Red-bellied river creature — hidden among stones — found in China. It’s a new species
At the mouth of the South China Sea behind Hong Kong, the Pearl River meets the ocean, pouring fresh water into the salty waves.
The Pearl River Basin extends across southern China with smaller rivers feeding its current.
In one of these tributaries, boulders and chunks of granite dot the river and provide refuge to creatures below the surface.
One of these creatures is Opsariichthys rubriventris, a fish recently discovered as a new species, according to a study published Sept. 27 in the peer-reviewed journal Diversity.
Many fish were collected from the river, including six adult males and three adult females of the new species, according to the study.
The holotype — or specimen used to describe the species as a whole — is a 2.6-inch-long cyprinid, the family of fish that includes minnows and carp, researchers said.
“The new species has a silver-gray body on both sides, turning silvery-white from below the lateral line,” researchers said.
The young fish have three vertical “irregular blue-green stripes,” but older fish develop up to seven stripes, two of which are thicker than the others, according to the study.
Adult males also go through a color change during the mating season, researchers said. From the lower jaw to the back of the fish, it takes on a bright orange-red color, extending onto the fins.
The color earns the species its name from Latin words ruber, meaning red, and venter, meaning belly.
Males also develop what are called “pearl organs” on their head during mating season. They appear in rows on the cheeks and can have a “cone-shaped” structure, according to the study.
“This species lives in the upper reaches of clear water with moderate velocity, in streams with a bottom composed of small to medium-sized granite and boulders or sand and gravel,” researchers said.
The fish’s body shape is tied to its environment, researchers said, and it has a “streamlined body for agile maneuverability within stream confines.”
The new species was found in Guangdong Province in southeastern China.
The research team includes Jia-Bo Chen, Ying-Tao Li, Jia-Jun Zhou, Cheng Li, Guo-Xi Weng, Hung-Du Lin and Jun-Jie Wang.
This story was originally published October 15, 2024 at 1:54 PM with the headline "Red-bellied river creature — hidden among stones — found in China. It’s a new species."
