In my earlier blogs I wrote about the new manta ray that arrived to the Atlantis Aquarium during my stay. It is a very rare event even in the life of the aquarium, so I thought I would tell you more about this special occasion. Only very few aquariums are able to keep manta rays around the world, these animals require special care.  So how did she arrive to the aquarium and how she accommodated to the new environment?

On that day I have just finished my presentation that I gave to the aquarium staff on my proposed research so they know why I will hang around the manta tank in the next few weeks and they could also share their valuable experiences about the mantas they kept previously.  At the time of my arrival they had Poseidon for a while in the ruin tank, the huge male Manta birostris that I was planning to study in the next few weeks.

So just when I told the last few sentences to my excited audience they got an urgent phone call from their boat that was cruising a few miles away from Nassau to collect some smaller fish for their exhibit: they spotted a small manta ray…. and in just a few hours the small manta ray was safely lifted into the aquarium exhibit.

I was in the water immediately with her and with one of the aquarium leading scientist and we followed her to make sure she stays safe. As the manta ray was introduced to a new environment, even if the size of the tank is enormous, the animal eventually faced a border (wall, window) that was completely unnatural. The biggest difficulty of keeping manta rays in captivity is that many of them are unable to get used to the walls. This individual was however able to accommodate to the new environment very fast luckily which was a huge relief for all of us.

The next problem to solve was to train her to feed: basically `spoonfeed` her from a bucket from the surface.

She made several attempts from the beginning to feed naturally, swam with opened mouth, using her cephalic fins to lead plankton into her mouth, sometimes she even did barrel rolls as well.

Since there are thousands of other fish swimming in the same tank it was hard for her to find any food with this technique. To make sure she got her daily food targeted feeding was necessary.

The training started with one of the aquarists approaching her from behind attempting to feed her by pouring a bag of shrimp into her mouth in the feeding area, so she knows where to expect food. Later a huge syringe was used to try to navigate some shrimp into her mouth in order to lead her up with it close to the surface.

She learned eventually that food can be expected in a certain area of the tank and she started barell-rolling when we poured shrimp into the water there.   

As she barrel rolled we increased the concentration of the food near the surface by pouring the food out of the bucket. Therefore she approached the bucket on the surface, so from that point she just had to stay on the surface swimming with open mouth in order to get the food delivered in her mouth. As the following videos show, with the help of a talented aquarist she was finally trained to take the food from the bucket on the surface.

http://www.youtube.com/watch?v=LiY_koGSnbo
http://www.youtube.com/watch?v=b4uYixvxsGI

And after the initial success she continued performing the learned behavior.