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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Undella

Undella Daday, 1887

[ref. ID; 3597]
Lorica capusular or pot-shaped without a suboral ledge or a definite inner collar; bowl cylindrical or globose; aboral end rounded, conical, or flattened; wall entirely separated, hyaline, usually thinning towards the aboral end. (ref. ID; 3597)
Type species; Undella hyalina Daday (ref. ID; 3597)
  1. Undella aculeata (ref. ID; 3319)
  2. Undella antarctica Hada, 1970 (ref. ID; 3544 original paper)
  3. Undella caudata (ref. ID; 3319)
  4. Undella claparedei (ref. ID; 3319)
  5. Undella clevei (ref. ID; 4464)
  6. Undella declivis (ref. ID; 4464)
  7. Undella hemispherica Laachmann (ref. ID; 4046) or Laackmann (ref. ID; 3597)
  8. Undella hyalina (ref. ID; 3319)
  9. Undella pellucida Jorgensen, 1899 in part
    See; Parundella pellucida (ref. ID; 3606)
  10. Undella subacuta (ref. ID; 3319)
  11. Undella turgida Kofoid & Campbell (ref. ID; 3597)

Undella antarctica Hada, 1970 (ref. ID; 3544 original paper)

Descriptions

The hyaline lorica is sac-shaped with a broadly rounded aboral end. The anterior part composed of a thickened wall has a suboral inflated band and an inner funnel-shaped collar, which is a characteristic of the forms of the Subgenus Proplectella Kofoid & Campbell (1929). Therefore, the precise name of the new species should be Undella (Proplectella) antarctica Hada. (ref. ID; 3544)

Comments

The new species differs from the typical forms of genus Undella Daday (1887) in having an inner collar, and from those of the Subgenus Proplectella in having a suboral expantion. (ref. ID; 3544)

Type locality

This species collected from the antarctic sea of the region of Syowa Station. (ref. ID; 3544)

Measurements

Length 53; breadth 38; oral diameter 28 um. (ref. ID; 3544)

Undella hemispherica Laachmann (ref. ID; 4046) or Laackmann (ref. ID; 3597)

Descriptions

Lorica rotund, cup-shaped, 1.26-1.41 oral diameters in length; oral rim with a slight brim, not acute; bowl more or less dilated in the suboral 0.22-0.25 of the lorica, weakly constricted below its expansion, broadest at the point of the anterior 0.4 of the lorica, its greatest diameter 1.24-1.34 oral diameters and a little larger than or nearly equal to that of the suboral dilated part; aboral region hemispherical or broadly convex conical with a round aboral end; wall thickened in the suboral inflated region, gradually thinning towards the thinnest aboral end. (ref. ID; 3597)
The lorica of this species is hyaline, short, rounded, and bluntly pointed aborally, with the greatest width at the middle. The wall appears thickened throughout when examined by light microscopy. (ref. ID; 4046)

Comments

The species differs from U. turgida Kofoid & Campbell in showing greater dimensions and having no marked aboral inflation. (ref. ID; 3597)

Measurements

Length 60-65; oral diameter 46-50; greatest transdiameter 57-64 um. (ref. ID; 3597)
The dimensions of the lorica are: length 63-65, maximum width 58-61, oral width 46 um (n=2). (ref. ID; 4046)

Undella turgida Kofoid & Campbell (ref. ID; 3597)

Descriptions

Lorica stout, pot-shaped, 1.46 oral diameters in length; bowl ovate, sloping outwardly (80 degrees) almost from the oral margin by an inflated suboral part in the anterior 0.45 of the lorica, broadest at the position of the suboral 0.36 of the total length, its greatest transdiameter 1.50 oral diameters; aboral region widely convex conical (110 degrees); aboral end bluntly pointed; wall thicker in the suboral dilated part, thinnest in the aboral end. (ref. ID; 3597)

Comments

The species differs from U. hemispherica Kofoid & Campbell in being smaller in size and having a great suboral dilated part. (ref. ID; 3597)

Measurements

Length 38; oral diameter 26; greatest transdiameter 40 um. (ref. ID; 3597)