''Spongilla'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of freshwater sponges containing over 200 different species. Spongilla was first publicly recognized in 1696 by Leonard Plukenet and can be found in lakes, ponds and slow streams.''Spongilla'' have a leuconoid body form with a skeleton composed of siliceous spicules. They are sessile organisms, attaching themselves to hard substrate like rocks, logs. and sometimes to ground. Using their ostia and osculum these sponges filter the water for various small aquatic organisms such as

protozoa Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...

ns,

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

, and other free-floating pond life. Sponges of the genus ''Spongilla'' partake in symbiotic relationships with the green algae, zoochlorellae, which gives the sponges a green appearance, and without which they would appear white. ''Spongilla'' was used by John Hogg in the 19th century to attempt to justify a fourth kingdom of

life Life, also known as biota, refers to matter that has biological processes, such as Cell signaling, signaling and self-sustaining processes. It is defined descriptively by the capacity for homeostasis, Structure#Biological, organisation, met ...

Reproduction

Sponges are

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

s, producing both

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the ...

and

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

. Sperm is released from one sponge and brought in through the ostia of another sponge. Once the sperm reaches the body cavity it fertilizes an egg, which develops into a free-swimming

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e. The free-swimming larvae are released out the osculum and will eventually settle and attach elsewhere. Since the larvae are developed inside the spongilla it is viviparous. Unlike marine sponges, freshwater sponges are exposed to far more variable environmental conditions, so they have developed gemmules as an overwintering mechanism. When exposed to excessively cold or other harsh conditions, the sponges form gemmules. Gemmules are highly resistant buds that can live dormant for extended periods of time. When conditions improve, the gemmules "germinate" and a new sponge is born.

Species

* '' Spongilla alba'' Carter, 1849 * '' Spongilla arctica'' Annandale, 1915 * '' Spongilla cenota'' Penney & Racek, 1968 * '' Spongilla chaohuensis'' Cheng, 1991 * '' Spongilla gutenbergiana'' Müller, Zahn & Maidhof, 1982 * '' Spongilla helvetica'' Annandale, 1909 * '' Spongilla jiujiangensis'' Cheng, 1991 * '' Spongilla lacustris''

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

, 1758 * '' Spongilla mucronata'' Topsent, 1932 * '' Spongilla permixta'' Weltner, 1895 * '' Spongilla prespensis'' Hadzische, 1953 * '' Spongilla sarasinorum'' Weltner, 1901 * '' Spongilla shikaribensis'' Sasaki, 1934 * '' Spongilla stankovici'' Arndt, 1938 * '' Spongilla wagneri'' Potts, 1889

References

;Footnotes ;Bibliography * Myers, P., R. Espinosa, C. S. Parr, T. Jones, G. S. Hammond, and T. A. Dewey. 2006. The Animal Diversity Web (online). Accessed February 19, 2007 at http://animaldiversity.org. * *

External links

*
Integrated Taxonomica Information System (ITIS): Spongilla Lamarck, 1816 Taxonomic Serial No.: 47692

National Center for Biotechnology Information (NCBI): Spongilla Taxonomy ID: 6054
{{Authority control Sponge genera Spongillidae Taxa named by Jean-Baptiste Lamarck