Stalked Ascidian, Clavelina robusta
The Stalked Ascidian (Clavelina robusta), is a species of sea squirt in the genus Clavelina (little bottles). It is found in the Western Pacific, Australia, Indonesia, Philippines, Japan and the Solomon Islands. Like all ascidians, this is a filter feeder.
This species is commonly found living in large clusters. It has large 0.8 to 1.5 inch cylindrical zooids. This creature ranges from black to dark blue to gray in color, with individual zooids having fluorescent green, yellow, or white rings around both siphons. The external cover has a firm basal (primitive) matrix, and is somewhat transparent and soft.
Image Caption: Two species of colonial tunicates. Clavelina robusta black and white. Clavelina flava orange. Credit: Nhobgood/Wikipedia(CC BY-SA 3.0)