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Family Agariciidae: (Gk. agarikon, mushroom).... possibly relating to the growth form , which can be flattened like a mushroom.
This is a Cenozoic Tethyan family, with most genera now extant. The family had a fate in the Atlantic similar to that of the Pocilloporidae, due to the extinction of Pavona and Gardineroseris, and reduction of Leptoseris to a single species. Agaricia is now the only speciose Caribbean genus.
Colonies are massive or laminar. The corallites are usually highly modified and immersed with poorly defined walls formed by thickening of the septo-costae. The corallites are usually highly modified and immersed with poorly defined walls formed by thickening of the septo-costae. In some species, the septa between adjacent corallites are continuos and do not fuse. These loosely packed costae with finely serrated margins spread from the center of one calice to the next (Veron 1986) give the colonz a distincitve linked pattern - for morphological characteristics see table.

The pattern formed by the costae, which resembles the patterns of feathers on a peacock's tail, may have given the species its name, since pavo derives from the Latin word for peacock (Wood 1983). In Pavona clavus the continuos septae-costae give the corallites a star-like appearance.
Agariciidae has six extant reef-building genera, with five genera found in the Indo-Pacific (i.e. Pavona, Leptoseris, Coeloseris, Gardineroseris, and Pachyseris). The name giving genus Agaricia is restricted to the Atlantic. All five Indo-Pacific genera are found in PNG. Of the five, Leptoseris has the widest geographic range, extending from the Indo-Pacific to the Caribbean.


Some members of the family Agariciidae (112kB)

Agariciidae are very common on most reefs and are often one of the early colonizers following environmental disturbances. In the Caribbean, Agarica is regarded as a weedy and opportunistic species. They are most abundant in shallow intertidal habitats, whereas Leptoseris is mainly restricted to deeper reef slopes. Pavona minuta and P.clavus can form massive aggregations extending for tens of meters along the reef. They are especially common on the upper reef slopes exposed to strong currents.
Agariciidae ccontain mainly gonochoric species. However, some species may be hermaphroditic or mixed. It seems that hermaphroditic or mixed species are from the Caribbean (e.g. Agaricia agaricites forma A.danai), while the Indo-Pacific species are gonochoric. The Caribbean agariciids have been extensively studied, while the reproductive biology of the Indo-Pacific genera (e.g. Pavona) are relatively unknown. It has been observed that P.cactus shed sperm, while other observations reported the presence of eggs in P.explanulata, and P.varians (Marshal and Stepehnson, 1993; Stimson, 1978). Both Pachyseris rugosa and P.speciosa are gonochoric, and were observed to spawn during mass-spawning events.

Family Agariciidae Colony not massive Corallite centers discernible Polyps aligned between collines Corallites without individual walls: Genus Agaricia
Corallites with individual walls: Genus Leptoseris
Polyps not aligned between collines: Genus Pavona
Corallite centers not discernible: Genus Pachyseris
Colony massive Corallites in concavities: Genus Gardineroseris
Corallites not in concavities: Genus Coeloseris
Indo-Pacific: -------------------------------------------------------------------------------------------------------------------

Pavona (L. pavo, peacock):

Pavona is readily divided into 'leafy' and 'non-leafy' groups of species that have ill-defined relationships. The latter are not clearly delineated from Leptoseris. Most species of Pavona are well-defined, widely distributed, and show relatively little geographic variation in morphology, colour or abundance.
Colonies are foliaceous (forming small to large leafy vertical plates), encrusting, or massive with a pale brown, with some showing shades of gray, pink, purple, green or yellow colors. Foliaceous species are bifacial (corallites on both sides). Immersed calices are round, polygonal, or oval and 2-3mm in diameter. Septa are visible with fine lines running from one calice center to the next (septo-costae). Septa are serrated and in cycles and not all reach the columella. Budding is intratentacular. P.explanulata with coenosteal grooves.
PRESENT DISTRIBUTION: Red Sea and western Indian Ocean to far eastern Pacific.
GENERAL ABUNDANCE: very common, conspicuous.
FOSSIL RECORD: Eocene (?) of the Caribbean, Oligocene of the Tethys and Pacific.
NUMBER OF EXTANT SPECIES: 15 known species.
Coeloseris (Gk. koilos, hollow; seris, lettuce): C.mayeri as the only member, forms colonies that are massive and rounded with pale brown, green or yellow colors. Monocentric corallites that are either rounded or polygonal with shared walls (a profile stretching over several cortallites displays a "sinusoidal" cross-sectional pattern). The top of the walls is rather flattened and has a reticulate appearance. Calices are 2-5mm in diameter with upt o 20-30 septa in a 3mm calice. Septa are arranged in cycles, slightly exsert and leafy. Columella is absent. Superficially is easily confused with some Goniastrea species.
PRESENT DISTRIBUTION: Central Indian Ocean to central Pacific.
GENERAL ABUNDANCE: Generally uncommon, sometimes cryptic.
FOSSIL RECORD: ?Miocene of the Pacific.
NUMBER OF EXTANT SPECIES: 1 known species.
Gardineroseris (named after S.Gardiner; Gk. seris, lettuce). G.planulata is one of the most widespread of Indo-Pacific species. Pliocene fossils are indistinguishable from, the extant and the same species is recorded in the Pliocene of the Caribbean.
This colony forms massive molds, columnar, encrusting, or partially folliaceous and is pale to dark-brown in color, sometimes purplish. Calices are polygonal, irregular, or elongate with a diameter of 2-5mm housing 1 to 5 callices (mono to polycentric). Calices are closely packed with shared corallite walls that are narrow and prominent (a profile stretching over several cortallites displays a U-shaped cross-sectional pattern). The walls are several mm high, with the septa dipping down deeply into the fossa. Septa are arranged in cycles with only the larger ones running from one calice to the next. Septa are usually slightly expanded at their inner ends and can be smooth or granulate in appearance.
PRESENT DISTRIBUTION: Red Sea and western Indian Ocean to far eastern Pacific.
GENERAL ABUNDANCE: generally uncommon, sometimes cryptic.
FOSSIL RECORD: Miocene of the Caribbean and Pacific.
NUMBER OF EXTANT SPECIES: 1 known species.
Pachyseris (Gk. pachys, thick; seris, lettuce): Forms leafy, plate-like (unifacial, corallites on the upper side only), encrusting, or massive colonies, that are pale to dark brown in color. Upper surfaces is closely packed with ridges and valleys which are arranged in neat concentric rows that run between corallites. Distances from mid-ridge to mid-ridge are usually 3mm. Because of the arrangement of the septa, calices are present (but indistinct) in the valleys. Septa are fine, numerous, and regular in appearance. They run across valleys in right angles to the ridges over which they pass uninterrupted. Occur in areas such as the edges of surge channels.
PRESENT DISTRIBUTION: Red Sea and western Indian Ocean to western Pacific.
GENERAL ABUNDANCE: very common, very conspicuous.
FOSSIL RECORD: Eocene (?) of the Pacific, Miocene of the Tethys.
NUMBER OF EXTANT SPECIES: 5 known species.
Circum-tropical distribution (only L.cailleti & L.cucullata are present in the Atlantic region)--------------------

Leptoseris (Gk. leptos, slender; Gk. seris, lettuce):

Members of this genus are mostly widespread like Pavona, but unlike Pavona, they show substantial geographic variation. They form encrusting colonies with sometimes extensive lateral dichotomal branched folia (thin and fragile) or ascending leafy scrolls and crests. They are brown, green, dark-red, or gray in color. Tips of the scrolls and crests are paler or white. Usually with a central corallite and others scattered around it. In some species gentle concentric ridges are developed. Calices are usually present only on the upper surfaces of the folia (unifacial). Calices are 2-5mm in diameter. Septo-costae are numerous, closely packed and unite adjacent corallites. Columella are weakly developed. Found in shaded parts of the reef, such as overhangs and caves.
PRESENT DISTRIBUTION: Red Sea and western Indian Ocean to far eastern Pacific and Caribbean and Gulf of Mexico.
GENERAL ABUNDANCE: sometimes common, mostly conspicuous.
FOSSIL RECORD: Oligocene of Caribbean, Tethys and Indian Ocean.
NUMBER OF EXTANT SPECIES: 16 known species.
Atlantic genus: ----------------------------------------------------------------------------------------------------------------

Agaricia (Gk. agarikon, muschroom):

Develops usually thin-walled foliaceous, encrusting, or semi-massive colonies. They consist of vertical crests or fronds with calices on one or both sides (bi- or unifacial fronds) with brown, green, pink, purple, or yellow colors. Tiny dot-like mouths are visible. Corallites are crowded with shared walls. Calices are round, polygonal, or oval and 2-5mm in diameter. Septa are visible but closely packed and radiate from the calice center in fine lines. Septa are in clycles with thick and thin ones alternating in some species. Septal margins are smooth or minuted dentated and merge with those of adjacent corallites and thus do not represent real septo-costae. Columella is weakly developed.
PRESENT DISTRIBUTION: western to eastern Atlantic.
GENERAL ABUNDANCE: generally common, very conspicuous.
FOSSIL RECORD: Miocene of the Caribbean and Tethys.
NUMBER OF EXTANT SPECIES: 7 known species.