Spitting in public places is prohibited, especially today when the pandemic requires us to follow a series of preventive measures that could ease the curve of transmission. Although there is a strict rule among humans over the production of saliva-based bodily fluids, this specific archerfish disregards the mandate.
Toxotes jaculatrix: Spitting Fish
Psychology and cognitive scientists from the University of Trento studied one particular marine animal with a unique ability above the rest of the fish species. The Toxotes jaculatrix, better known as the archerfish, can propel water jets out of itself to target potential prey on sight. In the new study, the authors have seemingly taught the fish another unique talent that could add to its skillset.
According to the research, the archerfish learned how to spit on computerized screens, exhibiting their newfound ability to identify numbers.
Although the Toxotes jaculatrix showed promising results from controlled trials, previous animals already presented their ability to count or comprehend the existence of numbers. DailyMail reported that mammals, birds, and other fish species are among the animals found with number-related skills.
However, there is a debate over the past experiments that led to the lack of confirmation about the cognition of animals over numbers. On one occasion, fishes previously examined were suspected of relying on the presence of their large school size and not by counting. A separate study also showed that fishes could have relied on the size of their choices rather than the number of contents inside.
To determine if fish could count numbers, the new study fabricated the process of the previous research. This time, choices were supplied with various sizes and shuffled positions. The investigation was successful, and the authors concluded that the archerfish have truly exhibited the skill in counting.
Can Archerfish Species Count?
The Toxotes jaculatrix is known in the fishing community as the banded fish. Formally, the species is called the archerfish, which is commonly found in waters with considerable rates of salinity. The archerfish is endemic in many regions of Indo-Pacific Asia, and fortunately, is far from being extinct, unlike other fish groups.
It could grow larger than the average size of gilled swimmers, reaching a maximum scale of 7.9 inches in length. The ability of the archerfish to spit is also stunning. When it emits water jets from its mouth, the Toxotes jaculatrix could target prey as far as 59 inches away.
University of Trento's Center for Mind/Brain Sciences expert and author of the study Davide Potrich said in a report by New Scientist that there are doubts over the fishes' familiarity with number sentences, as those comprehensions are of different fields compared to the continuous properties found in the species.
Potrich added that there were many studies that attempted to solve this problem. However, past investigations' approach and corresponding information did not contain the complete data required. To grab better results from the new experiments, the authors controlled variables that were not number-related as strictly as possible. The screens placed in front of the archerfish tanks served as the medium of data.
On the screens, choices of dots appeared, which the archerfish selects through spitting. After a series of trials, the fish were familiarized with the numbers they were exposed to. To secure a non-biased selection, each of the dots shown on the screen was analyzed by a program to be distinct from each other. In conclusion, the archerfish can comprehend relative numbers but tend to select larger or smaller choices for several instances in the experiments. The pre-print coverage of the study was published in the journal bioRxiv, titled "Archerfish number discrimination."
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