In Urochordata

Correct option is C

Correct Answer: C. Notochord is present only in larval tail region

• Urochordata (also called Tunicata) is a subphylum of Chordata.

• In larval stage, Urochordates show all chordate features:

  • Notochord (in the tail region only)

  • Dorsal hollow nerve cord

  • Pharyngeal gill slits

  • Post-anal tail

• However, in adult stage, they become sessile (non-motile) and lose the notochord and most chordate characteristics.

• Examples: Ascidia, Salpa, Herdmania

• Urochordata vs Cephalochordata:

  • Urochordata: Notochord in larval tail only

  • Cephalochordata: Notochord extends throughout life and entire body