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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Corallomyxa

Corallomyxa Grell, 1966 (ref. ID; 4753)

Class Amoebea: Subclass Gymnamoebia: Uberordnung Mycetozoidea: Order Promycetozoida (ref. ID; 4753)
  1. Corallomyxa chattoni Grell & Benwitz, 1978 (ref. ID; 4753)
  2. Corallomyxa multipara Grell, 1988 (ref. ID; 4753 original paper)
  3. Corallomyxa mutabilis Grell, 1966 (ref. ID; 4753)
  4. Corallomyxa nipponica Grell, 1991 (ref. ID; 4803 original paper)

Corallomyxa nipponica Grell, 1991 (ref. ID; 4803 original paper)

Descriptions

Corallomyxa nipponica has a holoplasmodial organization. Cell bodies and reticulopodia cannot be distinguished. Grown on a lawn of diatoms, the holoplasmodium forms a regular network which may cover a whole slide or the bottom of a Petri dish completely. The appearance of the network depends on its age: Young network have thin strands forming large meshes, old networks have thick strands around small meshes. There are of course all transitions between both extremes, but rarely differences within the same network. Masses of diatoms can quickly be engulfed. The majority is enclosed in single vacuoles, but these may later fuse to form larger ones. Occasionally, large vacuoles containing empty diatom shells adhere to the network like globular bags. They may detach from the plasmodium and sink to the bottom, still surrounded by a membrane. Older plasmodia show areas of condensation where the meshes become smaller and smaller and the strands fuse to form a condensed area. In Corallomyxa multipara (Grell, 1988) such area are the starting points of multiple budding, leading to the so-called floating buds which serve for the dissemination of the species. Corallomyxa nipponica produces floating buds in an unusual way. When the diatoms become sparse, the plasmodial network undergoes a striking alteration. Some of its meshes, often in close proximity, contain a small, amoeba-like portion in the center which is connected with the surrounding meshwork by thin treads. Squeezed preparations indicate that such central portions become separated from the remaining network and contain one nucleus only. After the formation of pseudopodia-like extensions, the uninucleate bud is set free and floats in the seawater. Sooner or later it sinks to the bottom and creeps about. Occasionally, binucleate buds were observed. They contain no food vacuoles and do not seem to be the result of growth and nuclear division, but a product of fusion, as described for Corallomyxa multipara (Grell, 1988). The development of the buds into plasmodial networks is not principally different from the process in Corallomyxa multipara. (ref. ID; 4803)

Type locality

From tide pools near the Shimoda Marine Research Center (Japan). (ref. ID; 4803)