Volvox carteri[1] is a species of colonial green algae in the order Volvocales.[2] The V. carteri life cycle includes a sexual phase and an asexual phase. V. carteri forms small spherical colonies, or coenobia, of 2000–6000 Chlamydomonas-type somatic cells and 12–16 large, potentially immortal reproductive cells called gonidia.[3] While vegetative, male and female colonies are indistinguishable;[4] however, in the sexual phase, females produce 35-45 eggs[4] and males produce up to 50 sperm packets with 64 or 128 sperm each.[5]
The genome of this species of algae was sequenced in 2010.[6]Volvox carteri is a significant model organism for research into the evolution of multicellularity and organismal complexity, largely due to its simple differentiation into two cell types, versatility in controlled laboratory environments, and natural abundance.[7]