Kingdom: Animalia

Phylum: Chordata

Class: Ascidiacea

Order: Stolidobranchia

Family: Pyuridae

Genus: Boltenia


This egg-shaped sea squirt is easily recognized by the branched tentacles giving it a cactus-like appearance. The diameter can reach 45 mm, 35 is more common. The color is usually yellow or light brown, sometimes with a tint of red or green. The test is thick and leathery, bearing radially branched spines. Both siphons 4-lobed and placed at the top. From 12-16 branched branchial tentacles of variable size. Branchial sac with numerous rows of straight and transversal orientated stigmata; six branchial folds per side; eight longitudinal bars per fold. Gut left of branchial sac; stomach narrow and small, not marked off from the rest of the gut but with many diverticula forming a complex liver. One long and lobed gonad on each side