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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Poroecus

Poroecus Cleve, 1902

[ref. ID; 3597]
Lorica capsular; oral margin entire or roughened; bowl usually cylindrical; aboral region rounded or convex conical, with or without an aboral horn; wall composed of two lamellae which are often almost fused, secondary reticulated structure sometimes visible, coccoliths generally attached to the surface. (ref. ID; 3597)
  1. Poroecus apicatus Kofoid & Campbell (ref. ID; 4046)
  2. Poroecus apiculatus (Cleve) Cleve (ref. ID; 3597, 4046)
  3. Poroecus curtus Kofoid & Campbell (ref. ID; 4046)
  4. Poroecus rotundatus Hada, 1935 (ref. ID; 3597, 4600 original paper)

Poroecus apicatus Kofoid & Campbell (ref. ID; 4046)

Descriptions

The tubular lorica is bluntly pointed posteriorly. Coccoliths cover the entire lorica evenly in rows. (ref. ID; 4046)

Measurements

The dimensions of this species are: length 50-72, width 27 um (n=2). (ref. ID; 4046)

Poroecus apiculatus (Cleve) Cleve (ref. ID; 3597, 4046)

Descriptions

Lorica tall goblet-shaped, 3.2 oral diameters in length; oral margin almost entire; bowl subcylindrical, slightly tapering (5 degrees); aboral region abruptly narrowing (68 degrees) with a tubular horn, of which the length is 0.42 of the total length; wall bearing coccoliths fixed thicker on the posterior part than on that of the anterior. (ref. ID; 3597)
The tubular lorica, with coccoliths irregularly arranged on it, has an aboral region ending in a horn of variable length. (ref. ID; 4046)

Comments

The species differs from the other species of Poroecus in having an elongate aboral horn. This species is variable in the structure of the lorica: the specimens reported by Brandt (1906-7) as this species from the Sargasso Sea did not bear coccoliths on the surface and secondary reticulated structure was apparently seen, and ones of the South Equatorial Stream of the Pacific examined by Kofoid & Campbell (1929) exhibited an irregular oral margin. (ref. ID; 3597)

Measurements

Length 95; oral diameter 30; aboral horn 40 um. (ref. ID; 3597)
The dimensions of the lorica are: length 96-102, width 31 um (n=2). (ref. ID; 4046)

Poroecus curtus Kofoid & Campbell (ref. ID; 4046)

Descriptions

the lorica is characterized by having a short posterior knob on the aboral end of the tubular structure. The arrangement and number of coccoliths on the lorica varies from very patchy to evenly spaced. (ref. ID; 4046)

Measurements

The dimensions of the lorica are: length 60-67, width 28+/-0.9 um (n=8). (ref. ID; 4046)

Poroecus rotundatus Hada, 1935 (ref. ID; 3597, 4600 original paper)

Descriptions

Lorica stout capsular, 1.1 oral diameters in length, more or less cylindrical in the upper half, rounded in the lower; wall with variously size coccoliths on the surface. (ref. ID; 3597)

Comments

The species differs from the other published species of Poroecus in rotund outline. (ref. ID; 3597)

Measurements

Length 40; oral diameter 36 um. (ref. ID; 3597)