Southeast Asia's aquatic ecosystems contain a sharpshooter that could instantly target prey in the vicinity. The animal, known as the archerfish, is commonly found in the region's mangrove forests.
The swimmer can emit water from its mouth with a powerful force and high accuracy. Its skill is commonly utilized to shoot down bugs for a tasty meal.
Archerfish and Their Water Jet
The archerfish does not fire its water jet indiscriminately. Before the attack, the swimmer will distinguish the target from the confusing features of the environment. University of Oxford's visual ecology expert Cait Newport said in a Science report the scientists first thought that the processing power of the archerfish brain is limited due to its tiny size.
The complicated skill baffled the scholars for years, but a recent study offers a possible explanation. In the study, Ben-Gurion University of the Negev's Zlotowski Center for Neuroscience expert Ronen Segev and his team carried out a series of experiments that tested the ability of the archerfish.
The authors trained five archerfish to shoot the programmed images on a screen facing toward their tanks. The images included in the study are motionless, grayscale pictures. This phase was added with moving squares that serve as targets. Each time the water jets hit the blinking targets successfully, the archerfish are rewarded with pellet treats.
The archerfish group eventually learned the process. After the familiarization, the subjects were then exposed to images with white backgrounds. This time, the rewards are only given if they shoot insects instead of plants and flowers.
The last phase included the exposure of the archerfish to 800 pairs of images they had never encountered yet. The images included a set with pictures of a single insect and a nonanimal material. According to the findings, the archerfish could shoot insects at approximately 70 percent.
Complex Thinking Capacity of Archerfish
A separate group trained to shoot at just images of plants was similarly accurate with the animal shooters, hitting the nonanimals successfully at 70 percent. Both groups were observed to apply their initial familiarization to determine prey from plants.
A previous study was carried out to find how the archerfish distinguish objects and count numbers. However, the analysis around the shapes and figures was not much detailed.
A computer model was utilized for it to think like the archerfish. According to the authors, the model suggested that the particular swimmers rely on shapes to tell if it is a potential target or not. In addition, the texture of the insects is not essential when the archerfish analyze their prey.
Throughout the examinations, presenting images of the plant and insect silhouettes were more helpful for the archerfish than the texture-based surface images of the objects. The authors emphasized that the images used in the tests were motionless and grayscale.
The study concludes that the archerfish hunt their prey in the wild without movement and color. But Segev believes that the sharpshooter of Southeast Asia uses an advantage more than just the shapes of the insects.
The study was published in the Journal of Experimental Biology, titled "Recognition of natural objects in the archerfish."
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