Free Floating Sea Squirts

Anatomy of members of the Class Thaliacea showing:  internal structures through transluscent bodies, variation of individual body plans (1, 3, 4, 6, 7 & 8′) and arrangements of colonies (5 & 10).  The general body plan is of seiving structures held within a tubular pharynx where water is funnelled for food, respiration and propulsion.  Note the muscle banding used to create water flow and the centralisation of nervous tissue (labelled N) which is indicative of their place within the Chordata.