Spongilla
Encyclopedia
Spongilla is a genus
of freshwater sponge in the family Spongillidae
. They are found in lakes and slow streams. Sponges of the genus Spongilla attach themselves to rocks and logs and filter the water for various small aquatic organisms such as protozoa
, bacteria
, and other free-floating pond life. Unlike marine sponges, fresh-water sponges are exposed to far more adverse and variable environmental conditions, and therefore they have developed gemmule
s as a means of dormancy. When exposed to excessively cold or otherwise harsh situations, the sponges form these gemmules, which are highly resistant "buds" that can live dormantly after the mother sponge has died. When conditions improve, the gemmules will "germinate" and a new sponge is born.
Spongilla was used by John Hogg (biologist)
in the nineteenth century to attempt to justify a fourth kingdom of Life
.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of freshwater sponge in the family Spongillidae
Spongillidae
The Spongillidae are a family of sponges that live in fresh water lakes. There are 23 genera....
. They are found in lakes and slow streams. Sponges of the genus Spongilla attach themselves to rocks and logs and filter the water for various small aquatic organisms such as protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
, bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, and other free-floating pond life. Unlike marine sponges, fresh-water sponges are exposed to far more adverse and variable environmental conditions, and therefore they have developed gemmule
Gemmule
Gemmules are internal buds found in sponges that are the result of asexual reproduction, and are a response to a hostile environment.They are resistant to desiccation , freezing, and anoxia and can lie around for long periods of time. These are similar to a bacterium's endospore...
s as a means of dormancy. When exposed to excessively cold or otherwise harsh situations, the sponges form these gemmules, which are highly resistant "buds" that can live dormantly after the mother sponge has died. When conditions improve, the gemmules will "germinate" and a new sponge is born.
Spongilla was used by John Hogg (biologist)
John Hogg (biologist)
John Hogg was a British naturalist who wrote about amphibians, birds, plants, and protist. In 1839 he became a member of the Royal Society....
in the nineteenth century to attempt to justify a fourth kingdom of Life
Life
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...
.