Authors Authors and affiliations R. Manconi R. Keywords Taxonomic richness Geographic distribution Endemicity Habitat. This is a preview of subscription content, log in to check access. Annandale, N. Freshwater sponges, hydroids and polyzoa.
In Shipley, A. Google Scholar. Arndt, W. Die Spongillidenfauna Europas. Brien, P. Les Potamolepides africaines. Archives de Zoologie Experimentale et Generale — Efremova, S. New genus and new sponge species of the family Lubomirskiidae Rezvoy, Index of animal species inhabiting Lake Baikal and its catchment area. Ereskovskii, A. Comparative embriology of sponges and its application for poriferan phylogeny.
In Pansini, M. Pronzato, G. Frost, T. Clearance rate determinations for the freshwater sponge Spongilla lacustris : effect of temperature, particle type and concentration, and sponge size. In Thorp, J. Academic Press Inc. Harrison, F. Sponges Porifera: Spongillidae. In Hart C. Fuller eds , Pollution Ecology of Freshwater Invertebrates. Academic Press, New York, 29— Adult sponges are generally assumed to be completely sessile, but a few studies have shown that adult sponges in a variety of species can crawl slowly Bond and Harris Sponges have three different types of body plans, although these morphologies do not define taxonomic groups.
Asconoid sponges are shaped like a simple tube perforated by pores. The open internal part of the tube is called the spongocoel; it contains the collar cells. There is a single opening to the outside, the osculum. Syconoid sponges tend to be larger than asconoids and have a tubular body with a single osculum. The synconoid body wall is thicker and the pores that penetrate it are longer, forming a system of simple canals. These canals are lined by collar cells, the flagellae of which move water from the outside, into the spongocoel and out the osculum.
The third category of body organization is leuconoid. These are the largest and most complex sponges. These sponges are made up of masses of tissue penetrated by numerous canals. Canals lead to numerous small chambers lined with flagellated cells.
Water moves through the canals, into these chambers, and out via a central canal and osculum. Sponges in the class Calcarea , considered to be the most primative group, and have asconoid, synconoid and leuconoid members.
The Hexactinellida and Demospongiae groups have only leuconoid forms. Sponges are found in virtually all aquatic habitats, although they are most common and diverse in the marine environment. Many species contain toxic substances, probably to discourage predators. Ostia are surrounded by donut shaped cells called porocytes. The chambers within the canals are lined up with cells called choanocytes, or collar cells. The collar cells consist a sticky funnel shaped collar and a hair-like whip called a flagellum.
The collar cells beat their flagella back and forth to force the water through the sponge. 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. Demosponges from Ascension Island with a description of nine new species.
Chagas, C. Zootaxa, 1 : 39— Fernandez, J. New species of Crella Pytheas Topsent, and Crellomima Rezvoi, Crellidae, Poecilosclerida, Demospongiae from Chilean shallow and Argentinean deep waters, with a synthesis on the known phylogenetic relationships of crellid sponges.
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