Monorhaphis chuni
| Monorhaphis chuni | ||||||||||||
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Monorhaphis chuni , upper part, laterally opened (right picture) |
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| Systematics | ||||||||||||
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| Scientific name of the family | ||||||||||||
| Monorhaphididae | ||||||||||||
| Iijima , 1927 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Monorhaphis | ||||||||||||
| Schulze , 1904 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Monorhaphis chuni | ||||||||||||
| Schulze , 1904 |
Monorhaphis chuni is a type of glass sponge thatliveson soft substrates in the deep sea. The species is remarkable for its gigantic skeletal needles (spicula), which can reach a length of three meters.
features
The body of the sponge is elongated and cylindrical with a round to oval cross-section, it reaches about 10 to 15 centimeters in diameter. The body surface is divided on one side by a sunk atrium into which numerous outflow openings ( oscula ) of the sponge body with a diameter of a good 1 centimeter open. The body is traversed lengthways by a gigantic basal needle, which is about eight millimeters thick and can reach a length of three meters. This needle protrudes below the sponge body; this lower end is in the substrate of the sea floor and anchors the organism in it. While this is the only form of the large spicula (megasclera), there are also 14 different forms of small needles (microsclera), the length of which ranges from a few micrometers to around 50 millimeters: The choanosomal skeleton (which supports the body and the canal system) consists mainly made of three-pronged (triactine) needles. The needles (dermalia) located below the surface are predominantly five-pointed, sometimes also six-pointed, as is actually typical for the glass sponges. In addition, there are three types of so-called amphidiscs (typical spicula shape of the amphidiscophora ). As is typical for all Amphidiscophora, the needles are single and not fused.
Structure of the basal needle
The huge basal needle of the species has received special scientific attention. It is the largest biogenic silicate structure in the entire animal kingdom. Three zones can be distinguished in the cross-section in Feinbau: A thin, central axis thread, which is surrounded by an axis cylinder made of amorphous silicate of around 100 to 150 micrometers. The main part of the needle consists of 300 to 800 thin, concentric lamellae. These are separated by thin, slit-shaped strips that are not continuous all round, so that neighboring lamellas appear partially fused with one another. As is typical for glass sponges, the needles consist of water-based, non-crystalline silicon dioxide (biogenic opal ). The slits between the lamellae are filled with a matrix of proteins . The result is a composite material of unusual strength, in particular its flexural strength is much higher than that of pure glass needles. The essential protein of the needles, silicatein , belongs to the cathepsin family of proteins . It serves both as a structural protein and for the enzymatic separation of silicon dioxide from the surrounding solution, where it is kept in solution by another enzyme, silicase. As another structural protein, collagen is involved in the structure.
A skeletal needle of an animal that was found off the south Chinese coast at a depth of 1110 meters was examined in layers for the ratio of the oxygen isotopes 18 O to 16 O and the calcium / magnesium ratio, both indicators for the temperature of the sea water (cf. δ18O ). If the determined curve is projected onto the temperature profile in this marine region estimated from other sources, this results in an estimated age of 11,000 years (plus / minus 3,000). As with many deep-sea dwellers, this results in an unusual age for the sponge individual, which could have been one of the oldest living organisms, the age of which could previously be dated.
distribution
Monorhaphis chuni is found in the Indian Ocean and the adjacent western Pacific , for example off the coast of Somalia, the island of Zanzibar , China, Indonesia, the Andaman Islands and the Philippines. Evidence is available from sea depths of 516 to 1920 meters. The species colonizes soft substrates.
Taxonomy, phylogeny, history of research
The species was first found on the Valdivia expedition to explore the deep sea 1898–1899 and named after the expedition leader Carl Chun by its first describer, Franz Eilhard Schulze .
The species is now considered the only representative of the genus Monorhaphis , which is thus monotypical . Two other species were described in the genus (one of them by Schulze in the same publication as Monorhaphis chuni ), but these were later synonymous with Monorhaphis chuni . The genus is again the only member of the Monorhaphididae family. The position of the family within the Amphidiscophora is considered to be certain, although it has not yet been substantiated by molecular studies.
swell
- Konstantin R. Tabachnick: Family Monorhaphididae Ijima, 1927. In: John NA Hooper, Rob WM Van Soest, Philippe Willenz (editors): Systema Porifera. A Guide to the Classification of Sponges. Springer, 2002. ISBN 978-0-306-47260-2 , pp. 1264-1266.
- Xiaohong Wang, Lu Gan, Klaus P. Jochum, Heinz C. Schröder, Werner EG Müller : The Largest Bio-Silica Structure on Earth: The Giant Basal Spicule from the Deep-Sea Glass Sponge . In: Evidence-Based Complementary and Alternative Medicine . No. 540987 , 2011, pp. 1–14 , doi : 10.1155 / 2011/540987 ( PDF ).
- Klaus Peter Jochum, Xiaohong Wang, Torsten W. Vennemann, Bärbel Sinha, Werner EG Müller: Siliceous deep-sea sponge Monorhaphis chuni: A potential paleoclimate archive in ancient animals . In: Chemical Geology . tape 300-301 , 2012, pp. 143–151 , doi : 10.1016 / j.chemgeo.2012.01.009 .
- G. Wörheide, M. Dohrmann, D. Erpenbeck, C. Larroux, M. Maldonado: Deep Phylogeny and Evolution of Sponges (Phylum Porifera) . In: Advances in Marine Biology (= Advances in Sponge Science: Phylogeny, Systematics, Ecology ). tape 61 . Academic Press, 2012, chap. 1 , p. 1-78 , doi : 10.1016 / B978-0-12-387787-1.00007-6 .
- Karl Eilhard Schulze (1902): Hexactinellida. In: Carl Chun (editor): Scientific results of the German deep-sea expedition on the steamer "Valdivia" 1898-1899. Full text at archive.org
- Monorhaphis chuni at WoRMS World Register of marine Species
