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Researchers Discover a Fish That Can Recognize Numbers and Count

By: April Carson

Archerfish, noted for their ability to shoot insects out with a spray of water, are experienced at determining the quantity of things. Biologists who trained these fish to take photos on a disk that was raised above their tank came to this conclusion.

The fish were tested in a number of ways, including the ones described above. Some individuals were rewarded for shooting at a stimulus containing fewer points than others, and vice versa.

The fish quickly adopted this pattern and correctly picked the correct set even when the number of points in the sets varied.

Different animals can estimate the number of objects

Many animals, from primates to arthropods, have a sense of number, which is the capacity to estimate the quantity of distinct things by eye, such as food items, family members, or predators.

This has been demonstrated by scientists through tests in which representatives of different species are given two sets of visual information, one with and the other without elements.

However, the results of such studies are not always interpretable in simple terms. It's conceivable that some animals involved were guided instead by the non-numerical features of their sets, including area and density, rather than the number of items.

Archerfish were taught to identify numbers and count by scientists

A group of scientists from the University of Trento, including David Potrich, have developed a more accurate method to determine whether an animal can differentiate between several visual events. The fish, nicknamed "Archerfish," were tested on by scientists (Toxotes jaculatrix). These fish are known for their ability to capture insects by striking them out of their mouths, which they may do since they live in estuaries and mangroves throughout India to Australia.

To begin, Potrich and his colleagues trained archerfish to fire water at a picture on a monitor above an aquarium in exchange for food. Then they picked out eight individuals, trained them to distinguish between two pictures with three and six points, respectively, then tested them.

In this case, you have a 100% reward rate since each player shoots the target from six points. Four more individuals received a prize if they shot the stimulus from three points, and four more – if they took aim at it from six. The training and later research stimuli were picked to ensure that their radius, area, and perimeter matched.

The authors made certain that the fish were directed by the number of points, rather than the non-numerical elements of the pictures.

After training on a spray gun, the scientists conducted three no-reward trials with 24 attempts each. The fish, who had been taught to shoot at an object from three locations, were given a selection of objects from two and three points in the first test.

Individuals who learned to select a stimulus from six points in this example must now choose between stimuli from six and nine points.

What occurred during the second study?

The experiment was repeated, but with two changes. Individuals trained to pick an object from three points were given the option of selecting items from six or nine points; and individuals trained to pick a stimulus from six positions were shown things ranging between two and three points.

Finally, in the third test, participants were given two items with five and eight dots, respectively and had to choose one.

In all three scenarios, the fish obeyed the trained rule ( p <0.001). All tests showed that fish who had been taught to choose an item from three points were more inclined to pick things with less points. In contrast, individuals who had been trained to select a stimulus from six options tended to prefer stimuli with more points.

Archerfish have shown the capacity to assess the proportion of inputs and act on this knowledge.

In the second stage, the researchers conducted an experiment in which only little amounts of items were presented. They showed the archerfish two-point and three-point items — and instructed them to select those that included three points.

In three tests with a total of 24 attempts, the fish were presented with stimuli ranging from three to six points and four to six points. Subjects were more inclined to shoot targets that had more points in both experiments (p <0.001).

The fish, like in the first part of the study, were guided by the relative rather than absolute number of objects. For other species of fish previously obtained similar benefits include the scalar (Pterophyllum scalare) and guppy (Poecilia reticulata).

The natural inclination to focus on comparative figures appears to be more appropriate for fish, which face the same problems in nature. Honey bees (Apis mellifera), on the other hand, are more inclined to rely on absolute numbers than carp.

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About the Blogger:

April Carson is the daughter of Billy Carson. She received her bachelor's degree in Social Sciences from Jacksonville University, where she was also on the Women's Basketball team. She now has a successful clothing company that specializes in organic baby clothes and other items. Take a look at their most popular fall fashions on

To read more of April's blogs, check out her website! She publishes new blogs on a daily basis, including the most helpful mommy advice and baby care tips! Follow on IG @bossbabymav







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