''Eusmilia'' is a genus of
stony coral in the
family Meandrinidae
The Meandrinidae are a family of stony corals. The name comes from the Greek, ''maiandros'' meaning "meandering", referring to the miniature, winding valleys found between the corallites. Fossil corals in this family have been found dating back ...
. It is a
monotypic genus represented by the
species ''Eusmilia fastigiata'', commonly known as the smooth flower coral. It is found on reefs in the
Caribbean Sea.
Description
Smooth flower coral is a
colonial
Colonial or The Colonial may refer to:
* Colonial, of, relating to, or characteristic of a colony or colony (biology)
Architecture
* American colonial architecture
* French Colonial
* Spanish Colonial architecture
Automobiles
* Colonial (1920 a ...
species that grows to about across. It forms a low mound of stony
calcium carbonate, the surface of which is covered with tubular projections, the
corallite
A corallite is the skeletal cup, formed by an individual stony coral polyp, in which the polyp sits and into which it can retract. The cup is composed of aragonite, a crystalline form of calcium carbonate, and is secreted by the polyp. Corallit ...
s, in groups of one to three. The
polyps protrude from these and are either round or oval, with the oval form being more common at moderate depths. They are large and widely spaced and are connected by a layer of translucent, jelly-like
mesoglea tissue called
coenosarc which covers the surface of the carbonate skeleton. During the day they are retracted back into the cup-shaped corallites. These have large smooth-edged ridges called
septa, and the polyps have corresponding grooves at their base. At night, the polyps stretch out their translucent white tentacles to feed and the coral "flowers".
Distribution and habitat
Smooth flower coral is found in the Caribbean, the Gulf of Mexico, the Bahamas and southern Florida, at depths down to about though it is commonest between . It is found on both the back and the front edges of reefs and is sometimes overhung by larger corals.
Biology
The polyps remain retracted in the skeleton during the day but extend at night to feed. The tentacles search for zooplankton and small invertebrates which are transferred to the mouth. Another major source of energy is the result of the symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
dinoflagellate
The dinoflagellates (Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. Dinoflagellates are ...
s which live within the coenenchyme and which produce nutrients by photosynthesis. The coral benefits from the carbohydrates produced and the algae use the coral's nitrogenous waste products.
Reproduction
Reproduction in corals takes place when gametes are released into the water. The fertilized egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
develops into a planula larva which forms part of the zooplankton and drifts with the current. After passing through a number of larval stages this settles on the sea bed and undergoes 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 ...
into a polyp. The base of this secretes the calcium carbonate skeleton and the polyp founds a new colony, producing new polyps by budding.[
]
References
{{Taxonbar, from1=Q13630238, from2=Q2785489
Scleractinia genera
Monotypic cnidarian genera
Meandrinidae
