Homoscleromorpha
Encyclopedia
Homoscleromorpha is a subclass (possibly a class) of marine demosponge
s containing a single order, Homosclerophorida and a single family, Plakinidae.
There are less than 100 species in this family divided into 7 genera.
The spiculate genera in this family are Corticium
, Plakina, Plakortis and Plakinastrella.
The aspiculate species are the genera Oscarella and Pseudocorticium.
form (all spicules tend to be very small). Reproduction is viviparous and the larva
is an oval form known as an amphiblastula. This form is usual in calcareous sponge
s but is less common in demosponges.
Demosponge
The Demospongiae are the largest class in the phylum Porifera. Their "skeletons" are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges...
s containing a single order, Homosclerophorida and a single family, Plakinidae.
Taxonomy
This class has recently been recognised as the fourth major line of sponges.There are less than 100 species in this family divided into 7 genera.
The spiculate genera in this family are Corticium
Corticium
Corticium is a genus of crust fungi in the family Corticiaceae. According to a 2008 estimate, the genus contains 25 widely distributed species.-Species:*Corticium appalachiense*Corticium auberianum*Corticium boreoroseum...
, Plakina, Plakortis and Plakinastrella.
The aspiculate species are the genera Oscarella and Pseudocorticium.
Description
These sponges are massive or encrusting in form and have a very simple structure with very little variation in spiculeSpicule
Spicules are tiny spike-like structures of diverse origin and function found in many organisms, such as the copulatory spicules of certain nematodes or the grains on the skin of some frogs.In sponges, spicules perform a structural function....
form (all spicules tend to be very small). Reproduction is viviparous and the larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
is an oval form known as an amphiblastula. This form is usual in calcareous sponge
Calcareous sponge
The calcareous sponges of class Calcarea are members of the animal phylum Porifera, the cellular sponges. They are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite...
s but is less common in demosponges.