Researchers found a unicorn-like horned fish in a cave. This finding came about when they surveyed cave fish of the genus Sinocyclocheilus.
Fish in this genus are found only in China, usually in small, dark ponds. There are 76 known species of Sinocyclocheilus, most of which share characteristics with the newly discovered species, including poor eyesight (some are even blind), lack of scales and no pigmentation. However, only a few Sinocyclocheilus fish have horns.
There are also a handful of Sinocyclocheilus species that live in clear waters and lack the unique features associated with their strange 'cousins'.
Researchers found a unicorn fish swimming in a small pool, measuring 1.8 meters wide and 0.8m deep, inside a cave in the mountainous province of Guizhou. The team collected the fish to be brought to the lab and examined. At first, they didn't realize there was a species they had never seen before.
It was only after comparing the fish to other known species and analyzing their DNA that researchers realized what they had found.
On further examination, as quoted from Live Science, Tuesday (7/2/2023) researchers found that these horn-like structures are very different among the species of Sinocyclocheilus that live in the dark, namely they vary in length and can be branched or unbranched as in S. longicornus .
Since the light-dwelling Sinocyclocheilus species lack horns, these appendages may have something to do with their habit of living in dark areas. The most logical explanation is that the horns help these fish to 'see' in the dark.
Most species of Sinocyclocheilus, including S. longicornus, have a fully developed lateral line. The line is an organ made of highly sensitive cells that run down the fish's body sideways and detect changes in pressure, temperature, and salinity. As a result, the horns contained in these fish are useless as a detection tool.
However, based on the new findings, the unusual size of the horns in S. longicornus coupled with the fact that the new species is not closely related to any other longhorned species, suggests that longhorns appeared on at least two separate occasions within the genus, the researchers wrote. .
In the future, by comparing the environmental conditions of S. longicornus and several other horned fish, it is hoped that it will reveal what the mysterious horns are actually used for.