Top: Science: Animals: Porifera

Pages

[ history ]

Overview

Porifera, more commonly known as sponges, comes from the Latin words porus meaning "pore", and ferre which means "to bear." They are simple animals, lacking the internal systems of other multicellular organisms. Sponges feed by pumping water into and through their perforated outer surface into the interior, called the spongocoel. This process essentially allows them to "catch" particles of food matter floating in the water, while excess water is then expelled.

There are over 5,000 known species of sponge, with more being discovered regularly. They are ocean-dwelling, and can be found from the intertidal zone to as far out as 8,500 meters, or 29,000 feet and beyond.

Fossils of sponges date back to the Precambrian era, and the organism has changed little over time. It's body is tube-shaped, which one end being attached to a rock or other hard surface. The open end is called the osculum. The first fossils of sponges are from China and are about 600,000,000 years old. This has led many to believe that sponges may have been the first life on Earth.

Sponges have several uses in the modern world. The exterior and structure of a sponge, in which the living parts have been removed through maceration can be used in many tasks, such as cleaning or bathing. However, the popular loofa sponge is derived from plant material. The more recent development of synthetic materials has caused a slowdown in the commercial production of sponges, although there may still be surprises yet undiscovered. The Venus Flower Basket species has been newly discovered to have uses in fiber optics.


[ history ]

Reproduction

Sponges can reproduce sexually or asexually. Sexual reproduction occurs when a sponge releases sperm into the water. Eventually, some of the sperm may enter a sponge with eggs, causing internal fertilization. A sponge can reproduce asexually by a process called budding, when a small piece of the sponge breaks off and grows into a new sponge.

If the sponge is in a hostile environment, it can break itself down into several gemmules, or young sponges. These smaller sponges are more protected and can survive conditions that would be fatal to an adult sponge.



 All text is available under the terms of the GNU Free Documentation License. (See Copyright Policy for details.) 
© Open-Site Foundation, Inc.
Hosted by Android Technologies, Inc. the medical robotics news source.
Visit our sister sites dmoz.org | mozilla.org | chefmoz.org | musicmoz.org