![]() They are capable of reacting quickly owing to the electric impulse they generate. ![]() The glass sponges are very sensitive to external stimuli. Glass sponges can live for 15,000 years which places them amongst longest living creatures on earth (Posidonia oceanica, a seagrass is the longest living organism with a lifespan of about 200,000 years). Their body is cup-shaped the spicules present on their body are made up of siliceous compounds. Generally, they are found at great depths (450-900m) in oceans. 2008) Sponges strain out bacteria, viruses, and other microscopic particles, leaving the water exiting the top of the sponge tube (the osculum) virtually sterile. These sponges are of rare occurrence in nature. The azure vase sponge, Callyspongia plicifera, pumps 6.5 liters of water per second per kilogram of dry sponge weight (Weisz et al. The different types of glass sponges make up the class Hexactinellida. Gordon Love, a scientist from California University, demosponges came into existence as early as 635 million years ago i.e. Gemmules are internal buds present in sponges that are capable of developing in favorable conditions they remain dormant in the absence of favorable conditions. Asexual reproduction takes place by means of gemmules and budding. These organisms exhibit great variety of form and are much more diversified than other classes of sponges. Some of the demosponges reproduce sexually while the others asexually. Demosponges live in warm as well as cold areas of oceans. They are largest of all sponges and form 90% of their total number. The demosponges, just like calcareous sponges are made up of spicules however, in demosponges, spicules are formed of fibers produced from a protein called ‘spongin’. They are just 10cm in length however, they encompass different kinds of structures like: ![]() Spicules are made up of calcium carbonate and form a skeleton of calcareous sponges. Such type of structures, in case of calcareous sponges, are known as spicules. Classification of sponges is carried out on the basis of their reinforcing structures.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |