Lüsosoomides

Lüsosoomides is a genus of unicellular eukaryotic protists characterized by abundant lysosome‑like organelles that function in intracellular digestion. Members are free-living and aquatic, found in freshwater and brackish habitats and occasionally in moist soils. They are heterotrophic and feed on bacteria and small eukaryotes by phagocytosis.

Morphology: Cells are typically 8–25 μm, nearly spherical to oval, with a flexible membrane. The cytoplasm contains numerous vesicles resembling lysosomes, a single nucleus, and an often conspicuous contractile vacuole. Motility is primarily amoeboid; some species form short pseudopodia during feeding.

Life cycle: Reproduction is predominantly asexual by binary fission; encystment occurs under desiccation or nutrient limitation. Rare reports of sexual processes exist but remain unconfirmed.

Ecology and distribution: Lüsosoomides appears cosmopolitan in temperate regions, with recordings in lakes, rivers, wetlands, and occasionally soil moisture. In ecosystems, they contribute to bacterial turnover and form part of the microbial predation landscape in freshwater systems.

Taxonomy and phylogeny: The genus is placed within an uncertain lineage of amoeboid protists; 18S rRNA analyses tentatively position it near Amoebozoa, but relationships require further data. The type species is Lüsosoomides aquaticus; the genus currently comprises at least two described species.

Etymology and naming: The name derives from lysosome-like digestion structures and the Greek suffix -ides, with the umlauted initial indicating its distinct spelling.