''Monorhaphis'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of siliceous deep sea

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 ...

sponge Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through t ...

s. The single

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

''Monorhaphis chuni'', a sponge known for creating a single giant basal spicule (G.B.S.) to anchor the sponge in the sediments. The species was described by Franz Eilhard Schulze in 1904 from specimens collected by the German Deep Sea Expedition in 1898-1899. ''Monorhaphis'' is also the only genus in the monotypic family Monorhaphididae. One study provides substantial evidence that an individual of this deep-sea sponge, that forms giant spicules up to 3 meters long, is about 11,000 years old. Five other individuals collected from depths of 1,100 to 2,100 meters at three widely separated locations in the western Pacific Ocean were estimated to be 6,000 to 18,000 (±1,000) years old and grew radially at about 140 μm per 1,000 years. The samples were shown to record deep ocean silica geochemistry throughout their lives.

References

Hexactinellida Sponge families {{sponge-stub