Chaos (genus)

Lore & Background

Members of this genus closely resemble those of the genus Amoeba and share the same general morphology, producing numerous cylindrical pseudopods, each rounded at the tip. However, while Amoeba have a single nucleus, Chaos can have as many as a thousand. Because of this attribute, C. carolinensis was once placed in the genus Pelomyxa alongside the giant multinucleate amoeba Pelomyxa palustris. Molecular phylogenetic studies have confirmed that it is more closely related to Amoeba than to Pelomyxa. The species is now placed in the independent genus Chaos, a sister group to Amoeba.

Reader's Guide

Chaos species are versatile heterotrophs, able to feed on bacteria, algae, other protists, and even small multicellular invertebrates. Like all Amoebozoa, they take in food by phagocytosis, encircling food particles with their pseudopodia, then enclosing them within a food ball, or vacuole, where they are broken down by enzymes. The cell does not have a mouth or cytostome, nor is there any fixed site on the cell membrane at which phagocytosis normally occurs. Movement is achieved by extending pseudopodia; as a new pseudopod is extended, a variable zone of ectoplasm forms at the leading edge and a fountaining stream of endoplasm circulates within.

Did You Know?

• Chaos carolinensis was once placed in the genus Pelomyxa due to its multinucleate nature.
• The genus Chaos has had a confusing history, with names including Volvox chaos, Chaos chaos, and Pelomyxa carolinensis.
• Chaos species can have up to a thousand nuclei, unlike the single nucleus of Amoeba.