Morphology: Violet Tunicates grow as encrusting tunicates, reaching 2.0 mm to 3.0 mm in thickness. The individual microscopic animals making up the colony are known as zooids. Each zooid has an oral siphon and an atrial canal (opening to a shared cloacal chamber). Each zooid is engulfed in a connective mass called a tunic. The tunic is soft and somewhat fragile. The zooids are arranged in chains, and are easily freed from the tunic. Each zooid has 10 or 11 rows of stigmata and 9 to 12 stomach folds. The Zooids are 2.5 mm in length. Violet Tunicate colonies are of a uniform color and may be brown, cream, lavender, orange, purple, red, or yellow. Their irregularly shaped colonies can reach up to 20 cm (7.9 inches) in length and 2.0 cm (0.8 inches) in width.

Habitat and Distribution: Violet Tunicates grow on hard surfaces such as rock, bivalve shells, pilings, docks, and vessel hulls. They also grow on seaweeds and eelgrasses. In both their native and introduced ranges, they seem to prefer manmade structures to natural substrates. Violet Tunicates live from the lower intertidal zone to around 10 m (33 feet) in depth. They are native to the northwest Pacific Ocean, ranging from Japan to northern China. They have since been introduced to the northeastern Pacific, the northwestern Atlantic, and to a lesser degree, the northeastern Atlantic. They are generally considered to be invasive in these areas. The range of the Violet Tunicates in the Atlantic Ocean including the Gulf of Mexican and the Caribbean is poorly doucmented. In the Pacific Ocean they are are found in all Mexican waters.

Diet: Violet tunicates feed by pumping water into the oral siphon and through finely meshed ciliated gills on the pharynx. The gills filter out phytoplankton and detritus, which are then passed on mucus strings to the stomach and intestines. Once the zooids extract nutrients from the water, they channel the filtered waste streams into large, communal central chambers. The wastewater is then forcefully pumped clear of the colony, ensuring the microscopic filter-feeders do not continuously re-ingest their own expelled water.

Predation: Violet tunicates are preyed upon by crabs, fish, gastropods, crabs, sea stars and sea urchins, though this varies based on location.

Reproduction: Violet Tunicates reproduce both asexually, by budding, and sexually. The zooids are simultaneous hermaphrodites (having both male and female reproductive organs). It seems to be unclear for this species if the eggs are self-fertilized or fertilized by sperm from nearby animals. The eggs are internally fertilized and the embryos are incubated in a brood pouch. The fertilized eggs hatch into larvae with a muscular tail, notochord, eyespots, and a set of adhesive papillae. The larvae swim briefly, usually less than a day, before settlement. Once they mature sufficiently and find the proper habitat, they settle to the substrate, the tail is absorbed, the gill basket expands, and the tunicate begins to feed by filtering water.

Ecosystem Interactions: Violet Tunicates are sometimes epibionts on bivalves and other hard shelled invertebrates. These relationships is commensal with no harm coming to the host organism. Otherwise, there are no documented commensal, mutulastic or parasitic relationships for this species. Where they have been introduced, they strongly compete with other organisms for space. Often times the species impacted are other introduced fouling organisms.

Human Interactions: Violet Tunicates are considered to be fouling organisms. They attach to buoys, chains, lines, pilings, vessel hulls and other infrastructure, adding weight and slowing vessels. In sufficient numbers, they can smother aquaculture farms. They were introduced to non-native habitats via shipping. From a conservation perspective the Violet Tunicate has not been formally evaluated, however, based on their rapid dispersal they appear to be thriving and should be considered to be of Least Concern.

Synonyms: Botrylloides aurantium, Botrylloides carnosum, Botrylloides lateritium, Botrylloides violaceum, and Botryllus aurantius.