Write the general characters of phylum Chordata.

(N/A) $\rightarrow$ Animals belonging to phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsal hollow nerve cord, and paired pharyngeal gill slits.
$\rightarrow$ These are bilaterally symmetrical, triploblastic, and coelomate animals with an organ-system level of organisation.
$\rightarrow$ They possess a post-anal tail and a closed circulatory system.
$\rightarrow$ Phylum Chordata is divided into three subphyla: Urochordata (or Tunicata), Cephalochordata, and Vertebrata.
$\rightarrow$ Protochordates:
$\rightarrow$ Subphyla Urochordata and Cephalochordata are often referred to as protochordates and are exclusively marine.
$\rightarrow$ In Urochordata, the notochord is present only in the larval tail, while in Cephalochordata, it extends from the head to the tail region and is persistent throughout their life.
$\rightarrow$ Examples of Urochordata: Ascidia, Salpa, Doliolum.