Volvox Colony

A hollow sphere of thousands of cells that rolls through the water/Microscopic Life

Volvox is a genus of freshwater green algae that form spherical colonies of 500 to 50,000 individual cells. Each colony is a hollow ball, with cells connected by cytoplasmic strands and coordinating their flagella to roll the sphere through the water toward light. Volvox is considered a key model organism for studying the evolution of multicellularity, as the colonies show a division of labor: most cells are small somatic cells responsible for movement, while a few larger cells (gonidia) specialize in reproduction. Daughter colonies form inside the mother sphere and are eventually released when the parent colony breaks apart.