Porifera

Porifera (Latin: = pore porous, fer = carry) or porous sponge or animal is a multicellular animal phyla for the simplest.

Morphologic characteristics include:

- porous body (ostium)
- multicellular
- Porifera body asymmetry (not uniform), although there is a radial symmetry.
- shaped like a tube, vases, bowls, or plant
- the color varies
- do not migrate (sessile)

Anatomic characteristics include:

- has three types of water channels, namely askonoid, sikonoid, and leukonoid
- intracellularly in the digestive tract and amoebosit koanosit

Porifera living heterotrophs. The food is bacteria and plankton. Foods that enter the body in liquid form so that Porifera is also known as liquid-eaters. Habitat is generally at sea sponges.

Sponges are animals of the phylum Porifera (/ pɒrɪfərə /, which means "pore bearer"). Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can turn into specialized cells, sponges are unique in having some specialized cells that can turn into other types, often migrating between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory system. Instead, most rely on maintaining a constant flow of water through their bodies to get food and oxygen and to eliminate waste, and their bodies are adapted to maximize the efficiency of water flow. All sessile animals and water, although there are freshwater species, most of which are marine (salt water) species, ranging from tidal zones to depths of more than 8800 meters (5.5 mi).

While most of the approximately 5.000 to 10.000 known species feed on bacteria and other food particles in the water, some host photosynthesizing micro-organisms as endosymbionts and these alliances often produce more food and oxygen than they consume. Several types of sponge that live in environment poor foods has been become carnivores which prey on primarily on small crustaceans. Most species use sexual reproduction, releasing sperm cells into the water to fertilize an ovum that is released in a few species and other people detained by the "mother". The fertilized eggs form larvae that swim off to find a place to settle. Sponges are known for regenerating from fragments that are broken, although this only works if the pieces including the correct type of cells. A a few species breed with shoots. As the condition worsens, such as temperatures drop, many freshwater and marine species that produces some of the gemmules, "survival pods" unspecialized cells that remain dormant until conditions improve and then form an entirely new framework or sponge recolonize their parents.

The mesohyl functions as an endoskeleton in most sponges, and is the only skeleton in soft sponges that encrust hard surfaces like stone. More generally, the mesohyl rigid by mineral spicules, by spongin fibers or both. Demosponges using spongin, and in many species, silica spicules and in some species, calcium carbonate exoskeletons. Demosponges is about 90% of all known species of sponges, including all fresh water, and has the widest range of habitats. Calcareous sponges, which have spicules of calcium carbonate and, in some species, calcium carbonate exoskeletons, are limited to relatively shallow marine waters where production of calcium carbonate is easiest. The fragile glass sponges, with a "scaffold" of silica spicules, limited to the polar regions and deep water where the prey is scarce. Fossils of all kinds have been found in rocks dated from 580 million years ago.

Besides Archaeocyathids, which are common fossils in rocks from the 530-490000000 years ago, is now considered a type of sponge. The sponge's closest relative is expected to be single-celled Choanoflagellatea, which closely resembles a sponge cells use to drive water flow systems and capture most of their food. Sponges are generally agreed, also, to not form a monophyletic group, in other words do not include all and only descendants of a common ancestor, because Eumetazoa (more complex animals) is considered to be descendants of a subgroup of the sponge. But certainly the closest to Eumetazoa sponges, both calcareous sponges and a sub-group of demosponges called Homoscleromorpha has been nominated by different researchers. In addition, a study in 2008 suggested the earliest animals may have been similar to modern comb jellies. Several species of demosponge that have entirely soft fibrous skeleton without hard elements have been used by humans for thousands of years for several purposes, including as padding and as cleaning tools. In the 1950s, though, it has been so heavily overfished that the industry almost collapsed, and most of the sponge-like material is now synthetic. Sponges and their microscopic endosymbionts are now being investigated possible sources of drugs to treat various diseases. The dolphins have been observed using sponges as tools while foraging.