Genus Lecythium

Lecythium hyalinum with large nucleus

Diagnosis: test round, lenticular or pyriform, a highly flexible, colorless, hyaline membrane that follows the size changes of the cytoplasma during feeding or starvation; aperture usually between folds and flexible; plasma fills the test completely; nucleus vesicular or ovular; filopodia usually few, long and straight.

Dimensions: mostly small species.

Ecology: common in different types of water; feeding on algae and bacteria.

Remarks: Nucleus and pseudostome are difficult to observe, the latter is usually a small slit between folds.

Three observed species:

• Lecythium hyalinum
• Lecythium granulatus
• Lecythium spinosum