Adineta steineri Bartos 1951
Adineta steineri: dorsal view. The last segment of the trunk is wider (bolster) and suddenly narrows foot-wise. The spurs are horn-like and curved backwards.
Adineta steineri; this species has a single thick bristle on each side of the lateral protrusions (although the bristle can break up into several if there is shortage of oxygen under the cover slide), which is in contrast to Adineta barbata (which has several bristles).
Adineta steineri; focus on the head and rostrum.
Adineta steineri; two aspects of the head: left image: dorsal side with focus on the relative thick bristles (in contrast to Adineta sp.6, which has no bristles or only very short ones); right image: focus on the ventral side with focus on the ciliated field. (25.10.2010)
Adineta steineri; two aspects of the head: the arrows point to some circular structures of unknown funktion, which can also be found in A. vaga major and A. rhomboidea.
Adineta steineri; Left image: focus plane on the 9 "U-hooks" which are at the base of the teeth and function as reinforcement.
Adineta steineri; detail of the rake apparatus with 9 U-hooks in each blade; different focus planes (5).
Adineta steineri; specimen from Hattingen-Oberstueter, tree moss (3.2.2013); ventral view on prehensile apparatus, which is partly contracted. Because of the DIC the ciliary field is out focus in this image. (4)
Adineta steineri; the arrowheads point to the nuclei of the paired ovaries.
Adineta steineri; specimen from (3).
Adineta steineri; specimen from (6). Focus plane on the dorsal base of the ciliated field.
Adineta steineri; specimen from (6). Some structures of unknown function in the rostrum.
It seems that the thick conspicuous bristles beneath the "auricles", which are characteristic for A. steineri, are very susceptible to changes of environment, as they start to desintegrate (arrow) very fast while being observed (lack of oxygen?). This might be the reason why DONNER (1965) asked if a specimen (with the habitus of A. steineri) without the bristles might be a new species.
Adineta steineri; frontal view of the head; specimen from (7).
There are habitats where at least two species of Adineta may occur at the same time. Silhouettes (created with Adobe Photoshop) showing two specimens of different groups of Adineta occuring in the same habitat. Upper: A. barbata; lower: Adineta steineri (24.2.2013). A. steineri has a bolster on 1st rump segment, A. barbata does not. See also the differences in the rostrum shape!
location : Gevelsberg, Schulzentrum, oak tree (1); NSG Bourtange/ Bargerveen (3); Hattingen Oberstüter, forest(4); Hattingen Oberstüter, garden (5); Schliersee, Bavaria, (6); Arnsberger Wald, Kapellenplatz (7)
habitat: moss on tree (1); Sphagnum (3); moss epiphytic on treee (4); moss epiphytic on apple tree (5;) moss on tree (6); Trentepohlia-Aufwuchs on fir-tree(7)
Date: 31.3.2006/ 29.10. 2008 (1) 13.11.2012 (2); 27.11.2012 (3); 03.02.2013 (4); 3.10.2016 (5); 10.07.2018 (6); 08.11.2018 (7)
Identification by courtesy of Nataliia Iakovenko, University of Ostrava, Czech republic
freshwater life
marine life