Porpostoma notatum
| Porpostoma notatum | ||||||||||||
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Porpostoma notatum , illustration from 1888 |
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| Scientific name | ||||||||||||
| Porpostoma notatum | ||||||||||||
| Möbius , 1888 |
Porpostoma notatum is aspecies of ciliate species thatinhabitthe oceans . The unicellular organism is known under the synonym Helicostoma notata in aquaristics because it causes a disease in corals.
features
The cell is - presumably dependent on its diet - extremely variable in terms of its size and body shape. Living individuals are between 60 and 180 micrometers long and 20 to 60 micrometers wide. They can be approximately cylindrical, narrow bottle-shaped to slightly thread-shaped, tapering towards the front to clearly pointed, smaller specimens usually tapering towards the front, but are rounded at the extreme end. The ventral side is S-shaped, the left and right side in well-fed specimens slightly to strongly convex . The cells often bend back, which can make them appear banana-like. On the sides they are flattened, especially in the front section. The cells move quickly and in a spiral, but rotating wobbly along their longitudinal axis, they only rest briefly while they are eating.
The pellicle is firm and covered with closely spaced, 2 to 3 micrometer long extrusomes . The clearly recognizable cytostome is embedded deep in the cell. The mouth region measures 2/5 to 1/2 of the total length of the cell, in its rear part there is a spacious and bag-like, protruding buccal cavity with sloping, protruding lines.
Due to numerous granules (possibly inactive food vacuoles ) and inclusions, the cell is colored dark gray to black. The cytoplasm contains numerous red, reddish brown, or light orange, speckled or irregularly shaped pigments that are speckled or completely irregular in shape. In slim and small specimens, however, the cells can also be colorless to grayish or even transparent, with a few to many spheres and many short, rod-shaped crystals around 1 micrometer long. The few and (as far as can be proven) large food vacuoles contain equal parts of flagellates and bacteria . In the event that the cells are filled with granules, it is not possible to see food vacuoles. At the end there is a small contractile vacuole that contracts every 3 to 4 minutes. The large nucleus , located in the middle along the main axis of the cell, is ribbon-shaped, slightly to severely twisted and with several, tightly attached oval small nuclei .
The cilia on the cell body is between 7 and 10 micrometers long, the tail eyelash measures 12 to 15 micrometers. The three clearly recognizable membranous cells and membranes of the oral cavity are 10 to 15 micrometers long. The membrane cell (M1) facing the oral cavity extends to the extreme end of the cell, the second membrane cell, which differs only slightly from M1, is composed of 15 to 20 longitudinal rows; the third membranelle is divided into two parts, consisting on the left of 10 rows of basal bodies , on the right of 3 rows extending to the cytopharynx . The paroral membrane to the right of the buccal cavity, which runs slightly obliquely to the main axis, is L-shaped. The scutica consists of around 15 basal bodies loosely arranged in a row.
Dense basal bodies form an average of fifty somatic kinets from mostly one, rarely two kinetosomes ; the number may fluctuate due to the respective physiological condition. The left and right anterior kinets each run from pole to pole of the cell, those on the back break off towards the front end, resulting in a bare, narrow zone.
Ecology and diffusion
Porpostoma notatum is a marine species. So far it could be found in the Southern Ocean , the Atlantic, the North Sea, the Baltic Sea, the Mediterranean and the Pacific (coastal waters near Qingdao , here with a salinity of around 31% and a pH value between 7.9 and 8.0) can be found.
Systematics
The species was first described in 1888 by Karl August Möbius using an example from the port of Kiel. An important synonym is Helicostoma notata . Porpostoma notatum is the only species in the genus besides Porpostoma grassei . Important diagnostic features are the shape of the large nucleus ( oval in Porpostoma grassei ) and the shape of the third membrane ( not divided into two parts in Porpostoma grassei ).
meaning
In coral aquariums, Porpostoma notatum can trigger what is known as Rapid Tissue Necrosis or Brown Jelly Disease , presumably due to incorrect posture, in which stony corals in particular can decompose to the skeleton within a few days.
proof
- ↑ a b c d e f g Weibo Song: Morphological and Taxonomical Studies on Some Marine Scuticociliates from China Sea, with Description of Two New Species, Philasterides armatalis sp. n. and Cyclidium varibonneti sp. n. (Protozoa: Ciliophora: Scuticociliatida) In: Acta Protozoologica, 2000, Vol. 39, pp. 313-316
- ^ A b Karl August Möbius: Fragments of an infusarium fauna of the Kiel Bay , Berlin 1888, in: Archive for Natural History, Volume 54, Vol. 1, pp. 90/91
- ↑ David G. Bourne, Holly V. Boyett, Meegan E Henderson, Andrew Muirhead, Bette L. Willis: Identification of a Ciliate (Oligohymenophorea: Scuticociliatia) Associated with Brown Band Disease on Corals of the Great Barrier Reef , In: Applied and environmental microbiology, 2008, Vol. 74, No. 3, pp. 883-888