''Clathrina ceylonensis'' 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
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 ...
from Sri Lanka. The species name is derived from Ceylon, the former name of Sri Lanka.
Description
Cormus massive, formed of thin, irregular and tightly anastomosed tubes, with a reticulated surface. According to the original description, water-collecting tubes were present. The skeleton has no special organisation, comprising equiangular and equiradiate triactines. Actines are conical, with blunt tips, never rounded. Dendy described this species as a variety of ''
Clathrina coriacea
''Clathrina coriacea'' is a species of calcareous sponge belonging to the class Calcarea and family Clathrinidae. Species in the genus Clathrina are composed of calcium carbonate tube-like skeletons containing spicules. The sponge can be locate ...
''. He noted the presence of water-collecting tubes as ‘small but prominent true oscula formed each
by the coalescence of several tubes in a projection from the general surface’. He also found triactines measuring about 88 mm/8 mm, and ‘few very slender oxea’, which were probably trichoxeas. Klautau and Valentine studied the holotype. No trichoxeas were found, but these spicules are sometimes difficult to find. Klautau and Valentine therefore decided not to consider the presence of trichoxeas in their description. Klautau and Valentine elevated this variety to the status of a species because ''C. ceylonensis'' is very distinct from ''C. coriacea''. Despite morphological similarities, such as the presence of water-collecting tubes and the size of the triactines, they can easily be distinguished. ''C. coriacea'' has undulated actines with a constriction near the tip, which is rounded or blunt, while ''C. ceylonensis'' has straight actines with blunt, unrounded tips. The distribution of ''C. coriacea'' seems to be restricted to northern Europe, while ''C. ceylonensis'' occurs only in the Indian Ocean.
References
External links
World Register of Marine Species entry
Clathrina
Invertebrates of Sri Lanka
Sponges described in 1905
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