The Pacific elkhorn coral in-situ at Arno Atoll in the Marshall Islands.

Photo courtesy of Dean Jacobson.

The new coral species known as Pacific Elkhorn coral bears a strong resemblance to the endangered Elkhorn coral (Acropora palmata) found only in the Atlantic Ocean and primarily the Caribbean. Atlantic Elkhorn coral considered to be the primary reef building species of coral in the Caribbean has been witnessing a staggering decline over the last few years decimating almost 90-95% of this one prominent species.  This new discovery of a colony of Pacific Elkhorn coral that possesses the same divergent branching resembling an elk’s antlers was initially thought to be Elkhorn coral (Acropora palmata) but was genetically analyzed and confirmed to be a completely new species.

Dr Zoe Richards of CoECRS, the researcher who discovered this colony of coral stated that he’d never seen something like this in the Pacific before, the coral was five meters (16ft) across and nearly two meters (6.5ft) high with branches fanning out like an elk’s antlers. There are expected to be around 200 colonies of Pacific Elkhorn in this tiny patch of reef on the Arno atoll, and judging by its size, they appear to be relatively old.

The archetypal divergent branching pattern of the Pacific elkhorn closely resembles that of the Atlantic elkhorn coral - Acropora palmata. Photo courtesy of Dr Maria Beger.

The significance of this find is still uncertain, as scientist attempt to ascertain the health of this colony of Elkhorn coral to determine whether the species is healthy, or in decline. Since Elkhorn coral are known to be foundational coral reef-building species, the study of this new species may shed some light on how to save its Atlantic cousin rapidly facing extinction.

Photo courtesy ARC Centre of Excellence

Rare Pacific Elkhorn Coral Species Discovered was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Brain coral grow very slowly unlike branching varieties such as Staghorn coral and develop a strong and sturdy structure which makes them hardy against storms or hurricanes and will not break easily. It is said that they can live up to 900 years or so and the largest brain corals have been recorded to grow up to 6 feet (1.8m) in height.

Feeding on small drifting animals, Brain corals possess several tiny sweeper tentacles that lie tucked away inside their surface grooves during the day, and extend to catch food at night.  When threatened, the polyps inside the coral will retract their tentacles so that they cannot be eaten by passing predators. Apart from free floating organisms, Brain coral also receive nutrients provided by the algae which live within their tissues. The coral can also use their tentacles like hands to clean the coral surface from sand and other debris.

Divers wishing to witness a feeding brain coral which is indeed a stunning sight, should perform a night dive, and use a macro lens on their underwater cameras to capture the myriad of tiny tentacles being careful not to disturb the coral itself which will retract them at the slightest sense of a disturbance.  Most of the best Brain Coral photographs are macros or specimens isolated from the rest of the reef showing off the unique surface patterns and grooves of the coral allowing the light and shadows enhance the pattern.

There are thought to be at least 24 different types of brain coral, and often identification beyond recognizing the coral to be a Brain Coral become tricky, there are two  well known major classifications; Open Brain (Trachyphyllia) and Closed Brain Coral (Favia pallida). Open Brain Corals sometimes called Pacific Rose Coral, are usually pinched oval in shape and have two to three polyps coming off of it.

photos from flickr by: jillhudgins, jayhem, DaseinDesign, mjar81

Unraveling the Brain Coral was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

What is coral fluorescence? Well under certain light wavelengths some species of corals exhibit a phenomenon known as fluorescence where the coral itself appears to glow in shades of green, red or blue. Corals that normally appear dull brown in the daytime or under white light can take on vivid rainbow hues. Corals fluorescence when certain pigments inside them react to strong light absorbing the cooler blue end of the spectrum and reflecting back greens or reds.

The phenomenon of Coral Fluorescence is still full of mystery and the reasons why certain coral fluoresce are to this date unknown. Strangely enough not all corals fluoresce, and only a few species possesses this unique property which further complicates the search for the reason why corals glow in the first place.

There are several theories provided by scientist, and perhaps the most likely reason is that it acts as a kind of “sun block” for the coral protecting the zooxanthallae inside the coral from the harmful rays of the sun . Marine Biologists say that this property could perhaps protect shallow coral from bleaching or provide deeper coral the ability to absorb the UV light from the sun and reflect it back to the zooxanthallae allowing them to photosynthesize in the absence of sufficient sunlight.

Other fluorescence theories claim that fluorescence is an indicator of the health of coral, or is somehow used to signal coral spawning. Some scientists have also suggested that the light is used by coral to ward off predators.

Whatever the reason, for divers and underwater photographers, fluorescence is simply another unique dive experience and photo op. In order to observe this phenomenon, you will require “black light” or UV dive lights as well as your ordinary white lights to help you get around. UV lights alone are highly ineffective to navigate by, and you may end up bumping into things so use your ordinary lights till you get to the reef and then turn off the lights allowing your eyes to adjust to the darkness, while using your UV light to illuminate the coral. The process is pretty much hit and miss as not all coral pops out in vivid color. But when it does the results are simply striking. For underwater photographers coral fluorescence photography has become a  whole new fascinating sub-set of the hobby, with some photographers  switching exclusively to  capturing coral under UV light.

photos from flickr.com by shadowfall, Chris_Moody, Johnson Cameraface, Storm Crypt

The Fascinating Phenomenon of Coral Fluorescence was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Sometimes mistaken for and referred to as plants or rocks, corals are actually made up of small marine invertebrate animals known as Coral Polyps and their exoskeleton structure that acts as a home. That is we see as the hard chalky structures that join together to form coral reefs. There are two main types of coral- Hard Coral and Soft Coral.
Above photo by flickkerphotos on flickr

HARD CORAL
Hard corals are made of a rigid calcium carbonate (limestone) and appear very much like rocks. Each polyp secretes a hard exoskeleton made up of calcium carbonate and a chalky internal skeleton that stays in place even after they die. As each generation of polyps dies and their exoskeleton remains, the coral grows a bit larger and because each polyp is so small, hard corals grow at a very very slow rate. Hard corals are scientifically known as “scleractinians”.

Types of Hard Coral

Staghorn Coral

photo by Nick Hobgood on flickr

Staghorn coral (Acropora cervicornis): Staghorn coral is a branching coral with cylindrical branches ranging from a few centimeters to over 6.5 feet (2 m) in length.This coral exhibits the fastest growth of all known western Atlantic corals, with branches increasing in length by 4-8 inches (10-20 cm) per year and is one of the three most important Caribbean corals in terms of its contribution to reef growth and fish habitat.

Pillar Coral

photo by nashworld on flickr

Pillar corals (Dendrogyra cylindricus): This type of coral grows up from the sea floor, but without any secondary branching. They can grow to be up to 2.5 m (8 ft) tall. They can grow on both flat and sloping sea floors at a depth of between 1 and 20 m (65 ft). They are one of the few types of hard coral whose polyps can commonly be seen feeding during the day.

Table Coral

photo by doug.deep on flickr

Table Coral (Acropora):Table Coral is the same branching type of coral as Staghorn coral, however it grow as flat plates. The shape of table coral is ideal to expose as much of their surface as possible to sunlight. The usual color of table coral is a dull brown or green, but it is brightened up by the numerous reef fish that shelter under and around its plates.

Brain Coral

photo by bob.bachand on flickr

Brain coral (family- Faviidae): Named because of this corals spheroid shape and grooved surface which resembles an animal brain. The life span of the largest brain corals is 900 years. Colonies can grow as large as 6 or more feet (1.8 m) high.

Blue Coral

photo by Mindful One on flickr

Blue coral (Heliopora coerulea): Blue corals is named for their distinctive, permanently blue skeleton, which is generally hidden by greenish-grey or blue polyps. Blue corals occur in tropical waters, on intertidal reef flats and upper reef slopes.

Great Star Coral

photo by richard ling on flickr

Great star coral (Montastraea cavernosa): This type of coral is a colonial stony coral found in the Caribbean seas. It forms into massive boulders and sometimes develops into plates. It’s Polyps are the size of a person’s thumb and can be seen fully extend at night.

Tube Coral

photo by Nick Hobgood on flickr

Tube Coral (Tubastraea): Tube Coral is a large polyp stony coral, and is found in a variety of colors and forms depending upon species. The tubastraea faulkneri is known as the Orange Cup or Sun Coral, pictured above.

Elkhorn Coral

photo by diver_meg on flickr

Elkhorn coral (Acropora palmata): This coral is considered to be one of the most important reef-building corals in the Caribbean. This species of coral is structurally complex with many large branches. The coral structure closely resembles that of elk antlers. A popular choice as a home for lobsters, parrot-fish, snappers and other reef fish. Elkhorn coral colonies are incredibly fast growing with an average growth rate of 5 to 10 centimetres (2.0 to 3.9 in) per year and can eventually grow up to 3.7 metres (12 ft) in diameter.

Soft Corals continued in Coral Identification: Types Of Coral (Part 1)

Related Articles:
Understanding the Different Types of Reefs
Fish Identification Guides by Paul Humann
Marine Life Identification: Types of Shrimp
Clownfish Identification Part 1/2
Clownfish Identification Part 2/2

Coral Identification: Types Of Coral (Part 1- Hard Coral) was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Sometimes mistaken for and referred to as plants or rocks, corals are actually made up of small marine invertebrate animals known as Coral Polyps and their exoskeleton structure that acts as a home. That is we see as the hard chalky structures that join together to form coral reefs. There are two main types of coral- Hard Coral and Soft Coral.
Above photo by dachalan on flickr

If you missed our first past on Hard Corals and Types of Hard Coral- CLICK HERE

SOFT CORAL
Soft corals are also composed of some rigid calcium carbonate, but it is blended with protein so it is less rigid than hard corals. These corals are “rooted,” but because they have no exoskeletons, they sway back and forth with the currents, appearing to be more like plants blowing in the breeze.

Types of Soft Coral

Gorgonian (a.k.a Sea Fans)

*photos by Skinned Mink, PacificKlaus, JennyHuang on flickr

Gorgonian: This family of soft coral is also called sea whips or sea fans. Individual tiny polyps form colonies that are normally erect, flattened, branching, and reminiscent of a fan. Others may be whiplike, bushy or even encrusting. A colony can be several feet high and across but only a few inches thick. They may be brightly colured, often purple, red, or yellow. Gorgonians are found primarily in shallow waters, though some have been found at depths of several thousand feet.[1][3] The size, shape, and appearance of the gorgonians are highly correlated with their location. The more fan-shaped and flexible gorgonians tend to populate shallower areas with strong currents, while the taller, thinner, and stiffer gorgonians can be found in deeper, calmer waters.

Carnation Coral

photo by Nemo’s great uncle on flickr

Carnation Coral (Dendronephthya): Easily one of the most beautiful soft corals in the ocean the carnation coral comes in a spectacular range of colors and flourish below underhangs and caves. They are found mostly in Indo-Pacific – Islands of the Indopacific including Fiji, Tonga, Solomon Islands and the Great Barrier Reef. Unfortunately this specimen of soft coral is extremely sensitive to changes in water chemistry and is on the decline.

Toadstool Coral

photo by Paul J. Thompson on flickr

Toadstool Coral (Sarcophyton): Also known by a host of other names like Leather Coral, Mushroom Leather Coral and Trough Coral Sacrophyton corals are found in various shades of brown, with white or gold polyps. It is difficult to identify many species because they all have the similar appearance of a mushroom or toadstool, each with a distinct stalk and capitulum (cap). As they grow older, they develop a folded appearance.

Tree Corals

photo by sarsifa on flickr

Tree Corals (family-Nephtheidae): These flowery soft corals are commonly seen on many of our shores. They are usually attached to hard surfaces including boulders, jetty pilings and coral rubble. These soft corals look like bushes. The common tissue is generally rubbery but rough to the touch. A thick ‘main trunk’ attaches to a hard surface on one end, with many small branches on the other end which is why they are referred to as Tree Coral. The Carnation Coral Dendronephthya belong to this family of soft corals.

Sea Pens

photo by CW Ye on flickr

Sea Pens (cnidarians belonging to the order Pennatulacea): Sea pens are grouped with the octocorals (“soft corals”), together with sea whips and gorgonians. They were named after their feather-like appearance reminiscent of antique quill pens. Sea pens may rise up to 2 metres (6.6 ft) in some species, such as the tall sea pen (Funiculina quadrangularis) and are sometimes brightly colored. Rarely found above depths of 10 metres (33 ft), sea pens prefer deeper waters where turbulence is less likely to uproot them.

Bubble Coral

photo by CybersamX on flickr

Bubble Coral (Plerogyra sinuosa): Bubble corals have large water filled bubbles (vesicles) covering the large sharp sepia. Found in the Pacific Ocean and parts of the Red Sea, bubble coral can be seen in varying species, colors and forms. They maintain their egg-like or rather grape like appearance during the sunlit hours, then deflate at dark, manifesting finger-tentacles that feed on plankton, etc. This type of coral is sometimes referred to as Grape or Pearl Coral and also as Bladder Coral.

Related Articles:
Understanding the Different Types of Reefs
Fish Identification Guides by Paul Humann
Marine Life Identification: Types of Shrimp
Clownfish Identification Part 1/2
Clownfish Identification Part 2/2

Coral Identification: Types Of Coral (Part 2- Soft Coral) was written by Noreen for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Reef Fish Identification “Tropical Pacific”

Reef Fish Identification “Tropical Pacific” combines the incredible talents of Gerald Allen, Roger Steene, Paul Humann and Ned DeLoach four of the best marine life authors/photographers in the business. This guide covers over 2000 species of Pacific Reef Fish that inhabit the warm tropical seas between Thailand and Tahiti in a 500 page guide containing 2500 underwater photographs. Each species contains text on the fish’s common, scientific and family names, size, description, visually distinctive features, preferred habitat, typical behavior, depth range, and geographical distribution. Despite the books size making it a tricky carry-on for air travel, it’s a must have compendium for anyone visiting the Pacific.

Reef Creature Identification: Florida, Caribbean, Bahamas 2′nd Edition

Reef Creature Identification steers away from the fish and focuses on the strange and wonderful crabs, lobsters, shrimps, jellyfish, sponges, and mollusks that inhabit the reefs of the Western Atlantic. Have you ever wanted to know more about that colorful nudibranch you spotted on your dive? Or are you a shell collector that would like to know the name of your latest find?  With 448 pages and over 660 photographs, this guide covers almost every marine invertebrate of the Florida Caribbean and Bahamas region.

Reef Coral Identification “Florida Caribbean Bahamas”

We often pay more attention to identifying fish species, but often have no clue about the names and behavior of the various Coral species that make up the reef. Reef Coral Identification helps identify virtually every species of stony coral, gorgonian, fire coral and black coral inhabiting the tropical western Atlantic region. With over 530 photographs this 288 page guide will have you easily identifying all the corals you will see while diving or snorkeling the ocean just like a marine biologist. The new 2nd edition includes a comprehensive photo-essay of coral diseases and predation and a photo gallery on coral reproduction as well as information on marine pants and seaweed.

Coastal Fish Identification “2nd Edition” California to Alaska

From the beautiful cool waters of Catalina Island to the frigid straits of British Columbia this book covers it all. For more than 3 years, photographers and scientists from around the world have contributed their work to Paul Humann and Ned Deloach to aid in producing this new edition. The result of their extensive work has produced the most up-to-date, accurate and comprehensive reference available for the marine life of the tropical eastern Pacific Ocean from California to Alaska. If you’re a Monterey Bay Kelp forest diver , then this book is a must have guide.

Reef Fish Identification – Baja to Panama

Planning on a Scuba/Snorkeling vacation in Costa Rica or Cozumel?  As the title suggests the Reef Fish Identification guide Baja to Panama covers 400 species of fish that inhabit the coastal waters along the Pacific Ocean to Central America.  The guide contains 500 underwater photographs and comprehensive information regarding the fish’s distinctive features, habitat, behavior, depth range and distribution. It also includes an appendix on whales and dolphins.

Fish Identification Guides by Paul Humann was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World

Most Scuba divers who have dived in tropical or sub-tropical reefs will have been cautioned about getting stung by the notorious Fire Coral, and will have filed away the information as just one of the many things that can sting or harm you underwater.

Fire Coral also known as Stinging or Red Sea Coral belongs to the Milleporina order of species and contrary to popular belief isn’t really a coral at all. Fire corals are marine organisms that form colonies that look just like real coral; they are actually closely related to the jellyfish family and other stinging anemones.   The Fire Coral gets its name from the painful burning sting that it inflicts on the unwary diver that brushes against it.

How does it look? How can I identify Fire Coral?

Fire Coral is unfortunately rather polymorphic and can appear in several physical forms. Sometimes it appears heavily branched and delicate in appearance, other times it is more, fan-blade shaped and massive. Most common forms it appears is either branched, plated, or encrusted.   It is believed to have close to 50 varieties of Fire Coral species making it rather hard to describe. Most of the time Fire corals have a bright yellow-green and brown skeletal covering fading to a whitish hue at the tips, and will be soft and hairy  and rounded up close.

Where does it exist?

Fire Coral are widely distributed in tropical and subtropical waters. Primarily occurs in the Indian and Pacific Oceans.

Fire corals form extensive outcrops on projecting parts of the reef where the tidal currents are strong. They are also abundant on upper reef slopes and in lagoons, and occur down to depths of 40 meters.

What does it Do?

Fire Coral belongs to the family of Milleporina,  Millepora means ‘many pores’. Upon close inspection, the coral appears to have long fine hairs that protrude from the skeleton. The hairs possess clusters of stinging cells (nematocysts) that inflict the stings on human skin. These hairs capture prey, and help feed the coral.

Divers often mistake fire coral for sea weed or normal coral and may brush against it or lean on it for support. Upon contact the very small nematocysts on the corals hairs release toxins while the sharp calcified exo-skeleton cuts the divers’ skin. A fire Coral sting can cause intense pain and can be felt from two days to up to two weeks. The degree of pain varies on the duration of contact and the number of nematocysts that entered the wound.

Prevention

The best method of prevention is to practice and master Buoyancy control and avoid unnecessary contact with any coral.  Wearing full wetsuits & diving gloves is a good way to ensure you don’t accidentally get in contact with Fire Coral.

What do I do if I get stung?

The first step is to rinse the wound or affected area with salt water, as fresh water will increase the pain. Secondly use vinegar (acetic acid) or Isopropyl Alcohol to kill any remaining stinging cells clinging to your skin and help break down the toxin. Use tweezers to put out any stinging hairs. Immobilize the affected limb to prevent spreading and Finally, apply hydrocortisone cream as necessary to reduce inflammation. It is also critical to watch the wound for infection, which will have to be treated with antibiotics by a doctor.

If the diver displays symptoms like shortness of breath and swelling of the tongue, neck and face, he has probably developed an allergic reaction to the sting and should be treated for allergy and rushed to a hospital.

Photos by: Nick Hobgood, Tim Sheerman-Chase, Scary Cow, welshcathy, Paul and Jill, Craig Grobler

Playing With Fire Underwater: Fire Coral Demystified was written by Nevin for Aquaviews - SCUBA Blog - Bringing You The Other 70% Of Our World