Acantharea

Live specimen, from the Bay of Villefranche, September 19 2012. Composite image of two focal planes showing the frame and one set of the interior spines of the skeleton. See the video on the Aquaparadox site - video page. or YouTube (search Lithoptera)

Lithoptera fenestrata - focusing through the skeleton to show the complicated 3-D structure

Description: English: Illustration from Report on the Radiolaria collected by H.M.S. Challenger during the years 1873-1876. Part III. Original description follows: Plate 130. Astrolonchida. Diam. Fig. 1. Acanthometron bulbiferum, n. sp.,: ×: 300. Fig. 2. Acanthometron cylindricum, n. sp.,: ×: 200. Fig. 3. Lithophyllium gladiatum, n. sp.,: ×: 200. Fig. 4. Stauracantha quadrifurca, n. sp.,: ×: 300. Fig. 5. Stauracantha orthostaura, n. sp.,: ×: 200. Fig. 6. Phatnacantha icosaspis, n. sp.,: ×: 400. Fig. 7. Pristacantha polyodon, n. sp.,: ×: 300. Fig. 8. Pristacantha dodecodon, n. sp.,: ×: 300. Only the central parts and the leaf-cross. Fig. 9. Pristacantha octodon, n. sp.,: ×: 200. Date: 1887. Source: https://archive.org/details/reportonradiolar00haecrich. Author: Ernst Haeckel (1834-1919); engravings by Adolf Giltsch (1852-1911).

Njar, Andalusia, Spain

Njar, Andalusia, Spain

Njar, Andalusia, Spain

Njar, Andalusia, Spain

Njar, Andalusia, Spain

Diploconus hexaphyllus.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. The outermost region of cytoplasm attaches to the arms with contractile ligaments or myonemes about halfway along their length. The cells often have an orange or brown colour because of the presence of symbiotic dinoflagellates. Phase contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. This image has been taken with polarised light so the the crystalline appearance of the arms is more evident. Phase contrast with polarised light.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. As can be seen in this micrograph, the outermost region of cytoplasm attaches to the arms with contractile ligaments or myonemes about halfway along their length. Phase contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. The outermost region of cytoplasm attaches to the arms with contractile ligaments or myonemes about halfway along their length. Phase contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. The symbiotic dinoflagellates which give the acantharea an orange or brown colour can be seen here. Differential interference contrast.

Astrolithium (astro-lith-ee-um) is one of the more commonly encountered acantharea. These star-shaped organisms used to be grouped with polycystines and phaeodarea as radiolaria. These three groups all have inorganic skeletons to which the cytoplasm attaches, usually have an inner condensed area of cytoplasm and an outer more open region, and have a star-like morphology. Like other acantharea, the spines of Astrolithium are made of strontium salts which readily dissolve when the cells die. There are 20 radiating spines which are linked together at the centre of the cell. This image shows a young cell attached to a larger cell. Phase contrast.

Acanthochiasma fusiforme. To obtain the best quality downloads, please visit the virtual library of Kurt Stueber.

Acanthometra bulbosa. To obtain the best quality downloads, please visit the virtual library of Kurt Stueber.

Acanthostaurus purpurescens. To obtain the best quality downloads, please visit the virtual library of Kurt Stueber.

Acanthostaurus purpurescens. To obtain the best quality downloads, please visit the virtual library of Kurt Stueber.

Icosaspis elegans.

Haeckel says: An isolated polar plate.