''Bolosoma'' is a genus of pedunculated siliceous sponges belonging to the family

Euplectellidae Euplectellidae is a family of glass sponges (Hexactinellids) belonging to the order Lyssacinosa Lyssacinosida is an order of glass sponges belonging to the subclass Hexasterophora. These sponges can be recognized by the parenchymal spicule ...

. This genus lives in deep-sea environments and provides a habitat for a plethora of other benthic species, giving ''Bolosoma'' an incredibly important ecological role in the ecosystems it is a part of. Bolosoma_Symbionts

General Ecology

Siliceous sponges such as ''Bolosoma'' are habitat building species, with many groups such as

echinoderm An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea ...

s and marine worms living on them. Even when dead, Bolosoma peduncles can provide structure for organisms like

ophiuroids Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomo ...

. Similar to many other taxa of deep-water suspension feeders, the diet and feeding habits of ''Bolosoma'' are relatively unknown due to lack of study. The reproductive dynamics of ''Bolosoma'' likewise are relatively unknown. Due to their habitat-building ecological role, deep-sea siliceous sponges such as ''Bolosoma'' have been used as indicator taxa of the stability of the ecosystems they inhabit, especially for vulnerable marine ecosystems on seamounts. By observing how healthy the populations of

Hexactinellid Hexactinellid sponges are sponges with a skeleton made of four- and/or six-pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consi ...

a sponges like ''Bolosoma'' are in commercially important environments such as the Emperor Seamount Chain, scientists can draw conclusions about how best to manage fishing practices in those areas.

Morphology

The body plans of this genus all consist of the main body suspended above the substrate by the peduncle. This main body can exhibit a variety of forms, such as fungiform or vase-like. This genus exhibits the leuconoid form, containing its choanocytes in a series of unlinked chambers. In terms of their visible-to-the-naked-eye megasclere spicules, all ''Bolosoma'' species have two-rayed diactin

spicules Spicules are any of various small needle-like anatomical structures occurring in organisms Spicule may also refer to: *Spicule (sponge), small skeletal elements of sea sponges *Spicule (nematode), reproductive structures found in male nematodes ( ...

forming one or more parts of their body structure. For all currently surveyed species, basalia spicules were found to be diactines, with the peduncle being shaped by long diactines. The choanosoma, atrialia, and dermalia spicules of most ''Bolosoma'' species consist mainly of diactines, with six-rayed hexactin and five-rayed pentactin spicules also present in lower concentrations. In species with hexactin dermalia the ray of each spicule directed outside of the sponge wall is wider than the other rays. In species with hexactin atrialia the spicule ray facing inward towards the center of the body is wider than the other rays. The microscopic microsclere spicules of this genus vary greatly by species. Some common microscleres found in Bolosoma species' skeletons are the ball shaped discohexasters and the many-armed branching codonhexasters, the latter of which may have anchor-like structures at the ends of its branches.

Habitat and Distribution

The Bolosoma are benthic organisms that live exclusively in the deep sea, preferring hard, rocky substrates such as old lava flows. This genus is found as deep as over 3,700 meters in some parts of the Pacific Ocean. In these environments, Bolosoma species can be the dominant benthic species, being incredibly common in areas such as seamounts. The substrate Bolosoma can grow on varies, with this genus being found on polymetallic nodules and softer surrounding sediments in areas such as the

Clarion-Clipperton Fracture Zone The Clipperton Fracture Zone, also known as the Clarion-Clipperton Zone, is a geological submarine fracture zone of the Pacific Ocean, with a length of around 4500 miles (7240 km). The zone spans approximately . It is one of the five major l ...

. Of the currently nine identified species in genus ''Bolosoma,'' all live exclusively in the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

with the exception of ''Bolosoma perezi'', which can be found in the Rio Grande Rise in the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

Potential Conservation Concerns

While the conservation status of ''Bolosoma'' has not been thoroughly studied, this genus and similar taxa are threatened by some notable human activities. Siliceous sponge genera such as ''Bolosoma'' are commonly found on polymetallic nodules, and future deep-sea mining of those areas represents a serious threat to those genera and species that live on them. In response to unusually high suspended sediment concentrations in the surrounding water, siliceous sponges will stop actively pumping water, causing them to be unable to access food or expel waste.

Trawling Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different speci ...

can cause highly increased suspended sediment concentrations, which causes nearby siliceous sponges to stop filtering and face adverse health effects.

References

{{Taxonbar, from=Q4125534 Hexactinellida Hexactinellida genera Animals described in 1904