Question

what are the special features of protochordatagive some examples

Answer 1

Phylum chordata of animal kingdom is divided into 2 sub-groups protochordata/acraniata(without brain box or cranium) and euchordata/craniata( cranium is present).


Again protochordata is divided into two sub-phylum urochordata/tunicata (notochord is present only in larval tail, eg. Salpa,doliolum) and cephalochordata (notochord extends from head to tail region, eg. Branchiostoma)


Elastic, solid, ensheathed rod-like structure of vacuolated turgid cells callled notochord is present may be through out the life or only during early embryonic development mentioned above.


Their central nervous System is dorsal,hollow and single which is different from non-chordata as their CNS is ventral,solid and double.



Ventral heart is present and gut lies ventral to nerve cord.


Post-anal tail is present and if present then it's for balancing.


They are bilaterally symmetrical, triploblastic, coelomate with organ system level of organisation.