Pretty Protozoa

Ceratochoris horrida (via)

Stentor sp. (via)

A gregarine (via)

Credit: James Marden. The parasite that causes metabolic disorders in dragonflies, as it appears under an electron microscope at 100-micron scale. Known as gregarines, the parasite belongs to Apicomplexa, a group of microorganisms including protozoa that cause diseases like malaria and cryptosporidiosis. (More)

Frontonia mengi (via) (via)

from Fan et al. 2011. Two novel marine Frontonia species, Frontonia mengi spec. nov. and Frontonia magna spec. nov. (Protozoa; Ciliophora), with notes on their phylogeny based on small-subunit rRNA gene sequence data. Int. J. Syst. Evol. Microbiol. 61(6):1476-1486.

natureofnature:

Confocal fluorescence microscopy of mating pairs of Tetrahymena thermophila labeled with antiserum to tubulin (blue), TCBP-25 (red), and sytox nuclear stain (green).

Euplotidium rosati and Euplotidium arenarium (via)

Figure 4-7. Scanning electron micrographs of Euplotidium rosati n. sp. (Fig. 4–6) and Euplotidium arenarium (Fig. 7). 4. Ventral view from the right side, where asterisks indicate frontoventral cirri. 5. Ventral view from the left side to evidence the lack of the left marginal cirrus. 6. Dorsal view. 7. Ventral view of Euplotidium arenarium. This specimen probably lost epixenosomes due to prolonged lab cultivation of the cells (see text). Asterisks indicate frontoventral cirri. DK, dorsal kineties; E, epixenosomes; LMC, left marginal cirrus; PP, peristomial plate; TC, transverse cirri. Bars = 10 μm. (More)

from Modeo et al. 2013. Morphological, ultrastructural, and molecular characterization of Euplotidium rosati n. sp. (Ciliophora, Euplotida) from Guam. J. Eukaryot. Biol. 60(1):25-36.

biocanvas:

Two protozoan parasites, Trypanosoma brucei, are shown infecting the liver of a mouse. T. brucei is the causative agent of African sleeping sickness in humans.

Image by Gilles Vanwalleghem, Daniel Monteyne, Etienne Pays, and David Pérez-Morga, Université Libre de Bruxelles.

nprglobalhealth:

The Twisted Life Of Toxoplasma Gondii

T. gondii has a split personality. Most people who pick up the bacteria protozoan from raw beef or pork show no symptoms at all. But others, can get pretty sick.

T. gondii also has a reputation for making cats crazy.

Here we can see the movement of the parasite filmed under a microscopy. The beautiful patterns show three types of motion:twirling, circular and helical.

Image by James M.McCoy/PlosPathogens

rhamphotheca:

Stentor: What and Where

Although most protozoans are microscopic, the Stentor is the exception to this rule and can be up to 2mm long! It is therefore larger than many of the multi-cellular organisms found in freshwater such as rotifers and water-fleas, and has been known to eat the smaller members of these groups.  Stentor are usually present in most freshwater ponds.

Take a few pieces of the stem of any floating plant (eg. Potamogeton), which has spear-shaped leaves. Place the stems in some water in a shallow dish and allow a few minutes for the water to settle. Examine the stems with a 10x hand lens - any Stentor present on the stem will be visible as long trumpet-shaped organisms. Stentor may also be swimming freely, when they become more oval in shape with a narrowing at their posterior.  

Autumn (the Fall) is a good time of year to find Stentor because leaves falling into a pond increase the bacteria population feeding on the decaying vegetation. This leads in turn to an increase in the population of protozoa such as Stentor which feed on the bacteria.  Colonies of Stentor often occur, in which the lower parts of the animals are covered with a mucilaginous substance which they secrete…

(read more: Microscopy UK)   (image: Proyecto Agua)

scientificillustration:

The Dinoflagellata: the Dinophysoidae by Charles Atwood Kofoid and Tage Skogsberg