Watering can sponge
| Watering can sponge | ||||||||||||
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Watering can sponge |
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| Euplectella aspergillum | ||||||||||||
| Owen , 1841 |
The watering can sponge ( Euplectella aspergillum ) is a species from the class of glass sponges . In English , the sponge is also called " Venus' flower basket ", as it serves as a habitat for a couple of some marine shrimp species of the Stenopodidea .
description
Euplectella aspergillum reaches a body length of about 40 to 240 millimeters with a diameter of 14 to 50 millimeters. The body forms a hollow, tube-like structure with thin, but very stable walls due to the internal skeleton of fused skeletal needles . The large upper opening of the atrium is through a porous, screen or by sudden closed plate. The sponge body sits directly on the substrate, without a stem section, it is slightly narrowed towards the basal end. It is anchored by a clump of protruding, basalia called skeletal needles (so-called "lophophytic" anchoring type), this is, typical for the genus, simple and undivided. The individual needles are 5 to 15 centimeters long with a diameter of only 40 to 70 micrometers. The anchoring enables the species to colonize soft substrates on the sea floor. The side wall of the sponge body has numerous pore-like openings, these are the outflow openings or oscula , through which the water flowing into the central, chimney-like cavity (called atrium) flows out again after it has been filtered in the numerous small filter chambers located within the wall. The Oscula are each 1 to 2 millimeters wide, they sit on two imaginary, counter-rotating spirals that intersect at an angle of 45 degrees. In older individuals, these spirals are partially traced by rib-like reinforcements that sit on the outside, but these can be interrupted or missing.
As is typical for glass sponges, the skeletal needles of the body consist of two size classes, the larger macrosclerae and the individually seated, star-shaped microsclerae that are only fractions of a millimeter long. The so-called choanosomal macrosclerae of the inside of the body are fused into a filigree, lattice-like or cage-like skeleton in the species by sinter-like deposits on the outside, which are called synapticulae. Most of the macrosclerae in the species are four-pointed (because of the cross shape from Greek stauros , called "stauractines"), but there are also five- and, actually typical for the lower class, six-pointed needles.
Properties of the skeleton
As with all glass sponges, the skeletal needles or spicules are made of biogenic opal ( amorphous silicon dioxide ). The skeleton of needles fused together reveals a lattice structure of struts crossing at right angles, which consist of individual needles that are arranged in parallel and fused together. Every second grid cell formed in this way is stiffened by diagonal struts. The individual needles are made of glass-like, amorphous opal, which surrounds a central axis thread made of protein in lamellar layers; protein layers are also inserted between the lamellae, so that a composite material results that is tougher and more flexible than pure glass fiber. This construction results in a remarkably high mechanical stability.
In addition to the mechanical properties, the skeleton needles of the watering can sponge have optical properties that are similar to those of fiberglass cables. As in these, incident light is guided through different refractive indices in the central cylinder and thus carried on along the fiber. The efficiency is further increased by the lens-like widenings at the end of the fibers. The biological function of this property is unclear for the species. In other types of sponges, a function for the transmission of light into the interior of the sponge body could be demonstrated in order to supply symbiotic algae with light; this does not matter with the watering can sponge. In another species, Suberites domuncula , the presence of a luciferase , and thus luminosity ( bioluminescence ), as well as the presence of photosensitive proteins were detected, which make a nerve-like transmission of information through the needles appear possible within the organism. Corresponding evidence, even for bioluminescence itself, also for the watering can sponge is still pending.
Researchers suspect that the fibers of the sponge can be used as models for new optical conductors, as their light conductivity is superior to that of ordinary glass fibers. The stable lattice structure, which makes the sponge almost unbreakable, could also serve as a model for human architecture.
Coexistence with shrimp
The species is known for the fact that in its interior there is very often a pair of males and females of shrimp of the family Spongicolidae ( Stenopodidea ), in particular of the species Spongicola venustus . The shrimp are so large that they cannot fit through the existing openings so that they cannot leave the sponge. The shrimp have a smooth, non-calcified carapace and partially reduced sensory organs and cleaning facilities; they cannot survive long outside the sponges. The relatively large larvae are released into the open water (they can still easily fit through the mesh). Young shrimp colonize sponge organisms as long as the skeletal elements have not yet fused with one another and are therefore still soft. They feed on food particles washed into the sponge by the flow of water, so they live as its commensals .
This relationship, in which a couple comes together in a permanent house and never leaves it voluntarily, is said to have encouraged the use of the species as a symbolic wedding gift in Japan.
habitat
The watering can sponge is found in the western Pacific and eastern Indian Ocean , the nominate form around the Philippines . It is found in stony regions on the sea floor at depths between 100 m and 1000 m, often deeper than 500 m.
Systematics
Euplectella aspergillum is the type species of the genus Euplectella Owen, 1841. This comprises 17 species that are very similar and difficult to identify. In addition to the nominate form , three subspecies are distinguished within the species .
- Euplectella aspergillum aspergillum Owen, 1841. Philippines
- Euplectella aspergillum australicum Tabachnick, Janussen & Menschenina, 2008. found off Port Hedland , Australia
- Euplectella aspergillum indonesicum Tabachnick, Janussen & Menschenina, 2008. Indonesia ( Sunda Strait ), Malaysia,
- Euplectella aspergillum regalis Schulze, 1900 ( Syn .: Euplectella regalis ). Indian Ocean
Individual evidence
- ↑ a b Joanna Aizenberg, Vikram Sundar C., Andrew D. Yablon, James C. Weaver, Gang Chen (2004): Biological glass fibers: Correlation between optical and structural properties. PNAS Proceedings of the National Academy of Sciences USA 101 (10): 3358-3363. doi: 10.1073 / pnas.0307843101
- ↑ a b Konstantin R. Tabachnick: Family Euplectellidae. in: John Hooper, Rob WM van Soest (editors): Systema Porifera: A Guide to the Classification of Sponges. Kluwer Academic / Plenum Publishers, New York, 2002. ISBN 978-1-4615-0747-5 . Euplectella aspergillum on page 1391.
- ↑ Joanna Aizenberg, James C. Weaver, Monica S. Thanawala, Vikram C. Sundar, Daniel E. Morse, Peter Fratzl (2005): Skeleton of Euplectella sp .: Structural Hierarchy from the Nanoscale to the Macroscale. Science 309 (5732): 275-278. download
- ^ Franz Brümmer, Martin Pfannkuchen, Alexander Baltz, Thomas Hauser, Vera Thiel (2008): Light inside sponges. Journal of Experimental Marine Biology and Ecology 367: 61-64. doi: 10.1016 / j.jembe.2008.06.036
- ↑ XiaoHong Wang, XingTao Fan, Heinz C. Schröder, Werner EG Müller (2012): Flashing light in sponges through their siliceous fiber network: A new strategy of “neuronal transmission” in animals. Chinese Science Bulletin 57 (25): 3300-3311. doi: 10.1007 / s11434-012-5241-9 (open access)
- ↑ which also occurs in related sponge species. Tonomi Saito & Tomoyuki Komai (2008): A review of species of the genera Spongicola de Haan, 1844 and Paraspongicola de Saint Laurent & Cleva, 1981 (Crustacea, Decapoda, Stenopodidea, Spongicolidae). Zoosystema 30 (1): 87-147.
- ^ Joseph W. Goy (2010): Infraorder Stenopodidea Claus, 1872. Treatise on Zoology - Anatomy, Taxonomy, Biology. The Crustacea, Volume 9 Part A, 215-265. doi : 10.1163 / 9789004187801_009
- ^ Beau McKenzie Soares (2001): Euplectella aspergillum ADW Animal Diversity Web, University of Michigan Museum of Zoology. Retrieved May 3, 2017.
- ^ Van Soest, R. (2008). Euplectella Owen, 1841 In: van Soest, RWM; Boury-Esnault, N .; Hooper, JNA; Rützler, K .; de Voogd, NJ; Alvarez de Glasby, B .; Hajdu, E .; Pisera, AB; Manconi, R .; Schoenberg, C .; Klautau, M .; Picton, B .; Kelly, M .; Vacelet, J .; Dohrmann, M .; Díaz, M.-C .; Cárdenas, P .; Carballo, JL (2017). World Porifera database. Accessed through WoRMS World Register of Marine Species, accessed May 2, 2017.
- ↑ Konstantin R. Tabachnick, Dorte Janussen, Larisa L. Menschenina (2008): New Australian Hexactinellida (Porifera) with a revision of Euplectella aspergillum. Zootaxa 1866: 7-68.
Web links
- Peter Fratzl, Katja Schulze: Biological glass cage from the deep sea. German-American research team deciphered the construction principles according to which the glass skeleton of glass sponges is constructed. Max Planck Society, July 7, 2005, accessed on September 16, 2011 .
- Critter of the Week: the venus flower baskets Euplectellidae NIWA National Institute of Water and Atmospheric Research, New Zealand. Retrieved May 3, 2017.
