''Lithophaga simplex'' is a species of
bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
in the
family Mytilidae. It is a boring species, tunnelling into living coral colonies. It can be found in the tropical western central Pacific Ocean.
Description
''Lithophaga simplex'' is one of the smaller members of its genus. The shell grows to a maximum length of and a width of . It is narrow and cylindrical, tapering slightly at the posterior end, with the
umbo near the anterior end. Both ends are rounded and the hinge line is straight. The
periostracum
The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods and ...
is yellowish and covered by a chalky crust. This mollusc can be distinguished from other similar species by its inflated shell and by the dark siphon.
[
]
Ecology
''Lithophaga simplex'' bores into living colonies of coral. In the Red Sea it is commonly found in the massive coral ''Astreopora myriophthalma
''Astreopora myriophthalma'', sometimes known as porous star coral, is a species of hard coral found in shallow water in the tropical Indian and Pacific Oceans. It is a common species with a wide range and the International Union for Conservation ...
''. The mollusc was at one time considered to be a parasite of the coral because its tunnelling activities weakened the coral structure and made it more liable to suffer damage. However it has now been found that the ammonium
The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...
products that the mollusc excretes serve as nutrients, and the benefits of these to the coral colony may outweigh the disadvantages of structural weakening, so the relationship between the two is probably mutualistic.host
A host is a person responsible for guests at an event or for providing hospitality during it.
Host may also refer to:
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* Host, Pennsylvania, a village in Berks County
People
*Jim Host (born 1937), American businessman
* Michel Host ...
corals for this bivalve include '' Goniastrea pectinata'',new moon
In astronomy, the new moon is the first lunar phase, when the Moon and Sun have the same ecliptic longitude. At this phase, the lunar disk is not visible to the naked eye, except when it is silhouetted against the Sun during a solar eclipse.
...
. The larvae followed the normal course of development of mytilids. When the veliger larvae were well-enough developed to settle on the seabed, they were capable of delaying metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
by up to four months, a fact that would enable them to disperse widely while searching for suitable substrates on which to settle.[
]
References
{{Taxonbar, from=Q13768396
simplex
In geometry, a simplex (plural: simplexes or simplices) is a generalization of the notion of a triangle or tetrahedron to arbitrary dimensions. The simplex is so-named because it represents the simplest possible polytope in any given dimension. ...
Molluscs described in 1939
Molluscs of the Pacific Ocean