Microworld

world of amoeboid organisms

Menu
Haplomyxa
Fig. 1: Main cell body of specimen A, partly hidden by debris

Haplomyxa sp.

Three specimens were observed in a Petri dish, along with two specimens of an unidentified organic-walled foraminifer resembling a Lieberkuehnia or Claparedellus species. These three specimens were difficult to observe because they were hidden and attached to debris. Only the pseudopodial network was visible. A part of the cell mass of one specimen was visible; it was sausage-shaped and an estimated 600 µm long (fig. 1). A second and much smaller specimen emerged from the debris and extended to the bottom of the dish with some very long granuloreticulopodia (Fig. 2-4). Unfortunately, the stretched cell returned to the debris within minutes and was hidden again. Only a few long strains of granuloreticulopodia remained visible. A third, and also a small one, was also hidden by debris (Fig. 6). It showed a very large network of extremely fine pseudopodia (Fig. 5; video).

I found this naked foraminifer in material scraped from submerged basalt blocks at the foot of the northern dike of Gooimeer (Lake Gooi), Netherlands, May 2020 (52° 18’17.7 “N 5° 18’51.6” E). The material was divided into 40 Petri dishes. Foraminifera were present in only one Petri dish, three naked and two organic-walled. Two naked specimens were isolated, transferred to 50 µl Guanidin each and sent to Maria Holzmann in Geneva for phylogenetic analysis. Both specimens were found to belong to the genus Haplomyxa. The third specimen was lost and could no longer be found.

Haplomyxa
Fig 2: Specimen B. The cell body is hidden by and attached to debris; some pseudopodia are arrowed
Haplomyxa
Fig 3: Specimen B. The cell has left the debris, forming a reticulate plasmodium
Haplomyxa
Fig 4: Specimen B. The cell stretched out as a network with some long granuloreticulopodia
Haplomyxa
Fig 5: Specimen C. Detail of very fine network (image inversed for better visibility)
Haplomyxa
Fig 6: Specimen C. The cell body is surrounded by debris. The pseudopods can easily break off from the main body if there is even a slight movement of the water, for example when the Petri dish is shifted.
Haplomyxa
Fig 7: This Haplomyxa species was collected between these basalt blocks at the base of a dike.
Reticulomyxa
Fig 8: Lake Gooi, the Netherlands
Recent posts

Penardochlamys arcelloides

P. arcelloides – from Penard, 1904 Penardochlamys arcelloides  (Penard, 1904) Deflandre, 1953 Diagnosis: Colorless or very slightly yellowish envelope, bag or cauldron-shaped, very thin, chitinous,

Read More »

Reticulomyxa hannae

R. hannae, plasmodium – photomicrograph Steffen Clauss Reticulomyxa hannae Völcker and Clauß, 2020 Diagnosis: Trophozoites surrounded by a very thin mucous envelope, with slowly moving plasmodia, variable

Read More »

Velamentofex saxonensis

V. saxonensis, feeding (photomicrograph Steffen Clauss) Velamentofex saxonensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 30-95 μm, granuloreticulopodia up to 1000 μm long. with a hyaline, thin

Read More »

Velamentofex tyrolensis

V. tyrolensis (photomicrograph Steffen Clauss) Velamentofex tyrolensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 98-125 μm, with reticulopodia up to 300 μm long, with a hyaline,

Read More »

Velamentofex berolinensis

V. berolinensis Velamentofex berolinensis Völcker and Clauß, 2020 Diagnosis: Trophozoites ovoid, 50-300 µm, with a hyaline, extremely flexible, membranous test. Nuclei numerous, 11.6-16.2 µm in diameter,

Read More »

Lieberkuehniidae

 Lieberkuehniidae  Siemensma, Holzmann, Apothéloz-Perret-Gentil, Clauß, Voelcker, Bettighofer, Khanipour Roshan, Walden, Dumack and Pawlowski, 2020 Diagnosis: Multinucleate organic-walled monothalamous foraminifera. Test very flexible, elongated to broadly

Read More »