Microworld

world of amoeboid organisms

Menu

Family Mesofilidae Cavalier-Smith and Bass 2009

Diagnosis: Biciliate amoeboflagellates with numerous extremely long branching filopodia that in contrast to Heliomorphidae (Tetradimorpha and Heliomorpha — usually known by the invalid names Dimorpha or Dimorphiella) do not radiate in three dimensions from a centrosome but are appressed to the substratum during feeding. Filopodia and long cilia can be present simultaneously or each on their own, depending on the growth phase.

Type genus Mesofila Cavalier-Smith and Bass 2012

Diagnosis as for family Mesofilidae.

Mesofila limnetica Cavalier-Smith and Bass 2009

Diagnosis: With amoeboid and ciliate phases. Amoeboid cells circular to slightly polygonal, with uneven/pitted surface; 9—14 µm in diameter. Central nucleus about a quarter of cell body diameter, with conspicuous central nucleolus. Branching filopodia issue from all around the cell, sometimes with slightly thicker filopodia emerging bipolarly. Filopodia long, up to 10x cell diameter; or more. Cell body and filopodia remain in contact with the substrate; immotile, except in motile ciliate stage. Filopodia carry evenly and closely spaced prominent granules, and sometimes appear to anastomose. The ovoid ciliate, cell length 8 µm) has two cilia, the posterior trailing and 2-2.5x cell length, the anterior 0.5-1x body length beats vigorously, often curving round on it self. Gliding erratic and swift, with the (thicker) posterior end of the cell raised off the substrate. Ciliate also swims rapidly with a helical motion. Cysts spherical, smooth, refractive; ca. 10 µm diameter. Can grow very densely, especially when bacterial density high, and bacteria accumulate and obscure the cellbody.

Type locality: hotspring with rich organic mud from stream, Palm Canyon, California, United States.

Recent posts

Penardochlamys arcelloides

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

Read More »

Haplomyxa spec

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

Read More »

Lachmannia spec.

“Lachmannia” spec., body length 127 µm “Lachmannia” spec. I found two cells, size about 125 µm when ovoid, with an organic-walled membranous test and a

Read More »

Diplophrys spec. 7

Diplophrys spec., with three tufts of filopodia Diplophrys spec. These cells are granular, never seen before. I found them in a sample from the Bert

Read More »

Psammonobiotus spec.

I found this specimen in a sample from the Oppad, near Hilversum, 2020. It is similar to Psammonobiotus linearis, but lacks a clear spine at

Read More »

Sphenoderia compressa

Sphenoderia compressa, after Badewitz, 2002 Sphenoderia compressa Badewitz, 2002 Diagnosis: Test ovoid, oval in cross section, hyaline, covered with relatively small, oval, rather irregularly arranged

Read More »