Carpogonium

Carpogonium

Illustration of Collema crispum, a lichen with a visible carpogonium.

The carpogonium is a specialized structure found in certain groups of algae and fungi, particularly within the Rhodophyta (red algae) and some Ascomycota (sac fungi). It plays a crucial role in the reproductive cycle of these organisms, facilitating the process of sexual reproduction.

Structure

The carpogonium is typically a single cell or a group of cells that are differentiated to function as the female gamete. In red algae, the carpogonium is often elongated and contains a trichogyne, a hair-like extension that captures male gametes or spermatia. This structure is essential for the fertilization process, as it allows the non-motile spermatia to reach and fuse with the carpogonium.

Function

In the reproductive cycle, the carpogonium is responsible for receiving the male gametes. Upon successful fertilization, the carpogonium undergoes a series of developmental changes that lead to the formation of a carposporophyte. This structure eventually produces carpospores, which are released to give rise to new individuals, thus completing the life cycle.

Role in Lichens

In lichens, which are symbiotic associations between fungi and photosynthetic partners (usually algae or cyanobacteria), the carpogonium is part of the fungal component. The illustration of Collema crispum shows a lichen where the carpogonium is involved in the sexual reproduction of the fungal partner, contributing to the formation of fungal spores.

Related Pages

• Red algae
• Ascomycota
• Lichen
• Reproduction in algae
• Fungal reproduction