Salpa
Phylum: Chordata
Sub - phylum: Urochordata
Class: Thaliacea
Order: Hemimyaria
• Marine, free – swimming pelagic thaliacean.
• Life cycle exhibits alternation of generations.
• Sexual phase called Solitaria phase and asexual phase called gregaria phase.
• Atrial and branchial apertures are at the opposite ends.
• Branchial cavity opens to atrium by a pair of large gill slits.
• It is a protogynous hermaphrodite.
• Solitaria phase is represented by Oozoid and gregaria phase by Gonozooid.
• Direct development.