Asplanchna priodonta Gosse 1850
Asplanchna priodonta, whirling, dorsoventral view. (5)
Asplanchna priodonta, whirling, focus plane on the trochus; accompanied by the potential prey, two Keratella rotifers in the same focus, which allows to compare their size.(1)
Asplanchna priodonta, whirling, focus plane on the (pseudo) trochus. SZ: sensory bristles; Oc: ocelli; CA: cerebral eyespot; G: brain; K: trophi; arrowheads: cilia. (1)
Asplanchna priodonta, incudate trophi; Ra: rami;; Fu: fulcrum; Man: manubria; Un: Unci.
Asplanchna priodonta, incudate trophi of a specimen from (4). The inner margins of the rami are dentated (arrows), which is in contrast to Asplanchna girodi.
Asplanchna priodonta, with resting egg (see also images below) . (6)
Asplanchna priodonta, focus plane on the stomach (St); gastric glands (GG); protonephridium (Ne) and lateral antenna (LA). Also visible: Sensory bristles (SB) and cerebral eyespot (Ey). (5)
Asplanchna priodonta, focus plane on the stomach (St), gastric glands (GG), protonephridium (Ne), bladder (Bl) and ovary (Ov).
Asplanchna priodonta, protonephridium. TZ1 und TZ2: terminal cells ; yellow arrowheads: W: ciliary flames; red arrowheads: outer cilia.
nephridium: video
Asplanchna priodonta, two aspects of the same specimen. Upper image: focus plane on the integument proximal to the lens; lower image: focus plane on the integument of the distal side. In contrast to many other rotifer species this Asplanchna ??only this specimen?? has two dorsal antennae (arrows) and two lateral antennae (arrowheads).
Asplanchna priodonta, dorsal antenna (DT). N: nerve cells; A: amoebocytes (see below)
Asplanchna priodonta, the dorsal antenna (DT) is composed of several cells.
Asplanchna priodonta, the lateral antenna consists of a single sensory cell.
Asplanchna priodonta, amoebocytes: the whole pseudocoelom is filled with a net of amoeboid moving cells (amoebocytes). Two images showing the movement of the same cell. video >>>>
Asplanchna priodonta, the amoebocytes have vacuoles that may contain bacteria or substances that have been removed from the liquid of the pseudocoel.
Asplanchna priodonta, ciliated stomach. video >>>>. The stomach ends blind.
Asplanchna priodonta, orientation of the lateral antenna (LA): Ne 1 and Ne 2: protonephridia; stomach (St); bladder (Bl); amoebocyt (Am); nerve cell (N) 16.10.2010
Asplanchna priodonta, male specimen from (3)
Asplanchna priodonta, male specimen; BL: bladder; Pe: penis; arrowheads: accessory glands; the arrows characterize the area of the atypical sperm cells which produce intracytoplasmatic rods (which look like needles in this image). The rods are supposed to assist the sperm cells while penetrating. The sperm cells are labelled with asterisks. The spherical cells might be not fully developed sperm cells.
Asplanchna priodonta, specimen from (7); because A.priodonta is viviparous often there are several amictic eggs in different development stages present in the oviduct.
Asplanchna priodonta, closeup of the above specimen from (7); the egg marked with an asterisk has only a single nucleus while (in counterclockwise direction) the number of nuclei in the embryos is increasing. In the left egg the eyespot of the almost fully developed embryo is visible.
Asplanchna priodonta, upper image: female with resting egg and a male rotifer simultaneously. The conclusion is that two mictic eggs developed in different ways: one mictic egg had been fertlized, resulting in a resting egg; the other mictic egg had not been fertilized, so the result is a male rotifer. (7)
Asplanchna priodonta, crop of the above image. The white arrow points to one of the sperm cells of the male which is in focus. The white arrowheads point to some testicular rods. The yellow arrows point to two of the many nuclei of the resting egg where a grain of unknown function is visible. The nuclei indicate that the resting egg is not a single cell but a developing embryo which later will stop development (diapause).
Asplanchna priodonta, left image: same resting egg, different focus plane. Again the arrowheads point to those nuclei in which nucleoli are associated with a small grain of unknown funktion (which is more visible in full resolution). Right image: another resting egg from the same population; the optical transect inside the shell shows two layers: the outer syncytial layer ( ??ectoderm?? ) is granular and has small nuclei (approx. 8µm; one is marked by arrowheads); the innner syncytial layer (?? entoderm ??) is more smooth and the nuclei are larger (approx. 17µm; one is marked by a double arrow) than the nuclei of the outer layer. It seeems as if the yellow lipid droplets are exclusively located in the outer layer.
Asplanchna priodonta, male specimen from (7). The arrows point to the two lateral antennae.
Asplanchna priodonta, male specimen from (7). optical longitudinal transect showing the reproductive organs.
Asplanchna priodonta, specimen infested by unknown parasites. (8)
Asplanchna priodonta, specimen infested by unknown parasites, probably the same as specimen from location (8). (9)
Asplanchna priodonta, unknown parasites in the vicinity of one of the lateral antennas. Because the opening of the integument (arrowhead) for the sensory cell of the lateral antenna is in focus, it is evident that these parasites are located in within a layer that is close to (or inside) the integument. (8)
Asplanchna priodonta, two images of parasites, different focal planes. Upper image: focal plane on the cell wall of the parasites; lower image: optical median transect of the parasites. (8)
Asplanchna priodonta, two images of a specimen from a different sample (9), presumably infected by the same parasites by infection with water from the 1st sample (8). Some of the parasites are connected by circular structures (arrowheads). Lower image shows one of the lateral antennas (arrow) (8)
Asplanchna priodonta, vertical aspect on the integument shows that the parasites are inside the host (Int: internal; Ext: external). (9)
See also: Asplanchna priodonta var. henrietta
Location (1): Sprockhövel, NRW, Germany; IG-Metall-Bildungszentrum; fire-fighting pond.
Habitat (1): plankton (click image to enlarge >>>)
Date (1): 25.09.2007
Location (8): nature reserve NSG Unteres Odertal; BB, Germany; Mummertgraben
Habitat (8):plankton / "aufwuchs" on artificially exposed microslides
Date (8): 15.05.2023
Location (9): water reservoir Heilenbecker Talsperre; Ennepetal, NRW, Germany
Habitat (9): plankton
Date (9): coll. 29.05.2023 ; img.: 31.05.2023
Location: (5); (7); Hattingen Felderbachtal (3); (4)
habitat: plankton (2); (3); (4); (5); (7);
Date: 18.10.2008 (6); 31.05.2009 (2); 21.09.2014 (3); 14.06.2014 (4); 11.10.2010 (5); 15.04.2020 (7);
freshwater life
marine life