Because they don't perform photosynthesis, they are actually tiny animals!
The major difference between a sponge and a plant is that sponges do not rely on photosynthesis for energy, but rather they filter food out of the water. Additionally sponges can reproduce sexually, as well as asexually. I hope this clears the issue up for you guys.
No, It is an organism
Its an animal.
animal
Sponges are animals of the phylum Porifera
plants and sponges
Coral, Seaweed and Sponges
they thought they were plants
Because they didn't move about about as most animals do. =)
Sponges look like plants. They do not appear to move and they are firmly attached to their substrate as if by roots. Unless you follow a sponge's life cycle, and see that the young sponges are motile, swimming freely in the water, and observe that sponges are not photosynthetic, obtaining their food by filtering microscopic organisms from the water, you might be confused.
Until about 200 years ago people thought that sponges were aquatic plants.
Because we wanted to call them sponges. Sponges belong to the animal kingdom since they are heterotrophic. Fungi derive food from breaking doown orgainc material in soil. Sponges feed on existing material. This is the difference.
soil is better
Sponges are not plants but animals .
plants and may be sponges
Animals. The part that we think of as "sponge" is their skeleton.