''Ascandra izuensis'' is a
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 ...
of
sea 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 ...
in the family
Clathrinidae
Clathrinidae is a family of calcareous sponges in the order Clathrinida. It contains the following genera:
''Arturia'' '' Borojevia'' '' Brattegardia'' ''Clathrina'' ''Ernstia
''Ernstia'' is a genus of calcareous sponges in the family Clathr ...
. The species is named after the
Izu peninsula
The is a large mountainous peninsula with a deeply indented coastline to the west of Tokyo on the Pacific coast of the island of Honshu, Japan. Formerly known as Izu Province, Izu peninsula is now a part of Shizuoka Prefecture. The peninsul ...
where the holotype was collected.
Description
''Ascandra izuensis'' is a
calcareous sponge
The calcareous sponges of class Calcarea are members of the animal phylum Porifera, the cellular sponges. They are characterized by spicules made of calcium carbonate in the form of calcite or aragonite. While the spicules in most species hav ...
. It is found in the Central Kuroshio Current,
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
.
The sponge consists of loosely branched and anastomosing ascon-tubes directly attached to a substratum. There is no pseudoderm covering the whole colony and no endogastric network. The sponge is rather small and attains a length of about 6 mm. The diameter of the ascon-tubes varies from 0.3 mm to 1 mm and the dermal surface of the tubes have a hispid appearance on account of projecting oxea. The colour of the sponge is yellowish-white when preserved in alcohol.
The skeleton of the sponge is composed of triradiates, large and small quadriradiates, and oxea. The tri- and quadriradiates are arranged in a few layers in the sponge wall. The quadriradiates are more numerous than the triradiates and their apical rays project into the gastral cavity. The larger quadriradiates are usually arranged in the dermal skeleton. The oxea occur vertically or obliquely to the surface of the ascon-tubes.
References
Clathrina
Animals described in 1942
Invertebrates of Japan
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