If you are an avid diver I am sure you have heard about manta rays. These gigantic peaceful fish are unique in so many ways. Starting with just their size; they can grow to be 5m to 7.5m from wing tip to wing tip! They are estimated to be around 130kg per meter. Thats a massive animal! They can also can live to be up to 50 years old!
To picture what these massive beings look like, I like to picture sort of an underwater bat slowly flying through the water. They have a general diamond shape, with two flaps called cephalic fins at the tip of their head and a large forward facing mouth. When they feed, these fins hang in front of their mouths and act as funnels to drive more plankton into their mouths. When they’re not feeding these fins are curled up and look like horns. This is the reason mantas used to be called devil rays. Moving to the other end of this beautiful creature, mantas have a long tail similar to stingrays. Unlike stingrays though, there is no barb or stinger at the base of the tail. So despite their intimidating size, they are completely harmless.
There are a few ways to tell whether a manta is male or female. In the manta world, females are large and in charge. Besides size, there is another way to tell which gender the manta is. If you look at the base of their tails you will see either two things. If its a female, there will be two flaps beside the tail. If it’s a male there will still be those two flaps but in between the flaps and the tail, there will be these two finger like protrusions called claspers. One on each side of the tail. These are his boy parts, he gets two…
If you look underneath a mantas belly, you’ll notice these black spots. These spots are all individual to each manta. They act as a sort of fingerprint and helps us identify each manta. There are over 1,500 mantas on the coast of Maldives!
Lets move on to their eating habits. Manta rays eat around 5% of their body weight daily. They eat zooplankton in large quantities generally at night, though they have have been spotted feeding during the day. When they do feed however, they do something called a feeding circle where they do big backflips to maximize the amount of food they get in one pass. Their massive gills on their underside help them filter out unwanted things they may have gotten into their mouths. Their tiny esophagus ensures the do not get any small fish in their digestive track.
Not much is known about the manta’s reproductive habits, besides this thing we call a heat trail. This is how you know if a female is in heat. You will see a big female swim by, followed by 4 or 5 males trying to chase her down. The gestation period for a manta pup is about 12 to 13 months. The pups start off in an egg and grow to a rather large size. Once the egg hatches, the pup remains inside the mother receiving nutrients until its resembles a small adult. Once they are mature enough, about 1m across or so, they are shot out like a big burrito and require no further parental care.