Snorkeling with 50 manta rays

The first of my two days off (on island) turned cold and I did not expect to snorkel given the prediction of 2 meter ocean swells. As sometimes the case the prediction of the ocean swell was exaggerated or had not occurred yet so at 10:45 this morning I climbed aboard the glass bottom boat determined to brave the cold (19C?) and look at mantas from the boat. I dressed in my shortie wet suit just in case I wanted to snorkel and with mantas all around us I could not resist. Of course the water was warmer than the air and what a fabulous experience!!  I feel very fortunate to have such a great place to swim.

Manta rays were busy feeding on the plankton and came within an arms reach. Such graceful, mysterious looking creatures. Once again I want to share a little info on these fish that are hard to see most of the time and here I was watching one after the other swim next to me, below me and veer off course to avoid a collision with me. There is no danger, manta rays do not have the barb of the sting ray and since they are filter feeders they cannot bite you. 

Courtesy of Wikipedia (plus my comments), the species I am looking at is

 M. alfredi which reaches about 5.5 m wingtip to wingtip (18 ft).^[21] Dorsally, mantas are typically black or dark in color with pale markings on their "shoulders". Ventrally, they are usually white or pale with distinctive dark markings by which individual mantas can be recognized.^[8] (over 700 individuals photographed  around Lady Elliot and identified by Project Manta)
Mantas move through the water by the wing-like movements of their pectoral fins, which drive water backwards. Their large mouths are rectangular, and face forward as opposed to other ray and skate species with downward-facing mouths. Mantas must swim continuously to keep oxygenated water passing over their gills. Mantas track down prey with visual and olfactory senses. They have one of the highest brain-to-body mass ratios of all fish.

 

 

Manta alfredi group in the Maldives

6] ^[17] Manta rays may live for as long as 50 years.

 

Manta alfredi foraging with mouth opened wide and cephalic fins spread

As filter feeders, manta rays consume large quantities of zooplankton in the form of shrimp, krill and planktonic crabs. An individual manta eats about 13% of its body weight each week. When foraging, it slowly swims around its prey, herding it into a tight "ball" and then speeds through the bunched organisms with a wide-open mouth.^{[20] 0]} As many as fifty individual fish may gather at a single, plankton-rich feeding site.^[10] Mantas are themselves preyed upon by large sharks and by killer whales. They may also be bitten by cookiecutter sharks,^[22]:17 and harbor parasitic copepods.^[22]:14

Manta alfredi at a coral reef cleaning station with fish picking off parasites

Mantas visit cleaning stations on coral reefs for the removal of external parasites. The ray adopts a near-stationary position close to the coral surface for several minutes while the cleaner fish consume the attached organisms. Such visits most frequently occur when the tide is high.^[34]Individual mantas may revisit the same cleaning station or feeding area repeatedly^[35] and appear to have cognitive maps of their environment.^[23]
Mantas are found in tropical and sub-tropical waters in all the world's major oceans