Although lots of sharks are singular animals, their manta ray family members are remarkably social: They copy one another’s motions, play together, and will even strangely enough technique close-by people. Now, researchers have actually found they likewise form “friendships” with their fellow rays—loose associations that can last for weeks or months at a time.
To comprehend the structure of manta ray neighborhoods, scientists tracked more than 500 groups of reef manta rays (Mobula alfredi) for 5 years in the blue-green waters off the coast of northwest Indonesia (above). They photographed the rays at 5 event areas: 3 “cleaning stations,” where the mantas got full-body manicures from cleaner wrasse and copepods, and 2 popular feeding areas, where the rays slurped up shrimp and fish larvae (and often their dependable cleaners, the copepods).
The scientists then recognized private rays from patterns of areas on their bodies and tracked their interactions. Females were more likely to form lasting associations with each other than males, who tended to prevent other males, the scientists report today in the journal Behavioral Ecology and Sociobiology.
However unlike other animals with strong social bonds (for instance, many species of dolphins) the rays did not form tight-knit groups. Rather, they formed 2 loosely associated neighborhoods, one comprised mainly of woman rays, and the other comprised of women, juveniles, and males. The groups crossed courses at feeding locations and cleaning up stations prior to private members went their own method and returned hours or days later on. That’s similar to chimpanzees, who “group up” in a different way when they are foraging or sleeping.
The rays revealed a strong choice for specific areas, with women normally investing more time at cleaning up stations and males normally investing more time in the feeding locations.