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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Paralembus

  1. Paralembus asturianus Fernandez-Leborans & Zaldumbide, 1984 (ref. ID; 4679 original paper)
  2. Paralembus hargisi (Evens & Thompson, 1964) Borror, 1972
    See; Pseudocohnilembus hargisi (ref. ID; 4520)
  3. Paralembus rostrata Kahl 1933 (ref. ID; 4679) reported author and year? (ref. ID; 191, 4006, 7536)

Paralembus asturianus Fernandez-Leborans & Zaldumbide, 1984 (ref. ID; 4679 original paper)

Diagnosis

Marine ciliata. From 15.6-16.8x10.2-13.2 um. Body slightly oval-shaped. 8 somatic kineties whose kinetosomes show kinetodesmal fibers clearly. Macronucleus composed of 2 nodes more or less the same, disc-shaped, 4.5 um in diameter. 1 micronucleus. Oral area, with a size of 11x4 um, composed of: paroral formation (PF) with 2 parallel rows of kinetosomes, 3 membranelles of which M1 is much longer that the other 2 (M2 and M3). M1 is made up of 8 rows of kinetosomes. M2 and M3 have 2 rows of kinetosomes each. (ref. ID; 4679)

Descriptions

Specimens of this species are relatively small in size. The organism is from 15.6 to 16.8 um in length and from 10.2-13.2 um in width. The body is slightly oval-shaped with round anterior and posterior ends. There are 8 somatic kineties, of which four are located in the ventral side and four in the dorsal side of the organism. These kineties are made up of a small number of kinetosomes (12 in the second kinety at the right of the paroral formation) each of which shows a kinetodesmal fiber clearly, which measures from 1.2-1.32 um; this kinetodesmal fiber is arranged according to the law of desmodexy. The macronucleus of these ciliata is composed of two nodes joined by a not very thin narrowing. The macronuclear group is from 6.6-7.2 um in length and is located in the front half of the ciliate and on the right side. The nodes are located one behind the other, front to back and each node, more or less disc-shaped, has a diameter of 4.5-4.8 um. The narrowing between nodes has a width of 3.24 um on the average. The micronucleus is located beside the posterior end of the macronucleus, at a distance of about 0.48 um; this spherical micronucleus has an approximate diameter of 1.5 um. The oral area is located at the right side of the ventral surface of the ciliate; it is from 10.8-11.4 um in length and from 3.6-4.2 um in width. The anterior end of the oral area is located very near the front pole of the ciliate, at a distance of 1.2 um on average. The oral area exceeds the equator of the ciliate and its rear end is 13.2 um on the average from the front pole of the ciliate. (ref. ID; 4679)
  • Oral ciliature: There are two principal structures: the paroral formation (PF) and the adoral zone of the membranelles (AZM). The paroral formation (PF) is located on the right side and to the rear of the oral area and has a straight part that is located on the right side and a curved part that surrounds the rear zone of the oral area. This structure is made up of two parallel rows of kinetosomes of 13.2-13.8 um in length (stichodyad). Both rows of kinetosomes are located on a thick fibril structure that we call subparoral fiber (SPF). The adoral zone of membranelles (AZM) is located at the left side of the oral area and is made up of three structures of membranelles, from the foremost to the rearmost: M1, M2 and M3. Membranelle M1 is located beside the PF, in front of this PF at its front end, for about 2/3 of the length of the straight part of the PF. M1 is made up of eight rows of kinetosomes that form, towards the apical zone of the ciliate, an angle of approximate 45 degrees with the PF. Each one of these rows is made up of six kinetosomes, except the two front ones, which are longer and curve at the end towards the front pole of the ciliate; these two kineties have 12 kinetosomes each. The group of M1 is from 6.6-7.2 um in length and from 2.1-2.4 um in width. Membranelle M2 is much smaller than the above and is slightly separate from it. Its kinetosomes are much clearly and separate than those of M2. This membranelle is made up of two rows of kinetosomes that are arranged in the same direction as the rows of M1; of these two rows, the foremost is the longest (3.6 um on the average) and has more kinetosomes (8 kinetosomes) than the other, which has four kinetosomes and measures 1.8 um on the average. The membranelle which is furthest to the rear, M3, is located beside the straight PF zone, near the curved PF part which surrounds the rear section of the oral area; it is composed of 2 rows of 2 kinetosomes each and measures 0.6x1.08 um on the average. With this arrangement of oral ciliature, there remains an area at the left of the rearmost zone of the oral area that lacks kinetosomes. In this area there are 2 curved fibers, more or less in parallel: the furthest outward from the oral area (FI) measures from 2.88-3.3 um in length and the furthest inwards toward the oral area (F2) is from 3.54-6.1 um in length. Outside the oral area and beside the rear curved part of the PF, separated from this PF by 0.78 um on the average, is the scutica of the ciliate composed of two kinetosomes. (ref. ID; 4679)

    Comments

    P. asturianus is similar to Paralembus rostrata Kahl, 1933 (Groliere, 1974) although our species is somewhat smaller in size (from 25-45x16-30 um in P. rostrata, from 15.6-16.8x10.2-13.2 um in P. asturianus). Both species are similar with respect to the general arrangement of the oral membranelles; but in our species the longest membranelle is M1 while in P. rostrata the longest membranelle is M2. P. rostrata has a macronucleus more or less spherical-shaped while P. asturianus has 2 spherical-shaped macronuclei of more or less the same size. (ref. ID; 4679)