Shoulderblade Coral

Pavona clavus

It is a zooxanthellate reef coral of the family Agariciidae.
Shoulderblade Coral - Pavona clavus I wanted to introduce this beautiful coral species with a picture of my husband Mark filming small critters living in this massive colony. I have seen an article mentioning this very same coral boulder and the writer - Nicole Helgason- estimates its age in 600 to 800 years old! This is in the dive site Kelapa 21 of Weda, Halmahera. In the dive site Gorangos there are even bigger colonies. The beauty of this one is its almost perfectly sphaerical shape when photographed from above with a wide angle lens. And I am happy to say that this coral is for the moment not in the least of threatened species (which does not mean we should not worry about its future well-being). It hope it will still be there long after we are all gone. By the way, this is the article: 
https://reefdivers.io/protecting-elders-pavona-clavus/7979 Fall,Geotagged,Indonesia,Pavona clavus,Shoulderblade Coral

Appearance

The species has distinctive colonies which are basically massive, but with numerous club shaped or cylindrical, stout columns. These columns divide, and are usually oval in cross-section, and then remain separate from adjacent columns. The typical, star shaped Pavona corallites are clearly visible in live corals, and like most Pavona, the corallite walls are thick, so the calices are well separated. The smooth edged septa cross the broad walls. The colonies commonly reach a metre high and a metre across. The living colour is usually brown or green (Sheppard, 1998).
Colonies are columnar or laminar, or both. Columns divide but do not anastomose. Corallites are thick-walled. Columellae are short or absent. Colour: uniform pale grey, cream or brown. Abundance: common on some shallow upper reef slopes exposed to currents, and may be dominant coral forming extensive monospecific stands (Veron, 1986).
Grows in plates or stout columns, or a combination of both. Colour: varies from pale grey or green to yellowish-brown. Habitat: shallow reefs with strong currents (Richmond, 1997) [details]

Distribution

Indo-Pacific. Common in the central Indian Ocean, and listed for the northern Red Sea, but if present, they are extremely rare there.

Status

Least Concern.

Behavior

Known to develop into huge colonies, hundreds of years in age.

Habitat

Reef-associated; depth range 0 - 65 m.

Reproduction

Members of the class Anthozoa are either gonochoric or hermaphroditic. Mature gametes are shed into the coelenteron and spawned through the mouth. Life cycle: The zygote develops into a planktonic planula larva. Metamorphosis begins with early morphogenesis of tentacles, septa and pharynx before larval settlement on the aboral end.

References:

Some text fragments are auto parsed from Wikipedia.

http://www.coralsoftheworld.org/species_factsheets/species_factsheet_images/pavona-clavus/
http://www.marinespecies.org/aphia.php?p=taxdetails&id=207318
https://www.sealifebase.ca/summary/Pavona-clavus.html
Taxonomy
KingdomAnimalia
DivisionCnidaria
ClassAnthozoa
OrderScleractinia
FamilyAgariciidae
GenusPavona
SpeciesPavona clavus
Photographed in
Indonesia