Latest Earthquakes
(Source:USGS Earthquake Centre)
Update: 08 Sep 2010 Number of Visitors: 805582
(Since:1 Mar 2008)
Online Users: 10
Coral Reefs - Genera
| Genus | : | Montipora |
| Family Name | : | Acroporidae |
| Number of Species | : | 211 nominal species. The number of true species is unknown. |
| Characters | : | Colonies are submassive, laminar, foliaceous, encrusting, or branching. Corallites are very small. Septa are in two cycles with inward-projecting teeth. Collumelae are absent. Corallite walls and the coenesteum are porous and may be highly elaborated. Polyps are usually extended only at night. |
| Similar Genera | : | Most readily confused with Porites. |
| Notes | : | In one important aspect Montipora are unlike all other corals, there are three major differences in the structure of the coenosteum among the different species and these differences are very useful for identification. In some species the coenosteum is plain, without any elaborations, and the corallites are found either immersed in the coenosteum or situated at the base of funnel-shaped depressions. Other species develop various elaborations, or ornamentations, on their coenosteum. Different species of Montipora have different combinations of these coenosteum structures and these are used in combination with growth form characters for identification. In some species, especially those that are massive or form thick plates without additional upward growth (such as nodules or branches), there is little variations in growth form. Others show enormous variation and these are the ones that are initially difficult to identify. |
| Picture | : |  |
| Genus | : | Acropora |
| Family Name | : | Acroporidae |
| Number of Species | : | 368 nominal species. The number of true species is uknown |
| Characters | : | Colonies are usually ramose to arborescent, bushy or plate-like, rarely encrusting or submassive. Corallites are two types, axial and radial. Septa are usually in two cycles. Columellae are absent. Corallite walls and the coenosteum are porous. Polyps are usually extended only at night |
| Similar Genera | : | Only two Cyphastrea species and the ahermatypic Arcohelia have distinct axial and radial corallites |
| Notes | : | The most common growth forms of Acropora are: table-or plate like; colonies are flat, either with one central leg or attached to the substrate at one side. Pillow-like; colonies are composed of fine branches and grow as thick pillow-like clumps. Arborescent; colonies are composed of tree-like branches. Corymbose; colonies are composed of horizontal anastoming branches inclined at varying angles. Digitate; colonies are composed of short non-dividing, non-anastomosing branches like the fingers of a hand |
| Picture | : |  |
| Genus | : | Anacropora |
| Family Name | : | Acroporidae |
| Number of Species | : | 10 nominal species, six true species |
| Characters | : | Colonies are arborescent with thin tapered branches, without axial corallites. Al corallites are radial, and are small and immersed. Septa are in two cycles with inward-projecting teeth. Columellae are absent. Corallite walls and the coenosteum are porous, without elaborations. Polyps are extended day and night and are widely spaced; they are small, with fine tentacles |
| Similar Genera | : | Anacropora has Montipora like corallites combined with an Acroporalike arborescent growth form. Unlike Acropora, there are no terminal corallites |
| Notes | : | Anacropora are essentially branching Montipora. They have no axial corallites like the Acropora; rather, new corallites are budded from the smooth tissue of the branch tip. The result, in comparison with Acropora, is a slow growing, irregular colony. Anacropora appear to be poor competitors and survive only in muddy niches usually unoccupied by other sorals. Not surprisingly, they are seldom seen by divers |
| Picture | : |  |
| Genus | : | Pavona |
| Family Name | : | Agariciidae |
| Number of Species | : | Approximately 50 nominal species at least 12 true species |
| Characters | : | Colonies are massive, laminar or foliaceou, the latter usuallyt being bifacial. Corallites have poorly defined walls. They are small shallow depressions, usually with a central columella, sometimes separated by ridges. Corallites are interconnected by prominent septo-costae. Except for P. explanulata, polyps are extended only at night |
| Similar Genera | : | Pavona is close to Leptoseris which has similar corallites but finer septo-costae |
| Notes | : | Pavona species can be divided into two groups; leafy species and non-leafy species. The former group has the greatest number of nominal species, (and perhaps true species) but these are poorly represented in Australian waters. These leafy Pavona are usually distinguished from Leptoseris by the presence of corallites on both sides of the fronds or “leaves”. |
| Picture | : |  |
| Genus | : | Leptoseris |
| Family Name | : | Agariciidae |
| Number of Species | : | 25 nominal species, approximately 14 true species |
| Characters | : | Colonies are foliaceous, sometimes laminar or encrusting, the former being usually unifacial. They frequently have a distinctive central corallite. Corallites have poorly defined walls. They are small shallow depressions with a central columella, usually separated by ridges and interconnected by fine septocostae |
| Similar Genera | : | Leptoseris is close to Pavona |
| Notes | : | Leptoseries colonies are generally found on lower reef slopes, especially under overhangs and in the openings of caverns, on lagoon floors and also on the ocean floor between reefs. Most species have a delicate leafy appearance. They are usually uncommon and found only by scuba divers |
| Picture | : |  |
| Genus | : | Euphyllia |
| Family Name | : | Caryophylliidae |
| Number of Species | : | 15 nominal species |
| Characters | : | Colonies are flanelloid, phaceloid or meandro-phaceloid, the latter usually dome-shaped. Walls are thin and imperforate. Columellae are mostly absent. Septa are prominent, smooth-edged and imperforate. Polyps are extended day and night, are large and fleshy and have tentacles whisch vary in shape for each species. Two species, E. divisa dan E. ancora, can be distinguished only by their tentacles |
| Similar Genera | : | Euphyllia and Plerogyra corolla may be similar, but living polyps are completely different |
| Notes | : | Euphyllia have separate sexes and most release gametes for external fertilisation. In equatorial localities, however, some may brood larvae.Only in Euphyllia is it mandatory to use the appearance of the living polyp to separate two species. Fortunately, these polyps are large and very distinctive. Just why the tentacles of different species have such different shapes is unknown, but it probably bears some relation to specialized feeding habits. The tentacles never have stinging cells grouped into batteries, unlike those of most corals, and they may be adapted to capturing food particles in water using mucus and cilia |
| Picture | : |  |
| Genus | : | Plerogyra |
| Family Name | : | Caryophylliidae |
| Number of Species | : | 6 nominal species, 3 true species |
| Characters | : | Colonies look like bunches of large grey grapes under water. These vesicles hide the underlying skeleton possibly have a protective function. There are no batteries of nematocysts on the “grapes” as there are on the tentacles, but nevertheless. Perogyra is one of the few corals sufficiently well armed to be able to sting a human on the back of the hand or on the arm |
| Similar Genera | : | None |
| Notes | : | None |
| Picture | : |  |
| Genus | : | Physogyra |
| Family Name | : | Caryophylliidae |
| Number of Species | : | 5 nominal species, 3 are true species |
| Characters | : | The skeleton of Physogyra is mostly constructed of thin blistery plates. It can be cut with a knife and floats easily on water when dried. Phsogyra have separate sexes and release gametes for external fertilisation |
| Similar Genera | : | Like Plerogyra, Physogyra is capable of stinging humans |
| Notes | : | Both Plerogyra nad Physogyra have similar vesicles which resemble masses of bubbles. These are smaller than those of Plerogyra, are extended during the day and can be retracted readily if disturbed |
| Picture | : |  |