Chaunacanthida
| Chaunacanthida | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Chaunacanthida | ||||||||||||
| Schewiakoff , 1926 |
The Chaunacanthida are an order of unicellular , marine organisms from the group of Acantharia .
description
The skeletons of the Chaunacanthida have 20 spines. The tips of the spines are elongated round, similar to cones, and stored in a contractile mass. In cross-section, the spines are cross-shaped, two opposite edges are serrated, the other two smooth.
The endoplasm is pigmented black or reddish in the center , it becomes clearer towards the edge. The ectoplasm is transparent. The capsule wall is clearly pronounced in some of the genera. The periplasmic cortex has elastic connections that are arranged in a rectangular pattern. The exceptionally long and flexible muonemes are ribbon-like.
Before gametogenesis , the cell undergoes a morphogenetic transformation that leads to a special stage in the life cycle, the so-called litholophus . The spines lie in one direction, similar to a folded umbrella, the cell becomes smaller and takes on an elongated, round shape, elements such as muonemes, periplasmic cortex and cell nuclei migrate to the back of the cell. The whole cell then slowly and actively moves forward in the water and then begins to encyst .
Systematics
The order was first described by Vladimir Schewiakoff in 1926 , it contains three families:
proof
- ^ A b c d Colette Febvre, Jean Febvre, Anthony Michaels: Acantharia. In: John J. Lee, GF Leedale, P. Bradbury (Eds.): An Illustrated Guide to the Protozoa . tape 2 . Allen, Lawrence 2000, ISBN 1-891276-23-9 , pp. 791 .
- ^ Colette Febvre-Chevalier, Jean Febvre: Buoyancy and swimming in marine planktonic protists. In: J Rayner, Q. Bone (Ed.): Mechanics and physiology of animals swimming. 1994, Plymouth, Polytechnic South West, p. 13.