Xenophyophores

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Xenophyophores
Xenophyophores in the Atlantic

Xenophyophores in the Atlantic

Systematics
without rank: Diaphoreticks
without rank: Sar
without rank: Rhizaria
without rank: Retaria
without rank: Foraminifera (Foraminifera)
Xenophyophores
Scientific name
Xenophyophorea
Schulze , 1904

The xenophyophore are likely to foraminifera belonging taxon mostly housing-bearing protists from the group of rhizaria . Their enormous size of up to 25 centimeters for single-celled creatures is extraordinary. Xenophyophores live in the deep sea.

features

Xenophyophores reach sizes from a few millimeters up to 25 centimeters and have pseudopods . All species form agglutinated housings, i.e. housings made from collected particles (Xenophyae). The cell itself is organized as a syncytium , i.e. it has several cell nuclei, in addition to which there are granellae, characteristic collections of barium sulfate crystals. The cell is surrounded by a branched system of tubes, the so-called granellar, from which ligaments of feces, the stercomars, emerge.

Granuloreticulopodia, gametes with two flagella, and heterocaries are known of some xenophyophores .

Distribution and ecology

Little is known about the way of life of the xenophyophores. They are widespread in the abyssal and bathyal of the deep sea, where they mainly colonize particularly nutrient-rich regions such as the peaks or slopes of mountains or sea floors below particularly productive surfaces.

In particular, the regions around New Zealand and the equatorial zones of the Eastern Pacific are hotspots in which xenophyophores often make up the main part of the biomass at their locations.

Xenophyophores presumably feed on small foraminifera.

Due to their complex shape, the shells of larger xenophyophores are a habitat, a retreat and a source of food for numerous small organisms. Larger gatherings of animals can thus represent a place of local biodiversity.

Xenophyophores the size of a golf ball

Systematics

The exact systematic position of 1904 by Franz Eilhard Schulze first described xenophyophore using conserved copies of the Siboga Expedition has long been controversial until recent molecular studies suggested that up to now as a separate class of uncertain position understood group on foraminifera is counting , their closest known relatives are species of the genus Rhizammina ( Astrorhizida ). Since only one type of group could be examined so far, the results are still preliminary and require confirmation.

The total number of species is assumed to be around 100, and there are currently almost 60 species in 14 genera known. These are classically divided into 2 orders:

Individual evidence

  1. ↑ a b c d e Jan Pawlowski, Maria Holzmann, Jose Fahrni, Susan L. Richardson: Small Subunit Ribosomal DNA Suggests that the Xenophyophorean Syringammina corbicula is a Foraminiferan In: Journal of Eukaryotic Microbiology, 50: 6, 2003, p. 483– 487
  2. ^ OS Tendal: Synoptic checklist and bibliography of the Xenophyophorea (Protista), with a zoogeographical survey of the group In: Galathea Report 17, 1996
  3. ↑ Christie A. Robinson, Joan M. Bernhard, Lisa A. Levin, Guillermo F. ​​Mendoza, Jessica K. Blanks: Surficial Hydrocarbon Seep Infauna from the Blake Ridge (Atlantic Ocean, 2150 m) and the Gulf of Mexico (690-2240 m) In: Marine Ecology, 25: 4, p. 332, 2004
  4. ^ OS Tendal: Synoptic checklist and bibliography of the Xenophyophorea (Protista), with a zoogeographical survey of the group In: Galathea Report 17, 1996

Web links

Commons : Xenophyophores ( Xenophyophorea )  - Collection of images, videos and audio files