distinguished from similar species such as Bicosoeca pulchra Hilliard, 1971 and B. parva Hilliard, 1971 by size and relative proportions. It is possible that these differences reflect environmental conditions and not genomic factors (Tong, pers. com.). The species is also reminiscent of some Stokesiella species (Lemmermann 1910). The latter, however, have two emergent flagella, neither of which roll up in a tight coil when the cell is disturbed. (ref. ID; 4907)

Bicosoeca kepneri Reynolds, 1926 (ref. ID; 5772) reported year? (ref. ID; 1618)


Body pyriform. (ref. ID; 1618)
Lorica ovoid or ellipsoidal and stalked. The anterior end of the lorica is closed when the protoplast is retracted to the bottom of the lorica. It is forced open by the protoplast as it protrudes for feeding. The protoplast is globular-ovoid, and has a conspicucus peristomal lip. (ref. ID; 5772)


This species closely resembles the fresh water species Bicosoeca kepneri and Bicosoeca lacustris in overall morphology and elasticity of the lorica (Bachmann 1911; James-Clark 1867; Klug 1936; Mignot 1974; Stein 1878). It differs only by being slightly smaller and because it was found in a saline habitat. The size difference is not regarded as significant, and other fresh water species have been recorded in salt waters (e.g. Bicosoeca conica Lemmermann, 1914 (Larsen & Patterson 1990)). Bicosoeca kepneri and B. lacustris differ in the substructure of the lorica as revealed by electron microscopical thin sections (Mignot 1974). The present species was not found in the EM preparations, and thus cannot be identified with certainty. (ref. ID; 5772)

Previous records

Both species are widespread in N. American and European fresh waters (Mignot 1974). (ref. ID; 5772)


Body 10 by 6 um; lorica about 1.5 times the body length; flagellum about 30 um long. (ref. ID; 1618)
Lorica: 5-6x7-9 um (4-10x10-25 um); protoplast: 2-3x3-4 um (length: 6-12 um). (ref. ID; 5772)

Bicosoeca mignotii Moestrup, Thomsen & Hibberd in Vors, 1992 (ref. ID; 4907)


Cell oval, 6-7 um long, lorica chamber 7-9 um, lorica stalk 3-10 um. Lorica chamber ovoid, distal part divided in two beak-like structures. Lorica with stalk attached to substrate by basal disc about 2 um in diameter. (ref. ID; 4907)


The beak-like structures and the well defined basal disc are distinctive features of this species. Common in freshwater, and recorded from brackish water (Vors 1992). (ref. ID; 4907)

Bicosoeca socialis Lauterborn (ref. ID; 1618) or (Lauterborn) Skuja, 1956 (ref. ID; 4921)


Lorica cylindrical; often in groups; free-swimming in fresh water. (ref. ID; 1618)


Lorica 23 by 12 um; body about 10 um long. (ref. ID; 1618)