scleractinia

Plerogyra sinuosa

Commonly known as the grape, bladder, pearl or branching bubble coral Plerogyra sinuosa is a species of “bubble coral” that is distributed throughout the Indian and Pacific Oceans, ranging from the Red Sea to the West and Central Pacific Ocean. P. sinuosa’s bubbles will vary in size and will increase/decrease depending on the amount of light available. With them being larger during the day and smaller at night, as it will make room for its tentacles to reach out to capture food.

Classification

Animalia-Cnidaria-Anthozoa-Scleractinia-Caryophylliidae-Plerogyra-P. sinuosa

Image: RevolverOcelot

Branching Flowerpot Coral - Alveopora sp.

They are not flowers but a coral colony. Alveopora (Scleractinia - Poritidae) is a genus of stony corals with at leas 27 nominal species, all of them native to the Indo-Pacific.

These corals create branched and massive skeletal formations, which are light and porous. They are generally clear coffee, cream or green, and can have shades of pale pink, yellow or blue. Their oral disc and the tips of the tentacles can be green or white. The contrasting color of the oral disc and tentacles give them the look of  flowers. 

Alveopora possess 12 tentacles and their corallites have 12 septa. Polyps may reach 30 cm long or more. The Branching Flowerpot Corals extend their polyps both during the day and partially at night.

References: [1] - [2]

Photo credit: ©Daniel Stoupin | Locality: Australia

NEW REEF CORAL SPECIES FROM FRENCH POLYNESIA

 The new species Echinophyllia tarae is described from the remote and poorly studied Gambier Islands, French Polynesia. Although the new species is common in the lagoon of Gambier Islands, its occurrence elsewhere is unknown. Echinophyllia tarae lives in protected reef habitats and was observed between 5 and 20 m depth. It is a zooxanthellate species which commonly grows on dead coral fragments, which are also covered by crustose coralline algae and fleshy macroalgae.

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“Flower Pot Coral” (Genus: Goniopora)

Goniopora is a genus of colonial stony coral which occurs in lagoons and areas with turbid water conditions throughout the Arabian Sea, Indian Ocean and various tropical and subtropical areas of the Pacific Ocean. Like other colonial stony corals Goniopora spp. are carnivorous and will feed on passing invertebrates and organic matter which are caught by their stinging nematocysts. 

Classification

Animalia-Cnidaria-Anthozoa-Hexacorallia-Scleractinia-Portidae-Goniopora

Images: Peter Young Gho, MD and Gdiggers

Scleractinian Sex

Sorry nerds, this post isn’t full of x-rated fanfic about an alien race - instead it’s a jumping point for understanding how stony corals reproduce!! (Which, by the way, is allll over the board.) Earlier today I tackled a new chapter from my textbook and freaked on the vocabulary required to read about sex. “The majority of studied corals are simultaneous hermaphroditic broadcast spawners.” WTF does that mean? Let’s break it down.

Gonochoric: Individuals are either only male or only female.

Hermaphroditic: Individuals are made up of both sexes. Types of hermaphroditism include:

  • Simultaneous: Both sexes are present at the same time.
  • Sequential: Starts out as one sex and changes to the other. Protandrous hermaphrodites go from male to female, while Protogynous herms start as females and switch to male.

Dioecious: When an individual is functionally only male or only female for the duration of its life.

Bidirectional Sex Change: When an individual can switch back and forth from male to female to male to female to male to…

Broadcast Spawning: Corals release separate male and female gametes into the sea for external fertilization and development.

Brooding: Corals breed embryos and planulae larva inside of their polyps, not to be released until a later development stage.

Fecundity: The ability of an organism to produce young in great numbers. (The word means “fruitfulness” or “fertility.”)

Now in English! Most corals make babies asexually by producing both sperm and eggs inside their polyps at the same time. They are released into the ocean to mix and develop, after which the larvae - called planula - settle out, find a hard surface to attach to, and start up a whole new colony.

Note that I said most… the weird part about coral sex is that any combination of the reproduction styles listed above may occur in colonies around the world. They’ve evolved a huge variety of tactics to perpetuate the species types, generally due to changing ocean currents, water depth, and the range of environmental factors found in different ocean areas. Goniastrea favulus even sneezes out a gross mucus of negatively buoyant eggs that sits on the coral head, until it switches gender and sperm is released! (Sadly, I could not find a cool pic of this snot bubble anywhere on the web.) It turns out that stony coral reproduction is more complex than we could have imagined. Good thing they don’t experience emotions.

References

  • Z. Dubinsky and N. Stambler (eds.). Coral Reefs: An Ecosystem in Transition. Springer. 552p DOI: 10.1007/978-94-007-0114-4_6.
  • Image Credit: Hickerson/FGBNMS
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Orange Cup Coral (Tubastraea coccinea)

Sometimes known as the sun coral, the orange cup coral is a species of Dendrophylliid stony coral which is native to the Indo-Pacific region. However, it has been introduced to much of the Atlantic and the Caribbean Sea. T. coccinea will typically inhabit shaded vertical surfaces and caverns, and like other cnidarians are predators, feeding on passing food items.

Classification

Animalia-Cnidaria-Anthozoa-Scleractinia-Dendrophylliidae-Tubastraea-T. coccinea

Images: Nick Hobgood and Alexander Vasenin

Duncanopsammia axifuga

Duncan Coral

Kingdom:Animalia
Phylum:Cnidaria
Class:Anthozoa
Order:Scleractinia
Family: Dendrophylliidae


The Duncan Coral is a stony coral with large fleshy polyps that have pink tentacles and a green center. It grows on reefs in the Indo-Pacific. (This specimen is Australian.) They are primarily photosynthetic, but benefit from occasional feedings. The colonies grow by sprouting from the coral itself. (There is a very small polyp coming from the base of the larger polyp. Little is known about how corals age, but they can live to be centuries old. This is a very easy coral to keep, and is quite beautiful.

Grooved Brain Coral (Diploria labyrinthiformis)

..a species of Faviid stony coral which occurs in tropical areas in the west Atlantic Ocean, the Gulf of Mexico, and the Caribbean Sea. Grooved brain corals typically inhabit offshore reefs at depths ranging from 1 to 30 meters. Like other corals grooved brain corals are suspension feeders and feed mainly on zooplankton an bacteria, which are captured by polyps which extrude mesenterial tentacles. Diploria labyrinthiformis also host zooxanthella which produce nutrients for the coral via photosynthesis. 

Classification 

Animalia-Cnidaria-Anthozoa-Scleractinia-Faviidae-Diploria-D. labyrinthiformis

Image: Janderk

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Chinese Lettuce Coral

Mycedium elephantotus (Scleractinia - Pectiniidae), better known as Chinese Lettuce Coral, is a stony coral growing vertically in fragile, fan-like plates.

Colonies of M. elephantotus generally form tiers or whorl-like structures; corallites (the hard calcareous skeletons secreted by the individual polyps) are rounded, raised above the colony surface and have a distinctly ‘nose-shaped’ appearance. Colonies occur in attractive shades of green, purple and pink.

The polyps are extended only at night. They do not have tentacles, instead obtaining food by rapidly engulfing organic matter in a layer of mucus which coats the surface of the colony.

This coral is found on reefs in the Red Sea, the Gulf of Aden, the Indian Ocean, around South-east Asia, Japan and the South China Sea, off the coast of Australia and in the west and central Pacific Ocean.

References: [1] - [2]

Photo credit: ©Blogie |  [Top] - [Bottom]

Locality: Angel’s Cove, Talikud Island, Philippines (about 12m depth)

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Boulder Star Coral (Montastrea annularis)

…a endangered species of “brain coral” (Faviidae) which occurs in the western Atlantic Ocean, where it is one of the most abundant and thoroughly studied species of reef-building coral species in the Caribbean. Like other coral species Montastrea annularis is both colonial and carnivorous, with polyps extending their tentacles at night to feed on passing organisms. 

Classification

Animalia-Cnidaria-Anthozoa-Scleractinia-Faviidae-Montastraea-M. annularis

Image: Louiswray and Jstuby

Green Brain Coral - Goniastrea sp.

What you see in this photo is a live Green Brain Coral of the genus Goniastrea (Scleractinia - Faviidae), which is widespread in the Indo-Pacific forming massive mounds, thick encrusting colonies or may tend towards columns. Colonies are common in sub-tidal and some inter-tidal areas.

The corallites of Goniastrea vary from single-mouth, rounded with shared walls through to multiple-mouth, weakly meandering with thin shared walls.  Corallites are neat with fine, uniform septa (purple in the photo).

Technique: Phase contrast illumination

Reference: [1]

Photo credit: ©James H. Nicholson | Olympus BioScapes International Digital Imaging Competition (2011)

Pólipos de Montastraea cavernosa | ©Guillermo Jordán-Garza

The Great Star coral, Montastraea cavernosa, is a colonial coral species which grows in encrusting plate forms or, more usually, as massive rounded domes.

This species is present on both sides of the Atlantic Ocean. It is widely distributed throughout the Caribbean, Gulf of Mexico, Bahamas and Bermuda and also found along a section of the west coast of Africa between Mauritania and Gabon.

Cnidaria - Anthozoa - Hexacorallia - Scleractinia - Faviidae - Montastrea - M. cavernosa 

Source and more information.