the poríferos (sea sponge) are invertebrates known as sponges. Its main feature is that the body is completely filled pores through which water circulates, therefore they called poríferos. Until 1.765 it was thought that sponges were plants, until it was discovered that had internal currents and intracellular digestion performed. Another fact that I had passed unnoticed until recently is that sponges if they can move, but they are moving so slowly (some 4 mm al día) that the fact had passed completely unnoticed.
there are a 9.000 different species of sponges worldwide, of which only a hundred and fifty species live in freshwater, the rest of the sponges live in the sea. His most important feature that gives this group of animals (poríferos), It is that their bodies are covered by a succession of pores and channels, through which water passes, and they serve you to get your food and oxygen needed to live.
Morfología. Features sea sponges
Morphologically perhaps the highlight of the sponges is that no body symmetry. But is that not need. Visually They are sac Y, although the shape can vary among different sponges, all they have a body structure related. Some species are able to adapt its shape to the middle, changing its appearance depending on the inclination of the substrate, or collide with a rock. the poríferos They are formed by two layers of cells, separated by an interior space. The outer layer of sea sponge is called pinacodermo, and it is formed by very similar to epithelial cells (of the skin), calls pinacocitos. The inner layer is called coanodermo, and it is formed by cells called choanocytes. These cells are provided with a flagellum and microvilli on the whole surface, to promote circulation of the water and turn, take advantage of their nutrients. They have a higher opening or atrial cavity called ósculo, responsible for circulation porifers. Through the atrial cavity sponge pumps water through the body, by passing through the walls full of pores of different sizes. They have no mouth, or digestive tract. You gets the nutrients it needs filtering water, by cells that have only sponges, choanocytes. Nor they have nerve cells. curiously, They are the only ones animals They lacking a nervous system. Although they are animals, Porifera have tissues, or differentiated organs. Instead they possess totipotent cells called, mutating to adapt at all times to cellular needs of the animal. Así, if the animal loses mass for any reason, it becomes regenerate. They have no natural predators. Its skeleton of spicules and toxicity, fends off other marine animals.
Types of sponges
Sponges are classified into four different classes: calcareous sponges They characterized by having calcareous spicules and lack spongin fibers. present Three different types of morphology: ascon, sicon y leucon, are small and usually pale. Demosponjas The 90% Sponges belong to this type of sponge, Y its main characteristic is that the skeleton comprises units skeletal silica, spongin fibers or a mixture of two options. Its coloration is very striking: reddish tones, green or blue. Its shape is varied, allowing to adapt very well to the middle, colonizing all surfaces and crevices. sponges vitreous (Hexactinellida) Son Porifera with siliceous skeleton formed by spicules six radios, known as hexactinas, which gives its name to the group. In addition to the siliceous spicules, may also have fibers espongina. Usually they have cup-shaped receiving preference shallow waters, between 200m and 2.000 mts. Archaeocyatha This is a group of sponges extinct.
Distribution and habitat
Porifera are animals with brutal power of adaptation, They are able to live in highly contaminated waters, under conditions where others could not survive. Nevertheless, what nature has not been able, if you are getting humans to climate change, which kills far sponges every year. even so, we can find sea sponge over all the oceans and seas of the world. highlights the seas, the amount of sponges that can be found are the Mediterranean on its eastern area, in the Gulf of Mexico, the Caribbean and the seas surrounding Japan. Sponges can live many levels deep, although they prefer those environments where light from the sun reaches weakly.
Diet: Â¿Cómo sponges feed?
sponges They get the food they need by filtering the water. Through the obtained filtration plankton, bacteria and small organic particles, which they are dissolved in the water of the sea. sponges They can establish relationships with other marine animals, as fish and other invertebrates, as well as bacteria and other unicellular organisms, that they provide access to organic matter which also serves food.
Sea sponges can be played in two different ways: sexual and asexual.
Sexual reproduction is perhaps the most complicated. Sponges lack sexual organs, as well as any other specialized body, so fertilization actually produced externally. Sea sponge are mostly hermaphrodite, although it differs from one species to another. For sexual reproduction, it needs a outcrossing. Both sperm and eggs develop from coanocitos, which they are driven by sponges and abroad, where binding occurs between cells. Once the egg is fertilized, sponges undergo different larval stages, until they become adult individuals.
I remember that I mentioned earlier called totipotent cells, adopting all kinds of funcionesâ € | Sea sponges produce yolks. They are lumps that grow until they emerge from the sponge unique, Y through its totipotent cells, these new individuals are completely autonomous.