Asexual Reproduction `:` It takes place through formation of zoospores, palmella state, aplanospores, hypnospores and akinetes.
(i) Zoospores `:` They are flagellated spores which are formed under favourable conditions. A fully grown parent cell comes to rest and withdraws flagella. Protoplast of parent cell divides into 2-16 daughter protoplasts. Each daughter protoplast secretes cell wall and develops flagolla to become zoospore. Wall of the parent cell breaks and the zoospores are liberated. Zoospores develop into adult.
(ii) Palmella stage `:` In the present of excess salts, toxic chemicals, the Chlamy-domonas is surrounded by mucllaginous cell wall. It withdraws flagella. The non motile naked alga start to grow and divide to form a number of cells. These naked cells are called palmellaspores. Each palmellaspore develops flagella and cell wall to become normal individual.
(iii) Aplanospores `:` Under drought condition, the protoplasts of an individual alga contracts, rounds off and secrets a thin wall to become an aplanospore. For Example `:` Chlamydomonas caudata. Aplanospore are released after the decay of the parent cells. It germinates under favourable conditions to produce a new individual.
(iv) Hypnospores `:` They are thick walled spores which are formed like aplanospores. Hypnospores often contain a reddish carotenoid pigment, called haematochrome.
(v) Akinetes `:` Under long unfavourable conditions, the individual palmellaspore secrets thick walls to produce resting spores , called akinetes.
