A large group of over 9000 species, mostly marine animals. They are radially symmetrical and have a ring of tentacles surrounding the mouth of each polyp. The tentacles are armed with microscopic stinging structures called nematocysts. These contain toxic mixtures of proteins and phenols.
Ceriantharians, often mistaken for anemones, have greatly elongate bodies adapted for living within a soft mucus tube secreted by the animal. Tube anemones are bottom dwelling solitary animals that are actually more related to black corals than they are to sea anemones. They are inhabitants of areas of soft sediment. Cerianthids live in elongated tubes made of thread like specialized cells interwoven with mucus. Two rings of tentacles surround the mouth - an inner ring of short tentacles and an outer ring of long slender tentacles.
Sea anemones are solitary polyps. Many reach one-half meter in diameter and are often brightly colored. The largest species are found in the tropics and are usually attached to rocks, shells or corals; others live in mud, sand or on shells. Although essentially sessile animals, many species are capable of slowly "walking" along the ocean floor.
Often mistaken for anemones. Are considered intermediate between sea anemones and hard corals. Being virtually identical to hard corals anatomically, but without a skeleton as in anemones. In several species, numerous solitary polyps live crowded together, forming aggregations that may cover large areas of hard substratum.
Gorgonians or horny corals usually prefer waters exceeding 10 meters in depth and are less frequent in shallower areas. Sea fans are usually brightly colored, on ledges and overhangs in deeper waters.
On Philippine reefs the fire coral (Millepora Sp.) is the most conspicuous. Easily mistaken for Scleractinians (true stony corals) as their outward appearance is similar to other hard coral. Common in shallow areas, they are recognizable by the predominantly rusty surface color and a yellow or cream color on the edges. Most forms have planar interwoven surfaces; some have solid plates, others are branching, and some are encrusting and lack interlocking planes. This great morphological variation has produced a great deal of taxonomic confusion. Because of this, the number of valid species is at present undetermined, although approximately 50 species have been described worldwide. Fire corals should not be touched because they often cause an irritation or skin rash that can persist.
Comprise the single most significant feature of any coral reef. The variety of shapes, formations, colors and textures is almost unlimited. 430 or more species are known to occur in the Philippines, most of which are reef forming (hermatypic). Twelve coral species are endemic and are only known to occur on Philippine reefs. Both polyp configuration and growth form are influenced by such environmental factors as currents, salinity, light intensity, temperature, physical space and possibly, competition among various species. Most hermatypic corals require adequate light intensity and are therefore usually restricted to shallow waters (less than 50 meters deep), depending on water clarity.
The coastal waters of the Philippines harbor a remarkable variety of Scleractinian coral species. A widespread family, the Acroporidae, has two very common genera, Montipora and Acropora. Acropora accounts for up to 50% of the entire living coral surface areas in many Philippine reefs. This coral sometimes has a table like shape and is often called "Table Coral," "Staghorn Coral," or simply "Branching Coral." Another large family, the Poritidae, with 20 species, includes the genus Porites, which covers approximately 20% of some coral areas. It includes the common, massive brown "Hump Corals," which look like small mountains, as well as various branching types.
Soft corals are a numerous, extremely varied and colorful group. The polyps form a massive, mushroom shaped, or lobed colonies, but without a hard calcium carbonate skeleton. Thus, most are soft to the touch, slightly slimy, and have the appearance of fingers jutting upward, some soft and undulating, others stiff, leathery and or rubbery. The polyps are usually visible, but retract in response to sudden changes in light intensity, water movement or when touched.
Phylum Cnidaria (Coral Like Animals)
Order Scleractinia (Hard Corals, Stony Corals) (Philippine Translation: Gasang)
Uncategorized: (1) (2) (3) (4) (5) (6) (7)
(?) Briareum Sp. Thick encrusting mats give rise to crowded polyps with slender grass green tentacles. Polyp calyces less than 5mm in height. The encrusting mat is tan to violet in color. Often covering extensive horizontal or vertical surfaces, up to one square meter or more in area. common on ledges and slopes. Depths 5.20 meters. (1)
Family Acroporidae
Acropora Sp. (Branching, Table, Staghorn Coral)
Table Coral: This coral may form mats of up to a meter in size in moderately exposed reefs. (1)
Staghorn Coral: Grows in shrub like clumps and provides shelter for a variety of small fish.
Branching Coral: (1)
Family Dendrophylliidae (Tree Coral)
Tubastraea Sp. (Red Cave Coral) Has a raised calice and protruding tentacles typical of the tree coral family. (1) (2) (3)
Tubastraea Micrantha Sp. (Green Tree Coral) Often forms tall branched colonies (over 1 meter in height) with numerous cylindrical polyp tubes. The tubes are often apricot colored with a greenish sheen or are uniformly dark green. The extended polyps are green or apricot colored, often extended during the day but quickly retract when disturbed. Frequently encountered on reef flats or slopes with strong prevailing currents. The nudibranch Phestilla Melanobrachia feeds on this coral. (1) (2) (3)
Turbinaria Sp. (Disc Coral, Chalice Coral) Colonies vary in shape depending on where they grow. (1) (2)
Family Fungiidae (Solitary Corals)
Fungia Sp. (Mushroom Coral) Is solitary, oval and disc shaped. Resembles other solitary genera. Often cover entire reef areas, sitting loose on the sand or another coral. These corals break loose from the substrate and are capable of moving slowly about the rocky or coral bottom. (1)
Cycloseris Patelliformis Sp. (Hermit Coral) Small solitary or unattached corals nearly circular in shape and are usually found on bottoms away from reefs. (1)
Herpolitha Limax Sp. Corals are elongate-ovoid with prominent raised central region. A medial longitudinal groove is evident. The septa have smooth margins. Color is often greenish brown. Infrequently encountered in protected areas of rubble or sandy bottom. (1)
Family Caryophyllidae
Euphyllia Ancora Sp. (Anchor Coral) Identified by the anchor shaped tips of its fleshy polyps, which when exposed may completely cover the underlying skeleton. (1) (2)
Plerogyra Sinuosa Sp. (Round Bubble Coral) Has colonies that are like clusters of gray green grapes and is one of the few stony coral polyps capable of stinging human skin. (1)
Physogyra Lichtensteini (Tipped Bubble Coral) The tipped bubble coral has swollen and pointed tentacles and are commonly seen on moderately exposed slopes. (1)
Family Pocilloporidae
Seriatopora Hystrix Sp. (Needle Coral / Bush Coral) Normally forms fragile, dense and bushy growths with fine sharp points on the branches. (1)
Family Pectiniidae
Pectinia Lactuca Sp. (Common Lettuce Coral) It is abundant on sheltered reef slopes, it is usually brown with occasional white edges and tips. (1)
Family Agariciidae
Pachyseris Rugosa Sp. (Serpent Coral) Forms brown tinted irregular clumps with prominent ridges and is commonly seen on reef slopes. (1)
Order Alcyonacea (Soft Corals)
Family Nephtheidae
Dendronephthya Sp. (Tree Coral) The polyps appear as clusters with protruding calcareous spicules, which are clearly visible in the fleshy walls of the fully expanded animal. (1)
Family Alcyoniidae (Flower Soft Corals, Hand Corals)
Sinularia Sp. (Slimy Leather Coral) Distinguished b the very long, slender, tube like lobes, which can be extremely slimy and flabby, often seen undulating in areas of current or surge. Colony color is white, grayish, or tan to brownish. This species is similar in appearance to S. Procera and S. Sandensis. The three species can only be distinguished positively by comparing sclerites. (1)
Sarcophyton Sp. (Mushroom Leather Coral) At least 36 species of the genus Sarcophyton are common members of shallow water reef flat communities. Intertidal to at least 30m in depth. Fed on by the nudibranch Phyllodesmium Magnum and, the ovulid snails Calpurnus Lacteus and Ovula Ovum. (1) (2) (3)
Family Nidaliidae
Siphonogorgia Godeffroyi. Sp. Soft corals with a gorgonian like appearance. Colonies are bicolored: vivid red or wine red with white to yellow polyps. Frequently encountered inhabitant of reef slopes, vertical surfaces, and overhangs. Depth: 10-20m. (1)
Family Xeniidae
Xenia Sp. (Hand Coral) Over forty species of Xenia occur throughout much of the Indo-Pacific. Nudibranchs of the genus Phyllodesmium feed on Xenia. Intertidal to at least 15m in depth. (1) (2) (3) (4)
Class Anthozoa (Sea Anemones, Corals)
Alicia Sansibarensis Sp. (Tuberculate Night Anemone) With tentacles that are extremely long, thin, and string like. Color is mostly transparent white with orange in the column. This unusual anemone is observed at night. (1)
Order Cerianthria (Tube Anemones)
Cerianthus Sp. (Tube Anemone) Mostly nocturnal, anemone like animals inhabiting tough but flexible tubes. Tube anemones do not have hard skeletons like corals. Two separate rings of tentacles surround the mouth, unlike the sea anemones and their relatives that have only one ring. Three genera (Cerianthus, Pachycerianthus, and Arachnanthus) with several species each are probably the most commonly encountered. Positive identification (even to genus level) is impossible without examination of internal anatomy. (1) (2) (3) (4) (5)
Order Actinaria (Sea Anemones)
Family Actinodendriidae
Actinodendron Sp. (Branching Anemone) Bushy, low growing anemones, often somewhat flattened. The tentacles are large and are covered with grape like clusters of short knobby vesicles. Color is usually light green. Frequently encountered on sand, fully emerged during daylight. (1)
Family Actiniidae
Entacmaea Quadricolor Sp. (Bulb Tentacle Anemone) The tentacles are inflated and bulb like, the bulb usually situated just below the tips. The column is smooth and brown in color, sometimes reddish or green. The oral disc is the same color as the tentacles, usually golden brown or greenish brown. Usually found deep in crevices with only the bulb like tentacles visible. Thirteen species of anemone fishes are known to occur in symbiosis with this anemone. (1) (2) (3) (4)
Family Stichodactylidae
Heteractis Crispa Sp. (Leathery Sea Anemone) Large anemones sometimes over on half meter in diameter. Tentacles are long, slender and sinuous (up to 100 mm in length), tapered to a point at the tips, often greenish or violet. No less than 14 species of anemone fishes are recorded as symbiotic associates with this anemone. (1)
Order Corallimorpharia (Disc Anemones, Corallimorpharians)
Family Actinodiacidae
Amplexidiscus Fenestrafer Sp. (Disc Anemone) Fully expanded animals form plate like discs up to 30cm or more in diameter, with a smooth, often light colored ring near the margin. The central portion of the disc is covered with short cylindrical tentacles. Contracted individuals are rounded and bowl like. This is the largest recorded species of corallimorpharins. Common on shallow reef flats. (1) (2) (3)
Discosoma Sp. Has pale yellow tipped tentacles that are sometimes extended and forms dense aggregations on reef slopes and areas of vertical relief. (1)
Family Corallimorphidae
Pseudocorynactis Sp. Distinctive anemone like animals. The oral disc is smooth with radiating lines, usually 5-10 cm in diameter. The numerous tentacles are mostly clear or tan and transparent with golden to orange, ball shaped tips. Frequently encountered in crevices on reef slopes. (1)
Order Gorgonacia
Uncategorized: (1) (2) (3) (4) (5)
Sub Order Holaxonia (Sea Whips, Sea Fans, Gorgonians)
Acalycigorgia Sp. Branches are often sinuous. Colonies are often brightly colored: mostly scarlet red, yellow, rust orange, or deep purple. Frequently encountered in deeper parts of reefs, below the shallow reef flats, often on vertical walls; mostly at depths greater than 10 meters. (1) (2)
Sub Order Scleraxonia (Gorgonian Sea Fans)
Melithaea Sp. Large sea fans up to 1-2 meters in height, intricately branched in one plane with robust trunk and main stems. Color variable, sometimes bicolored. Mostly yellow, orange, or red. Commonly encountered on vertical walls and steep slopes. From 10-50 meters. (1) (2) (3)
Acabaria Sp. (Gorgonian Sea Fans) Sea fans that are delicately branched in one to several planes, planar or bushy, usually 8-20 cm in height. Color often vivid and variable, even within the same specimens. White, pink, yellow, orange, or red. At least 36 species have been described. On slopes and ledges. (1) (2) (3)
Class Hydrozoa (Sea Ferns, Fire Corals, Stinging Medusae)
Family Milleporidae (Fire Corals)
Millepora Sp. Due to toxins injected by the stinging cells, the aptly named fire coral is capable of inflicting very irritating stings to scantily dressed divers. Distributed throughout the tropical reefs of the world and very common throughout the Indo-Pacific. (1) (2) (3)
*Reference: Philippine Coral Reefs A Natural History Guide By Alan T. White & Coral Reef Animals Of The Indo-Pacific By Terrence M. Gosliner, David W. Beherens, Garry C. Williams
*Photos: Are Full Moon Divers. All Rights Reserved.