Wild manta rays are not accustomed to slow, surface swimming for a set period of time, following a meal routine or being handled by humans. So how do you train a captive giant manta to feed from a ladle and swim into a stretcher for veterinary care?
When a giant manta ray comes under an Aquarium’s care, they must find a way to ensure the animal is getting all the nourishment it needs. The Georgia Aquarium in Atlanta, Georgia, train their mantas to feed from a color-coded ladle.
Giant manta rays are primarily plankton-consuming filter feeders, but they will consume small fish as well. When feeding, this beautiful species with spread out their hornlike cephalic lobes to direct the food-rich water towards their mouth. In the wild, this species has been observed swimming in vertical loops, somersaulting and chain feeding in areas rich with food.
Check out this brief video to learn more about the process of training a manta ray to eat from a ladle straight from the experts, and view a feeding for yourself:
The manta rays at the Georgia Aquarium feed in an exhibit that also houses four whale sharks and thousands of fish. By training the manta rays to feed at a specific station in the community tank and to respond to the sound of a feeding pump, aquarium trainers are able to closely manage their mantas’ diets.
Recently the International Marine Animal Trainers Association (IMATA) published a paper in Soundings written by Dennis Christen (Curator of Animal Training and Interactive Programs at the Georgia Aquarium) and Chris Schreiber (Associate Curator of Fish and Invertebrates of the 6.4 million gallon Ocean Voyager Gallery), outlining how stretcher training facilitates a captive manta ray’s physical examinations. They reference training of two different giant mantas, Nandi and Tallulah, (Manta birostris), and the aquarium’s unique stretcher training methods.
While the animal had been [previously] conditioned to feed from a small ladle, following arrival to Atlanta a two-quart plastic ladle was established as a target stimulus. The ladle served to deliver primary reinforcement as a consequence to targeting… The mantas quickly learned to station at the ladle and to follow it as it moved throughout the holding pool and exhibit.
In a few months’ time, the aquarium team formulated a plan to condition these animals to willingly swim into a stretcher for routine health examinations. To encourage the manta ray to do so, “the manta’s feeding station was moved to the opposite end of the exhibit, she was desensitized to feeding beside large objects in the water, and subsequently approximated to swim through a mock stretcher apparatus” over a period of several months. Soon a custom-built vinyl stretcher was brought into the training regimen. Both manta rays – trained separately, one year apart – showed a positive response, voluntarily swimming into the stretcher.
Training the manta rays to swim into a stretcher wasn’t without challenges, however. Manta rays are not accustomed to swimming at slow speeds for a long period of time along the water’s surface or being handled by humans. Additionally, when they swam into the stretcher sideways or an angle, their behavior had to be redirected and reinforced to encourage swimming fully centered onto the device.
But by encouraging the manta ray’s desired movement with a food reinforcement, the aquarium is able to successfully train this important behavior used to give their mantas routine health examinations.