Acetabularia
Acetabularia:-
1. Classification:-
DIvision:- Chlorophyta
Class:- Chlorophyceae
Order:- Ulvales
Family:- Ulvaceae
Genus:- Acetabularia
2. Habit and Habitat:-
> Acetabularia, also called mermaid’s wine glass, genus of single-celled green algae found in subtropical seas.
> It is found in shallow temperate and tropical seas.
> It usually grows on pebbles, shells or pieces of rock, and is often found in seagrass meadows, on mudflats and coral reefs, in estuaries and growing on the submerged roots of mangroves.
3. Thallus structure:-
> Acetabularia has an unusual structure by being large, unicellular and possessing features that might be considered organs -‘ roots, stems and leaves’.
> The single cell is attached to the substrate by root-like cellular extensions. These extensions connect to an elongate stalk that ends in an umbrella-like cap which is often 1 cm or more across.
> The single nucleus of this remarkable organism is found at the base of the stem.
> If the stalk is cut it can regenerate a new top and the top can generate a new base, although it is short-lived, presumably because it lacks a nucleus.
4. Reproduction:-
> Sexual reproduction in Acetabularia is initiated when the single (diploid) nucleus goes through multiple mitotic divisions.
> These nuclei subsequently undergo meiosis and migrate to the cap where they are released in cysts that break open to release mobile gametes.
> If these gametes find gametes from another alga they fuse to form a zygote that attaches to a substrate and grows into the mature form.
> Asexual reproduction is also possible if mobile (diploid) zoospores are released and behave like zygotes, attaching to a substrate and developing into the mature form.
