What is the body symmetry of sponges
They concluded that this species could not produce isopropylcholesterol but that investigation of a wider range of choanoflagellates would be necessary in order to prove that the fossil isopropylcholestane could only have been produced by demosponges. The Caribbean chicken-liver sponge Chondrilla nucula secretes toxins that kill coral polyps , allowing the sponges to grow over the coral skeletons. Where do sponges come from?
Where do sponges come from? Sea sponges are animals that live on the ocean floor.
After human beings harvest and dry them, the sponges serve as the household tool many people use to b You May Also Like Q: What kind of fish do dolphins eat? What type of oil is PurCellin? What type of macromolecule is DNA?
What type of symmetry do sponges have?
The water brings in nutrients and oxygen and takes out the carbon dioxide. The two purposes of providing food and removing wastes are served due to this function. The sticky collars also pick up tiny particles of food and bacteria brought in by the water 2. Unlike the cells of most other animals, the cells of sponges do not form into various organs like kidney, liver, or nerves.
Sponge cells are totipotent Dawkins The totipotent cells could give rise to reproductive cells or other types of cells of the organism. In theory, this enables a sponge to live forever Dawkins Sponges can produce sexually as well as asexually. Most sponges are hermaphroditic, which means each adult can act as either female or male.
Asexual reproduction happens by budding and fragmentation 4. With this type of reproduction pieces or fragments of the sponge's body are broken off the by the water currents, and they are carried by the currents to a different location.
There they attach themselves to the ocean floor and grow to be an adult sponge. Some of the sponges form internal buds, called gemmules. These can survive even extremely unfavorable conditions. They survive even after the rest of the sponge dies due to the unfavorable conditions 4.
Sexual reproduction happens internally. The male acting sponge cells release the gametes into the water.
The tiny larvae which are the result of fertilization are released into the water. The larvae use their cilia to propel themselves through the water.
Eventually they settles down and grow to be an adult sponge. Next time around when they reproduce the sponges may change roles; the sponge that played male could play female and vice versa 4.
The Difference Between Bilateral & Radially Symmetric Animals
The evolution of multi cellular sponges from single-celled protozoa is one of the landmark events in evolution. Sponges occur in rivers and streams, from rock pools to the deep ocean depths, from frozen arctic seas to the warm tropical seas.
They are perhaps at their most beautiful in tropical marine seas. There are about 10, known species and though their basic organisation is pretty simple and remains fairly constant throughout the all species they do manage to show a great variety of forms. The body of a sponge is a collection of a few different types of cells loosely arranged in a gelatinous matrix called a 'mesohyl', mesoglea or mesenchyme.
This mesohyl is the connective tissue of a sponge body and it is supported by the skeletal elements. The skeletal elements of sponges are variable and important in taxonomy.
Throughout this body run canals through which water flows, there is considerable variation in the complexity of these canals. The canals have openings to the outside which are called pores, where the water enters the sponge system these pores are usually small and are called 'ostia' and where the water leaves the sponge system the pores are larger, often singular and are called 'oscula' singular osculum.
Many if not most of these canals are lined with special flagellated cells called 'choanocytes'. These choanocytes keep the water flowing through the canals in the correct direction by beating their flagellum, they are also important in trapping food items. There are three main types of canal system in sponges.
The simplest form is Asconoid, here the canals run straight through the sponge body and all the choanocytes line the central large space called the 'spongocoel'. The water enters the ostia, is drawn through to the spongocoel and leaves through a single large osculum. Asconoid sponges have cylindrical hollow bodies and tend to grow in groups attached to some object or other in relatively shallow seas.
Slightly more complicated are Syconoid sponges, externally they are fairly similar to asconoid sponges except that their body wall is thicker. The canals are branched however and do not allow the water to flow straight through in to the spongocoel. Instead the water flows a twisted route through a number of canals some of which are lined with choanocytes before being expelled into the spongocoel and out through the osculum. Almost all animals have some form of symmetry -- either bilateral or radial.
Sponges, meanwhile, are a major exception. An animal with radial symmetry could be divided into equal portions from the center, in the same way that you could cut a pie into wedges. An animal with radial symmetry really has no right and left side or head and rear end. Radial symmetry is ideal for animals that do not move, so they can reach into their environment on all sides.PORIFERA GENERAL CHARACTERS
Consider the starfish as an example of radial symmetry. Animals with bilateral symmetry can be divided only into mirror halves through a single plane. Higher animals that move are normally bilateral, with matching left and right sides.