The sponges are Acoelomates. That is they don't have coelom or body cavity.
No. they are coelomic
Yes, they are truly coelomic.
Brittle stars have a complex coelomic system, consisting of a spacious coelomic cavity that accommodates their internal organs. This coelomic system aids in internal transport, support, and protection of organs.
A modular or medullary sponge kidney is a congenital birth defect of the tiny tubes inside the kidneys. This condition is known as CacchiÐRicci disease.
Peritoneum
The coelomic cavity in a starfish functions primarily for circulation of nutrients, oxygen, and waste products throughout the body. It also houses the water vascular system, which helps in movement, feeding, and respiration by regulating water pressure in the tube feet.
Coelomic fluid acts as a hydrostatic skeleton in some invertebrates, providing support for the body wall and aiding in movement. It also plays a role in nutrient transport, waste removal, and gas exchange within the coelom.
nephridia
A person that eats sponge rollers may have the eating disorder called pica. This is a condition in which people eat substances that lack nutrition, such as paint, clay, soil, and stones.
In my opinion and the way I practice, earthworms are directly (known weight of earthworms) are added to a tray containing known volume of luke warm water(37 to40C) and agitated for about 30 to 60Sec. The heat shock makes them to throw out the coelomic fluid through dorsal pores and the mouth in to tray. T he earthworms are collected back and added in to other tray containing water at room temperature. This helps them to overcome shock and the fluid sticking to their body mixes with the water. Earthworms will be safe and can be left back in to their bins. Mix the water in two trays and this will be the vermiwash or it is coelomic fluid in diluted form. As one is washing the earthworms in water, it is called vermiwash. Coelomic fluid can be collected dirctly from the coelomic cavity by subjecting earthworms to cold shock or mild electric shocks. This is carried out to understand various components in coelomic fluid for scientific investigations. Vermiwash can be used as spray in nurseries.
Mollusks use a structure called the crystalline style to extract useful molecules from their coelomic fluid. The crystalline style is a rod-like structure located in the stomach that grinds up food particles and releases digestive enzymes to break down food for absorption. This process allows mollusks to efficiently extract nutrients from their coelomic fluid.
no, a land hermit crab is not supposed to eat the sponge unless they are in bad condition