Question

Short answer question.

Explain the different methods of reproduction occurring in sponges.

Answer 1

• Asexual reproduction in sponges:

1. Sponges reproduce asexually via. gemmule formation. Gemmule is an internal bud formed only in sponges to overcome unfavorable conditions.
2. The structure of the gemmule includes the micropyle, spicule, inner layer, archaeocytes, and outer layer.
3. It possesses an asexually produced mass or aggregation of dormant cells known as archaeocytes. These cells are capable of developing into a new organism (totipotent).
4. The archaeocytes get coated by a thick resistant layer of secretion by amoebocytes.
5. Monaxon spicules (developed by growth along a single axis) are secreted by scleroblasts in between the inner and outer membrane.
6. On return of favorable conditions of water and temperature, the gemmules hatch and develop into a new individual.
7. There is a minute opening called micropyle through which the cells (new individuals) come out during favourable conditions.

• Sexual reproduction in sponges:

1. Poriferans that reproduce by the sexual method are hermaphrodites and produce sperms and eggs at different times.
2. Sperms disseminated into the water column, are subsequently captured by female sponges of the same species.
3. Inside the female, the sperm is transported to eggs by means of archaeocytes.
4. Fertilization occurs and zygotes develop into ciliated larvae.
5. Once these larvae are in the water column, they settle and develop into juvenile sponges.