Researchers of a new study found that small damsel fish grow a bigger false eye on their rear fins to distract predators and increase their chances of survival.
Survival techniques are very important for smaller animals that often fall prey to bigger predators. Different animals have different survival techniques allowing them to adapt and survive in their habitat. In a first of its kind study, researchers from Australia's ARC Centre of Excellence for Coral Reef Studies found that small damsel fish grow a bigger false eye on their rear fins to distract predators and increase their chances of survival. After growing a false eye, the fish is also capable of reducing the size of its real eyes.
Researchers have debated for a long time now on whether false eyespots, or dark circular marks on less vulnerable regions of the bodies of prey animals play an important role in protecting them from predators. In this new study, researchers confirmed that the growing of false eyespots is a survival strategy that allows the fish to confuse their predators.
"It's an amazing feat of cunning for a tiny fish. Young damsel fish are pale yellow in color and have this distinctive black circular 'eye' marking towards their tail, which fades as they mature. We figured it must serve an important purpose when they are young," Oona Lönnstedt, a graduate student at CoECRS and James Cook University, said in a press release. "We found that when young damsel fish were placed in a specially built tank where they could see and smell predatory fish without being attacked, they automatically began to grow a bigger eye spot, and their real eye became relatively smaller, compared with damsels exposed only to herbivorous fish, or isolated ones."
During the study researchers found that juvenile damsel fish with enlarged eye spots had a five times higher survival rate than fish with normal-sized eye spots. Other that growing a false eye, researchers found that when such small fish were placed in close proximity to predators they adopted other survival techniques like reducing activity levels, taking refuge more often and developing a chunkier body shape less easy for a predator to swallow.
The study titled "Predator-induced changes in the growth of eyes and false eyespots" was published in the latest issue of the journal Scientific Reports.
