Question

Name three sub-phyla of phylum chordata. Write characters and examples of protochordates.

Answer 1

Phylum Chordata is divided into three subphyla, namely Urochordata (tunicates), Cephalochordata (lancelets) and Vertebrata (vertebrates).

General characteristics of Protochordata:

(A) Elastic, solid, rod-like structure of turgid cells called notochord is present.

(B) The central nervous system is dorsal, hollow and single.

(C) The pharynx is perforated by gill slits.

(D) The ventral heart is present and gut lies ventral to nerve cord.

(E) The post-anal tail is present for balancing.

(F) Bilateral symmetry, triploblastic, true coelom present.

Examples: Balanoglossus, Herdmania, Amphioxus.