Actinosphaerium

[Carsten Wieczorrek]

Hallo,

in dem Sediment einer meiner Moorproben ist dieses Sonnentier sehr häufig. Ich finde es aber nur in einer Probe. Die Tierchen sind bei mir etwa 450 µm groß. Meine Frage ist, wie wird die Beute gefangen? Ich habe dazu zwar etwas gelesen, aber wie schnell ist diese Ausbildung der Fressvakuole? Ich frage, weil in diesem Tierchen hier zahlreiche Vakuolen noch lebende, sich bewegende, gegen die Vakuolenwand schwimmende kleine Zillialten enthielten. Wie fängt man so ein schnelles Wimperntier? Bis auf Vakuolen, die sich nach außen entleeren, habe ich noch KEINE Bewegung dieser Sonnentiere gesehen.

Schöne Grüße
Carsten

Bild 1 : 6,3 Apo



Bild 2 : 16 Apo



Bild 3 : Ziliat im inneren, 40er Apo

[JB]

Hallo Carsten,

Wenn Sie die Axiopodien bei hoher Vergroesserung beobachten, dann koennen Sie die Bewegung von Organellen entlang der Axiopodien verfolgen https://www.youtube.com/watch?v=HZXPi5tYnbA

"Using its microtubule-containing axopodia, a heliozoan Echinosphaerium nucleofilum feeds on various kinds of protozoans and small metazoans. The present study revealed that food capture and ingestion were carried out in 2 different ways or by a combination of them. The first one was by the rapid contraction of axopodia, by which the food organism was conveyed directly toward the body surface. After such a contraction, many of the microtubules which had been present inside the axopodia degraded and were replaced by C-shaped microtubules. Bundles of tubular bodies were also detected alongside the axonemal microtubules, especially following the use of glutaraldehyde fixative containing ruthenium red. The second method was by means of axopodial flow, by which a food organism attached to an axopodium was conveyed to the body surface along the axopodial surface without accompanying axopodial degradation or contraction. Subsequently the food organism was surrounded by several small pseudopodia to form a food vacuole; many filamentous structures (5-10 nm in diameter) were observed inside the pseudopodia. During the ingestion process many cytoplasmic extensions, including rosary-like filaments, were observed to protrude from the contracted axopodia and the cell body. Mottled dense granules were observed to be discharged from the axopodial surface just when the prey was captured."
http://www.ncbi.nlm.nih.gov/pubmed/7400244

[Carsten Wieczorrek]

Danke.  Das versuche ich heute mal.
Carsten