Balanoglossus is a long cylindrical worm like hemichordate animal. It lives in burrows in the sand of intertidal region.
- It will cover and protect the body organs.
- It will secrete slime which helps the animal to move in the burrows.
- It will absorb the external stimule.
- It will help in locomotion.
- Stomochord: It is present in the proboscis. It gives strength to proboscis. It is formed as an extension of Buccal epithelium. This stomochord includes a central cavity. It is considered as a homologous organ with notochord of chordales.
- Branchial skeleton: The gill pouches are supported by chitinous structures. They are primary gill bars and secondary gill bars.
- Pygochord: On the ventral sideof the gut a longitudinal pygochord is present. Its function is not clearly known.