Ocean fish adapted to a bottom lifestyle and moving with the help of six appendages resembling legs have shown a previously unstudied and relatively new evolutionary process. An international team of scientists analyzed how seacocks use their “legs” and concluded that the appendages are similar to olfactory organs.

Modern research in the field of evolution continues to reveal new details about the origin and development of various species, including humans. Authors of a recent scientific study revisited old monkey videos and found that these animals could pronounce some words in human speech. Another publication showed that queen ants, unlike worker ants, learn to eat sick offspring and “recycle” the resulting nutrients by using them for reproduction. This made it possible to adapt to a certain lifestyle in which the queen leaves the nest and can carry infected larvae out.

Experts from Harvard University, Stanford University, Roger Williams University (all in the US), the Max Planck Society (Germany) and the University of Genoa (Italy) analyzed why seacocks have “legs” and how these oceanic fish exemplify the mechanisms. Scientific articles on the function and appearance of the plug-ins in question were published by the magazine. Current Biology.

The seacock’s “legs” are actually extensions of their six pectoral fins. They allow you to act so skillfully that other fish, as a rule, communicate with seacocks and steal their prey.

Scientists who observed seacocks hunting in captivity discovered that these fish swim and “walk” for short periods. They also scratched the surface of the sand to discover molluscs beneath the sand layer, sometimes without visual cues. Since seacocks easily found even specially buried capsules containing certain chemicals, the researchers concluded that the “legs” of the fish are sensitive not only to mechanical, but also to chemical stimuli.

In addition, the authors of the scientific article accidentally discovered another species of seacocks that use “legs” for movement and exploration, but do not know how to find and extract prey hidden in the sand. In the middle of the research, the team of scientists took a different group of fish from the ones they knew for experiments. As a result, the first species was named. Prionotus carolinusand the second — Prionotus evolans.

Seacocks that know how to dig have scapula-shaped “legs”, covered with special protrusions – analogues of taste buds, “papillae”. In fish that moved and explored the ocean floor only with the help of “legs”, the appendages were in the form of sticks without protrusions. After comparing seacock specimens in the Museum of Comparative Zoology, scientists came to the conclusion that “papilla” can be considered a relatively new and characteristic example of evolutionary specialization for the inhabitants of only a few places – one-sided development organism with maximum adaptation to environmental conditions.

According to the authors of the article, it is possible to examine in more detail how evolution helps adapt to certain conditions using the example of “walking” fish. Genetic factors that control the development of seacocks’ “legs” may also be responsible for the emergence of limbs in other organisms, especially humans.