Form of Balanoglossus
These are free swimming animals. Larval stage tailed, with elongate envelope and intermediate vesicle between tail and cephalo-enteron. They have an oral and atrial (cloacal) siphon that are located either opposite. Tunicates are bilaterally symmetrical, at least during the early developmental stages. They possess a pharynx with gill slits, a dorsal neural tube, and a notochord that disappears with development. digestive tract U-shaped, anus located more ventrally than the entrance of the esophagus, fixation peduncle slender, without expansions. Neural ganglion at Gill-septum is slightly arched, extending dorsally and ventrally its posterior bend extended With 10 to 14 pairs of gill-slits.