Radiolarian - Cyrtolagena laguncula 

Although it seems a beautiful glass bottle, it is a radiolarian, a tiny marine protozoan that measures less than one millimeter. Radiolarians are single celled, but quite complex, sophisticated organisms. They form intricate, mineral structures or skeletons (test). This one in the photo, scientifically named Cyrtolagena laguncula, is from the South Atlantic, and has long, slender, conical test made of pure opal, with 7-10 or more annulated joints; the maximum length of test is 144-185 µm.

[Protoctista - Actinopoda - Polycystina - Nassellaria - Theoperidae - Cyrtopera - C. laguncula]. This species was previously named Cyrtopera laguncula.

References: [1] - [2] - [3] - [4]

Photo credit: ©Wim van Egmond 

Physarum polycephalum

….is a species of slime mold that inhabits cool, moist areas like decaying leaves and logs. P.polycephalum is typically yellow in color and lives on a diet of fungal spores, bacteria and various other microbes. P.polycephalum starts out its life in the palsomodium stage, in which it consists of networks of protoplasmic veins and nuceli and will search for food. As its food supply starts to run out the plasomdium will stop feeding and begin its reproductive phase. Stalks will form and release spores.

P.polycephalum is a model organism and has been involved in many studies involving its movement. P.polycephalum has been shown to exhibit astounding intelligent characteristics similar to those of eusocial insects, they have even solved mazes and anticipated events.



Image: Jerry Kirkhart


Alphonse Laveran - Scientist of the Day

Alphonse Laveran, a French physician, was born June 18, 1845. In 1880, Laveran discovered, in the red-blood cells of human victims of malaria, the parasitic protozoan that causes the disease. Protozoa had been known ever since Leeuwenhoek in the 1670s, but, until Laveran, no one had ever associated a protozoan with a human illness. Since he could not find the parasite (soon to be called Plasmodium) in the soil or in the water, Leveran assumed that it was carried by a biting insect, probably a mosquito, and this suspicion would be confirmed by Ronald Ross in 1898. Laveran went on to pioneer the field of medical protozoology, and in 1904 he wrote a comprehensive book on parasitic diseases, which at that time included malaria, sleeping sickness, and kala-azar. Chagas’s disease, which probably afflicted Charles Darwin, would be added to the list in 1909. Laveran received the Nobel Prize in Medicine/Physiology in 1907 “in recognition of his work on the role played by protozoa in causing diseases”. Oddly, Ronald Ross, who relied on Laveran’s work in isolating Plasmodium in the Anopheles mosquito, beat Laveran to the trophy case, receiving the 1902 Nobel Prize in Medicine. But then, it was Ross’s discovery that allowed malaria to be combated, so perhaps the order of awards is the proper one.

The images show a smear of red blood cells infected by Plasmodium, and a portrait of Leveran that is included on the Nobel Prize website.

Dr. William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor, Department of History, University of Missouri-Kansas City


I don’t know the species of this protozoan.
ID anyone?

And I believe it pooped. Naughty little one…

#Biology #Zoology #Protozoology #Invertebrates #Protozoa

Freshwater ciliate Colpidium campylum (400x) 

These are freshwater ciliates of the species Colpidium campylum, characterized by its kidney-shaped cell. The cilia of this protozoan are arranged in rows, and inside you can see the two nuclei that are characteristic of many other ciliates, a more or less central macronucleus, and one micronucleus, slightly smaller.

Because it feeds on bacteria, Colpidium campylum is a microorganism involved in the process of self-purification of water. When the concentration of bacteria is very high in the water, and consequently food is abundant, the population of this protozoan multiplies. So, this species is regarded as a test-microorganism and is used in bioassays with a broad range of applications for single toxicants and contaminant mixtures, such as effluents.

[Protozoa - Ciliophora - Hymenostomatida - Tetrahymenidae - ColpidiumColpidium campylum Stokes]

Technique: Interference Contrast.

References: [1] - [2] - [3]

Photo credit: ©Proyecto Agua | Locality: from a water sample collected in the Ebro river as it passes through Logroño river, La Rioja, Spain (2008)

Slime mold - Hemitrichia clavata

These are sporulating fruiting bodies of the Myxomycete (slime mold) Hemitrichia clavata growing on an old soaked log (Salix). This slime mold grow on rotten wood and is widely distributed throughout the world (North and South America, Europe, Asia: China, Japan, Taiwan).

[Protozoa - Myxomycota - Myxomycetes - Trichiales - Trichiaceae - Hemitrichia - H. clavata]

References: [1] - [2] - [3]

Photo credit: ©André De Kesel | Locality: Boom, Antwerp, Belgium (2012)


Vorticella (Peritrichida - Vorticellidae) is a fresh water protist (protozoan) belonging to the Phyllum Ciliophora. It is a very interesting, stalked ciliate with an inverted bell shape.

Normally, there is a wreath of feeding cilia at the unattached end of the cell, and these create a water current from which small particles of food (mostly bacteria) can be removed and ingested.

Although solitary, they often occur in groups to form a tiny jelly-like mass just visible to the naked eye. 

References: [1] - [2]

Photo credit: ©Frederic Labaune

Locality: unknown