Porifera Digestive System
Porifera are multicellular organisms that lack the individual body systems dedicated to a certain task that other organisms due. They function through a mechanism of sucking water in through pores on the bottom of the chimney like structures and control the water flow by dilating and contracting the upper exit, known as the osculum. The name Porifera comes from Latin, meaning "pore bearer" due to their porous consistency. The sponge does not have a traditional digestive system dedicated to a singular function and divided into sections. Rather, the cells lining the inner tube and the water flow mechanism replace the systems found in other organisms by meeting the needs of the sponge by collecting the needed resources from the flowing water.
Staurocalyptus Sp. (Glass Sponge)
All sponges are sedentary filter feeders lacking a true digestive system like those of other organisms. As filter feeders, sponges take in water through pores at the bottom and it travels out through a top opening know as the osculum. Sponges lack a dedicated independent digestive system. Instead, the inner walls of sponges are lined with cells known as choanocytes, that have long flagella used to catch and consume bacteria sized particles in the water. Other cells are also responsible for collecting necessary nutrients. Sponges are classified according to number of different characteristics yet all use the same system for gathering the necessary food and nutrients for their survival. In the case of glass sponges, their basic structure is made out of silicon dioxide. |
Clathrina clathrus (Calcareous sponge)
Calcareous sponges collect food in the same way as all other sponges. They are sedentary and cannot move. They suck water in at the bottom and release it through the osculum, gathering necessary food and nutrients using choanocytes. Sponges are often aided in this process by the suction fot the currents above. Calcareous sponges are known as such do tue the fact that their basic structure is formed out of Calcium Carbonate. |
Xestospongia testudinaria (Barrel Sponge)
Barrel sponges also use the flow of water to collect food, nutrients and oxygen in their inner linings. The greater the size of a sponge, the greater amount of food is need and therefore more water has to flow through the sponge. The larger opening allows for this greater water flow. The Barrel Sponge, unlike the two aforementioned sponges, has a skeleton constructed from a mix of silicon dioxide and the protein spongin. |