Significance of retrogressive metamorphosis in ascidia
Answers
Retrogressive metamorphosis:
Retrogressive metamorphosis is the reverse of metamorphosis. In retrogressive metamorphosis an advanced larval form of Ascidia with developed structures gradual loses them in the adults to form a sessile adult animal with primitive structures. This process is peculiar and uncommon in that is form a degenerated adult from a complex and organized larva.
The significance of this process lies in,
(i) Developing the adult Ascidia which perform minimum functions in their adult stages and hence unnecessary advanced structures of the larva are lost to reduce energy expenditure in maintaining them.
(ii) Ensuring the development of a degenerated adult that do not contain the larval structures which are required in the agile larvae but no in adults.