by Matt Walker Editor, BBC Earth News

The once secret life of a huge, recently discovered species of manta ray has been unveiled.

Biologist Dr Andrea Marshall has discovered that the giant fish, which she first described as new to science last year, undertakes huge journeys.

As well as making the longest migration known across the Indian Ocean, the fish gathers in large numbers to feed and survives attacks by sharks.

The behavior is revealed in the BBC documentary series Natural World.

Growing up to 7m wide, manta rays are the largest living ray in the ocean and one of the largest of all fish.

Previously, it was thought there was just one species of manta ray, known by the scientific name Manta birostris.

But the more Dr Marshall swam with them, the more she noticed how different manta rays that frequent reefs and the open ocean are, both in their behavior and markings.

Mantas evolved from sting rays, and it was thought they had lost their sting. But Dr Marshall has found that the larger ocean-going mantas have retained a vestigial sting on their tails, proving that the two are separate species.

In July last year, she announced the discovery that there are not one but two species of manta ray at the American Elasmobranch Society’s annual conference in Montreal, Canada.

Manta Ray

The larger giant mantas retain the name Manta birostris, while the reef-going mantas have been newly named Manta alfredi, in tribute to Alfred Whitley who first scientifically described manta rays in the 1930s.

However, Dr Marshall’s studies have uniquely revealed a host of manta ray behaviors.

The rays sometimes swim across the ocean floor, skimming the reefs with their mouths, a behavior filmed by the camera crew for the first time.

Usually the fish feed on plankton, but what they feed on when skimming is unclear.

Dr Marshall studies manta rays off the coast of Tofo in southern Mozambique.

It was always thought that manta rays stayed in shallow waters.

Manta ray mating behavior

But Dr Marshall has discovered that the larger giant species of manta ray dives deeply, and migrates 700 miles (1,100km) in just 60 days to the Maldives, the longest migration known for a fish living in the Indian Ocean.

In the Maldives, researchers have also uncovered a unique gathering place of reef mantas, where hundreds of the fish gather.

Around 80% of the fish are female, with many pregnant, suggesting the area is a critical breeding site for the species.

Studies by Dr Marshall and colleague Dr Simon Pierce of the Manta Ray and Whale Shark Research Centre based at Tofo Beach in southern Mozambique have also revealed that manta rays living off Tofo bear huge scars inflicted by large sharks.

Mysterious giants

Manta rays appear capable of surviving such attacks and will queue up to have their wounds tended by cleaner fish, which nibble at the wound to remove dead tissue and prevent infection.

Dr Marshall’s studies have also revealed new aspects to the fishes’ reproduction.

Many male mantas follow a single female, mirroring her behavior in a bid to attract her as a mate.

Females, which give birth to a single pup after a 12-month gestation, rarely give birth in consecutive years, Dr Marshall has found.

That extremely slow reproduction could place the fish in danger from overfishing, both for subsistence and for export to be used in traditional Chinese medicines.

A new diving season has arrive in the Maldives…

For more information on diving holidays, visit Maldives Dive Travel now!

The Maldives, an island nation located in the Indian Ocean and comprised of over 1000 atolls, features some of the world’s best scuba diving sites…

Maldives Diving Season

Iruvai, the North-East Monsoon, brings with her the Maldivian dry season, ushering in a distinct diving season.

Maldives Weather

The Indian Ocean has a great effect on the climate in Maldives by acting as a heat buffer; absorbing, storing, and slowly releasing the tropical heat. The temperature of the Maldives ranges between 24°C and 33°C throughout the year. Although the humidity is relatively high, the constant cool sea breezes keep the air moving and the heat mitigated.

The weather in the Maldives is affected by the large landmass of South Asia to the north. The presence of this landmass causes differential heating of land and water. These factors set off a rush of moisture-rich air from the Indian Ocean over South Asia, resulting in the southwest monsoon.

Two seasons dominate Maldives’ weather: The dry season, associated with the winter northeast monsoon “IRUVAI,” and the rainy season, brought by the summer southwest monsoon “HULHANGU.”

According to the traditional Maldivian calendar, the IRUVAI begins in December with typically strong, unsettled winds and rough seas that gradually travel down the Maldives from the north. It is divided into nine “Nakaiy,” or periods, with the last “Nakaiy” finishing in April. The “Iruvai” brings the driest weather period to the Maldives, where the air possesses a comparatively short sea track compared with that during the remainder of the year.

Diver hooked on the reef using a current hook

Currents in the Maldives

The exposure of the Maldives to the vast Indian Ocean ensures that an immense body of water is constantly flowing across the plateau on which these atolls are built. Oceanic currents are largely influenced by the direction of the trade winds. They flow from the NE to SW during the Iruvai and from SW to NE during the Hulhangu. They are of great strength, where currents in the channels near Male’ have been recorded at four knots or more.

Tidal currents flow according to the height of the tide and the direction of the prevailing winds, and are said to be much weaker than oceanic currents, though they causes velocity variations in the flow. At the atoll passages, current streams can be quite irregular due to the islands, reefs and sandy shoals.

Best Time to Dive in the Maldives

The North-East Monsoon is considered the best period to dive in the Maldives, as a result of continuous flowing of water into the atolls, especially the channels the feature clear water and lots of food for the pelagic creatures, such as the gray reef shark and the whale shark.

Due to the continuous flow of the North-East Monsoon current, the visibility becomes crystal clear, which is why this is one of the best times to go scuba diving in the Maldives.

Felidhu Atoll

The Felidhu Atoll, within the range of liveaboard diving, is often visited during the North-East Monsoon due to the high possibility of spotting some larger marine life.

Almost all the dive sites are channels in local “Kandu” based dives. The incoming current attracts lager fish and channel crossing has become a common way of performing dives in these channels. The entrances of the channels are at a depth of 28 to 30 meters and the width of these channel are no more than 150 meters.

Gray Reef Shark

Maldives Fish Life

Due to the North-East Monsoon‘s currents, the channels’ entrances are attractive to bigger fish, such as gray reef sharks, white tip reef sharks, schooling silver jack fish, tuna, schools of eagle ray and many more.

Early morning dives to hammerhead shark point “Fotteyo Kandu” is also a highlight during this season. Hammerheads are not only seen during the early morning hours here, but have also been seen by divers during the day.

Channels like Miyaru Kandu, Devana Kandu, Diggiri Kandu and Alimatha Dekunu Kandu are also well known among the liveaboards.

In addition to Felidu Atoll, other atolls, North and South Male’, Ari atoll, Meenu atoll and Baa atoll are also considered to be excellent diving sites during the North-East Monsoon.

If you are booked for a diving holiday this season, I strongly recommend that all the divers possess a current hook, have your scuba gear tuned up and get ready for a new season of diving in the Maldives!

For more information on diving holidays, visit Maldives Dive Travel now!

Amphiprion nigripes, also known as the Black finned anemone fish or Maldives anemone fish, is a clown fish of the genus Amphiprion. The Maldives own anemonefish, not know from anywhere else except nearby Sri Lanka.

Anemone fishes are specialized damselfishes that have adapted to living in a symbiotic relationship with anemones, and to such extend that they are rarely seen away from their host. There are about 30 species, all except one in the genus Amphiprion, 3 of which know from the Maldives.

Maldives own Black Finned Anemone fish

They can be found through most of the Indo- pacific and of the 1000 or so anemone species. The anemone doesn’t sting the fish as it recognizes it as being part of itself. Anemone fish feed on food drifting past and diet comprises zoo-plankton but may also nibble on algae growing coral bases nearby.

This clownfish is characterized by its rusty, orange color with a single white stripe running vertically just behind the eye. It can attain a maximum length of 4.3in. (11cm).

The Black finned Anemone fish is found in the Western Indian Ocean among the coral reefs of the Maldive Islands and Sri Lanka. It is often associated with the magnificent sea anemone, and typically lives in small groups. Black Finned Anemone is widely distributed all around reefs of Maldives and can be found at reef crests and slopes to depth of about 15 meters.

The destination Maldives together with the Maldives resorts and companies have been nominated in the 16th World Travel Awards regional ceremony to be held at the Grosvenor House, A JW Marriot Hotel in London on 7th November 2009.

This year’s nominees for the Indian Ocean have been announced in the World Travel Awards website where by the nominees will be given awards based on the voting’s by travel agents worldwide.

The Maldives has been nominated as the Indian Ocean’s Leading Destination, whilst The Male’ International Airport has been nominated as the Indian Ocean’s Leading Airport. Comoros, Madagascar, Mauritius, Seychelles and Sri Lanka are competing against Maldives under Indian Ocean’s Leading Destination category.

Hailed by the Wall Street Journal as the “Travel industry’s equivalent to the Oscar’s”, the World Travel Awards are the most comprehensive and most prestigious awards program in the global travel industry. The World Travel Awards were established in 1993 to acknowledge and celebrate excellence in the world’s travel and tourism industry.

The winners of the World Travel Awards are based on thousands of votes cast by travel professionals from 167,000 travel agencies in over 160 countries across the globe.

The voting for this year’s Indian Ocean Awards is open until 14th August 2009. Votes can be casted by registering and logging into the voting system available at www.worldtravelawards.com.

Last year Maldives won the Indian Ocean’s Leading Destinations Award and World’s Most Romantic Destination awards while Maldives Tourism industry won awards in many categories.