Colonial Star Tunicate (Botryllus schlosseri)

Botryllus schlosseri is a colonial tunicate that thrives in stable, well-filtered marine systems. They are filter feeders and require a constant supply of suspended particulate food. Feed them phytoplankton daily or every other day, and remove excess food and debris to maintain good water quality. They attach to hard surfaces like rocks, plastic, or glass and will spread outward as the colony grows. Colonies are made up of many zooids connected by a shared vascular system, so space and stability are important. For breeding, Botryllus schlosseri are simultaneous hermaphrodites and can spawn seasonally in response to changes in temperature and light. Spawning can be induced by gradually raising the temperature by a few degrees and increasing photoperiod. Larvae are brooded inside the colony and released as free-swimming tadpole larvae; provide clean seawater and a hard substrate for settlement. Colonies may also go through natural regression and rejuvenation cycles, so consistent feeding and stable water quality help support continuous growth.