Boy, that girl was hardly showing when I saw her last February. I couldn't even tell she was pregnant, and by then, she was a good 8 months along. The mother of all manta rays, Big Bertha, gave birth this summer to possibly two baby manta rays.
Manta rays can grow up to 20 feet--wing-tip to wing-tip--and Big Bertha isn't called Big Bertha for no reason. (While they are closely related to sting rays, but they do not have stingers; just a long, skinny tail that looks like one!) Mantas weigh about 100 pounds for every foot of wingspan.
What's interesting about manta rays--well, actually, there's so much that's interesting about manta rays, but for our purposes here, I'll stick to one. It's the birth. In the scientific world, it's called aplacental and viviparity. That is, manta rays give live birth without a placenta. Here's how it works: The pup hatches from its thin-shelled egg while it's still inside its mother. After hatching, the pups feed on the uterine milk until it's expelled from its mother. At that time, the pups measure three to four feet wide and weigh approximately 20 pounds. Their pectoral fins are curled around the pup in an s-shape and unfold into wings when they are born. They bond with their mother is broken, and they instantly and magically start swimming and living on their own.
What's amazing is videographer James L. Wing captured Big Bertha's pregnancy--he didn't get the actual birth, though--throughout her 13-month gestation. The video above includes courtship behavior with two different males on two different occasions.
Hmm, I'm headed to Hawaii (Big) Island next week. I feel an adventure coming on!