"En madi" means "manta ray" in the Dhivehi language (Maldivian).
Manta Rays of the Maldives
The Maldives archipelago contains an estimated 10,000 individual manta rays - the world's largest known population of manta rays. This population primarily consists of the smaller Reef Manta Ray (Manta alfredi), but the larger Oceanic Manta Ray (Manta birostris) is occasionally seen, which accounts for less than 1% of mantas reported. Pre-2009, all mantas were designated under the species Manta birostris, but research into the Maldives population by The Manta Ecology Project, which commenced in 2001, has contributed to the current scientific opinion that there are at least two species of Manta.
The majority of mantas appear to remain resident of an atoll, moving from east to west and back with the changes of prevailing monsoons each year, and will be most likely reported at sites on the leeside to the prevailing winds. For example, mantas are commonly reported at Lankan reef site on the east side of North Malé Atoll from April to November. The same mantas have also been reported around Boduhithi, on the west side of the atoll, from December to March.
It is unknown how long mantas live, but based on photo-identification of a well-known North Malé Atoll manta known as "Brenda" since the mid-1980's, it is known she is at least 36 years old, and likely to be significantly older. Mantas in aquaria may have one pup per year from a pregnancy. However, in the Maldives adult female mantas become pregnant much less frequently than this (every 3-5 years may be more typical) but the reason is unknown. Generally, female mantas are larger than male mantas although male mantas may grow as large as females.
There appears to be two mating seasons in the Maldives consisting of four-week periods around October/November and March. These periods occur just before the changes in the prevailing monsoon and are probably connected to increased plankton productivity, which appears to occur at these times. During these periods it is common to observe chains of males chasing females in their attempts to impress the female with their swimming prowess.
It appears that mantas do not establish long-term relationships and form groups, but they aggregate when feeding and behave co-operatively. Some examples of social learning have been described yet new-born mantas are left to fend for themselves as there is no maternal care of offspring.
Although mantas are pelagic and spent most of their time in the epipelagic and pelagic zones, large numbers of mantas are commonly reported in-shore during these times at either cleaning or feeding areas where they are easily observed by divers and snorkellers. However, mantas remain around the Maldives archipelago throughout the year, with individuals regularly travelling between atolls. Some mantas appear to perform long-distance migrations, traversing the entire length Maldives. One manta ray first observed in Ari atoll, in the centre of the Maldives , was subsequently observed in the northernmost atoll of Haa Alifu; the sites are 270 km apart.
Although our knowledge on Manta species has significantly increased in the past 10 years, there is still much that is unknown.
Manta Ecology Project, Manta Research
Identify Your Manta
With world's largest known population of manta rays, the Maldives is the most reliable place to study these amazing animals. Since the Maldivian Manta Ray Project (MMRP) began in 2005, over 3,000 different individual manta rays from more than 25,000 sightings have been recorded. It is possible to identify every individual because each has its own unique pattern of black spots on their predominantly white ventral (belly) surface. Just like a fingerprint, these patterns do not change throughout the lives of the mantas, enabling each individual to be tracked as it is sighted over the decades. Every new manta, or a re-sighted individual, helps to better understand the population size, composition, migratory routes, reproductive output, native ranges, and areas of critical habitats - all of which are important in developing effective management and conservation strategies.
The area between the branchial gill slits and abdominal region is used for the identification of mantas.