• The shells have hundreds of tiny holes called foramen, the Latin word for window. 
• The organism pushes extensions of its cytoplasm called pseudopodia (or false feet) through these holes to gather food.

• Shell (Test) Structure: Most foraminifera produce hard shells called tests, which can be single or multi-chambered. These tests are commonly composed of calcium carbonate (calcite or aragonite), agglutinated sediment particles, or protein. Some species may even lack tests entirely.

• Shell Morphology: Tests vary greatly, from simple tubes or hollow spheres to highly elaborate chambered structures. Shells may be milky white, glassy, or grey depending on their composition and crystallography.
• Pseudopodia: Foraminifera extend granular ectoplasmic pseudopodia through small openings in their tests; these pseudopodia are used for locomotion, food capture, and environmental interaction.
• Cell Structure: The cell is divided into granular endoplasm and transparent ectoplasm, with nuclei that vary in number and size depending on sexual or asexual stages.
• Life Cycle: Foraminifera exhibit alternation of generations with distinct sexual (megalospheric) and asexual (microspheric) forms.
• Size: Typically less than 1 mm but some species can grow much larger, up to around 20 cm.

• Benthic forams: Live on or within the seafloor sediments.
• Planktonic forams: Float in the upper water column of the open ocean. 

• Ecological Role: They play an important role in marine ecosystems as both benthic (bottom-dwelling) and planktonic (floating) organisms, contributing to the marine food web.
• Paleontological Importance: Their extensive fossil record, dating back over 500 million years, is crucial in biostratigraphy and dating sediment layers.
• Climate Studies: Foraminifera shells record past ocean temperatures and chemistry, making them vital proxies for reconstructing paleoclimates and studying climate change.
• Oil and Gas Exploration: Foraminiferal fossils help locate hydrocarbon deposits by indicating ancient marine environments.
• Carbon Cycle Influence: Through their calcite shells, foraminifera contribute significantly to the oceanic carbon cycle, particularly carbon sequestration in marine sediments.

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