Yes, Spongilla is a fresh water sponge.
Euplectella (Venus flower basket) , Sycon (scypha) and Hyalonema (Bath sponge) are marine forms of sponges belonging to phylum porifera.

Freshwater sponges are a type of sponge that inhabit freshwater environments such as lakes, ponds, and rivers. They are filter-feeding animals that play a crucial role in the ecosystem by filtering water and removing organic particles.

The correct answer to the question is option 'A', Spongilla. Spongilla is a genus of freshwater sponges that belongs to the family Spongillidae. They are commonly found in freshwater habitats and have a unique body structure and morphology.

Here are some key characteristics and features of Spongilla:

1. Habitat:
- Spongilla species are primarily found in freshwater environments such as lakes, ponds, and rivers.
- They attach themselves to various substrates such as rocks, logs, and plants.

2. Morphology:
- Spongilla has a soft, sponge-like body structure.
- They have numerous tiny pores, called ostia, through which water enters their bodies.
- The water is then filtered by specialized cells called choanocytes, which have flagella that create water currents.
- Choanocytes also trap and ingest food particles suspended in the water.

3. Reproduction:
- Spongilla reproduces sexually and asexually.
- Asexual reproduction occurs through the formation of gemmules, which are resistant capsules containing a group of cells capable of developing into new sponges.
- Sexual reproduction involves the release of sperm and eggs into the water, where fertilization takes place.

4. Ecological Importance:
- Freshwater sponges like Spongilla play a vital role in the ecosystem by filtering water and removing organic matter.
- They help maintain water quality by reducing the concentration of nutrients and pollutants.
- Spongilla also provides habitat and shelter for various microorganisms and small invertebrates.

In conclusion, Spongilla is a genus of freshwater sponges that are commonly found in freshwater habitats. They have a unique body structure, filter water to obtain food, and play an important ecological role in maintaining water quality.