Tectofilosid
Encyclopedia
The tectofilosids or amphitremids are a group of filose amoeba
e with shells. These are composed of organic materials and sometimes collected debris, in contrast to the euglyphid
s, which produce shells from siliceous scales. The shell usually has a single opening, but in Amphitrema and a few other genera it has two on opposite ends. The cell itself occupies most of the shell. They are most often found on marsh plants such as Sphagnum
.
This group was previously classified as the Gromiida or Gromiina. However, molecular studies separate Gromia
from the others, which must therefore be renamed. They are placed among the Cercozoa
, and presumably developed from flagellate
s like Cryothecomonas, which has a similar test. However, only a few have been studied in detail, so their relationships and monophyly are not yet certain.
Amoeboid
Amoeboids are single-celled life-forms characterized by an irregular shape."Amoeboid" and "amœba" are often used interchangeably even by biologists, and especially refer to a creature moving by using pseudopodia. Most references to "amoebas" or "amoebae" are to amoeboids in general rather than to...
e with shells. These are composed of organic materials and sometimes collected debris, in contrast to the euglyphid
Euglyphid
The euglyphids are a prominent group of filose amoebae that produce shells or tests from siliceous scales, plates, and sometimes spines. These elements are created within the cell and then assembled on its surface in a more or less regular arrangement, giving the test a textured appearance...
s, which produce shells from siliceous scales. The shell usually has a single opening, but in Amphitrema and a few other genera it has two on opposite ends. The cell itself occupies most of the shell. They are most often found on marsh plants such as Sphagnum
Sphagnum
Sphagnum is a genus of between 151 and 350 species of mosses commonly called peat moss, due to its prevalence in peat bogs and mires. A distinction is made between sphagnum moss, the live moss growing on top of a peat bog on one hand, and sphagnum peat moss or sphagnum peat on the other, the...
.
This group was previously classified as the Gromiida or Gromiina. However, molecular studies separate Gromia
Gromia
Gromia is a widespread genus of marine and freshwater amoeboids, closely resembling some foraminiferans. It produces an organic test, which is ovoid or lobed and may exceed one millimetre in size; this resembles a small grape, in that its centre is fluid-filled but lacks organic matter, which is...
from the others, which must therefore be renamed. They are placed among the Cercozoa
Cercozoa
The Cercozoa are a group of protists. They are sometimes described as a kingdom.-Characteristics:The group includes most amoeboids and flagellates that feed by means of filose pseudopods. These may be restricted to part of the cell surface, but there is never a true cytostome or mouth as found in...
, and presumably developed from flagellate
Flagellate
Flagellates are organisms with one or more whip-like organelles called flagella. Some cells in animals may be flagellate, for instance the spermatozoa of most phyla. Flowering plants do not produce flagellate cells, but ferns, mosses, green algae, some gymnosperms and other closely related plants...
s like Cryothecomonas, which has a similar test. However, only a few have been studied in detail, so their relationships and monophyly are not yet certain.