Corals & Sponges
Corals and sponges are known from the phenomenal films of the fantastic South Pacific. In Africa, holidaymakers can also observe these in all their diversity and in their natural environment. Here, sponges are not just known as b…
Sponges - Oldest Multicellular Organisms in the World
Sponges, also known as Porifera, are likely the oldest multicellular organisms on Earth. They were previously classified as plants. Sponges have a unique structure. The so-called sponge body has a central cavity, which in turn has various openings or mouths. Its outer layer is traversed by channels and cavities. These cavities are called flagellated chambers, which consist of collar cells. The collar cells create a water current by their movement. This water current contains tiny nutrients that sponges absorb through the fine pores on their surface. The filtered water is expelled through the top of the sponge. The sponge body consists of a skeleton, also known as spicules. These needles have a consistency of either calcium or silicic acid.
Tropical Kidney Sponge
The Tropical Kidney Sponge, also known as Chondrosida, loves the shallow waters of the African coast. Here, it lives in reef areas. It is named for its kidney-like shape, which also makes it unrecognizable. It consists of several layers of collagenous and soft tissue. It has a smooth, almost rubbery surface. Its body is almost shiny. The kidney sponge feeds almost exclusively by filtering. Therefore, it is only found in areas with low currents.
Corals
Corals are a fantastic species in their own right. They can live or survive at depths of up to 6,000 meters. Corals thrive in all the world's oceans. They love to form colonies and can spread very quickly under favorable conditions. A beautiful coral reef always has an intact ecosystem.
A very beautiful species of coral off the coasts of Africa is the stony coral. The stony coral, also known as Scleractinia, lives in the reefs of East Africa. This stony coral loves tropical coasts. Here, it has an optimal, bright, and nutrient-rich shallow water zone. Its relatives are found in the seas all over the world. The stony coral always remains in the same place. Here, they are stationary and immobile. Stony corals form a colony with many individual polyps. The optimal water temperature for stony coral is between 22-28 degrees Celsius.
The stony coral feeds on tiny planktonic organisms. However, it also has the ability to absorb and digest individual organic substances through its skin. A very important food source is a small alga, with which the stony coral lives in a close symbiosis.
