Question

Give the character of phylum hemichordata.

Answer 1

Hint: Hemichordata is a subphylum of phylum Chordata, that belongs to the animal kingdom. Animals of such phylum show some similarities with Chordata animals. In 1995 this phylum was grouped under non-Chordata and named hemichordate.

Complete answer:
Hemichordates are exclusively marine and live in burrows due to tubulous. The body is soft and looks like a worm that is divisible into proboscis, collar, and trunk. They can be solitary or live in colonies.
Hemicordate is enterocolitis and the body wall is the single-layered epidermis. They show bilateral symmetry and triploblastic animals.
The digestive tract is complete and gills slits are present with the pharynx, gills slits are dorsal in position but lateral in chordates. Respiration takes place through the branchial portion of the pharynx, which holds gills slits.
The blood vascular system is the open type with colourless blood and contractile heart vesicles, two longitudinal vesicles one is dorsal and one is ventral.
The excretory organ is associated with proboscis gland or glomerulus which is located in the proboscis.
The nervous system is a primitive type that consists of intraepidermal nerve plexus, an epidermal cell that has a sensory cell that acts as a sensory organ. Reproduction is majorly sexual and sexes are separate or united and fertilization is external. The development process is mostly indirect through free-swimming larva (tornaria larva), except for a few species.

Note: Hemichordata phylum is further subdivided into two classes. Enteropneusta includes acorn worms that have a vermiform body and found near seas on sandy beaches in a warm climate.