Foraminifera d'Orbigny 1826


Foraminifera live in marine and brackish water, but some members of this phylum can be found in fresh water, submerged mosses, sediments, and also in mosses growing on soil and walls. These species seem to be rare, only a handful of people ever found one, despite of their relatively large size. Usually the amoebae spread out their pseudopodial network when kept on microscope slides in moist chambers.


Diagnosis: Filopodia with granular cytoplasm, forming branching and anastomosing network (reticulopodia); bidirectional rapid (10 mm/s) transport of intracellular granules and plasma membrane domains; tubular mitochondrial cristae; fuzzy-coated organelle of unknown function in reticulopodia; polymorphic assemblies of tubulin as (i) conventional microtubules singly or in loosely organized bundles, (ii) single helical filaments, and (iii) helical filaments packed into paracrystalline arrays; majority of forms possess a test, which can be organic walled, agglutinated, or calcareous; wall structure in naked and single-chambered forms quite variable for €œnaked€ athalamids, such as Reticulomyxa, thicker veins vested with an amorphous, mucoid material; for thecate (soft-walled) species, such as members of the genus Allogromia, proteinaceous with little or no foreign material; for agglutinated species, foreign materials bound with an amorphous or fibrous organic matrix; for multi-chambered (polythalamous) forms, walls containing agglutinated material or mineralized with calcite, aragonite, or silica; life cycle often comprising an alternation of asexually reproducing agamont and sexually reproducing gamont.


Allelogromia squamosa

Lacogromia cassipara