Scientists have discovered previously unknown features of the “legs” that characterize the chanterelle, an unusual fish. Recent research suggests that it uses its legs to scan and taste the bottom in search of food.
Carolina chanterelle (Prionotus carolinus) inhabits the western coast of the North Atlantic. It can be found from Nova Scotia, Canada, to the Gulf of Mexico. This aquatic vertebrate has six “legs” that are formed from transformed fins. As scientists have found, legs are used not only to move on the seabed, but also play a key role in searching for food.
Details of two studies on the unusual structure of the chanterelle were published at the end of September in the scientific journal “Current Biology”.
Extraordinary sense organs
Scientists accidentally came across the Carolina chanterelles during a trip to the Marine Biological Laboratory in Woods Hole, Massachusetts. They noticed that other fish followed the chanterelles as they moved along the bottom – apparently due to their ability to discover buried prey. They then took several specimens to the lab to learn more.
In one of two new studies, experts found that the “legs” of chanterelles are covered with sensory papillae, each of which is heavily innervated with sensory input. The papillae also have taste receptors and exhibit chemical sensitivity that prompts fish to dig. It has been confirmed that chanterelles can detect and locate ground and filtered mussel extract and even single amino acids.
– This fish grew “legs” thanks to the same genes that developed our legs – and then used this body part to find prey, using the same genes that our tongues use to taste food. “It's very crazy,” says Nicholas Bellono of Harvard University in Cambridge.
Carolingian chanterelleShutterstock
Chanterelle legs have different characteristics in other species
During the study, scientists also acquired another species of chanterelle – Priotonus evolans. It has been observed that as long as Prionotus carolinus, that is, the Carolina chanterelle digs to find prey hidden in the mud and is very sensitive to touch and chemical signals – this P. evolans it lacks these sensory abilities and uses its legs for locomotion and probing, but not digging.
– We were surprised to see how much the chanterelles differ from each other in terms of the sensory structures on their legs. This system therefore exhibits many levels of evolutionary innovation, emphasizes David Kingsley from Stanford University
The researcher points out the differences between chanterelles and most other fish, between individual species of chanterelles, from structure and sensory organs to behavior.
Ancient Gen
In the second study, the researchers took a deeper look at the genetic basis of the fish's unique “legs.” To do this, they used genome sequencing, transcriptional profiling, and hybrid species research to understand the molecular and developmental basis of leg formation.
Analyzes identified an ancient and conserved transcription factor, called tbx3a, as a key determinant of sensory leg development. Genome editing confirmed that they depend on this regulatory gene to develop their legs normally. The same gene also plays a key role in the formation of sensory papillae and the tendency to dig.
Further research could explain many mysteries
According to scientists, thanks to further research on chanterelles, we will be able to learn more about human evolution and how the ability to walk upright evolved.
“Although many traits look new, they are usually built on genes and modules that have existed for a long time,” Kingsley says.
As the authors emphasize, the findings regarding chanterelles indicate that it is now possible to expand our detailed knowledge of complex traits and their evolution in wild organisms, and not only in well-established model organisms. Now the authors want to learn more about the specific genetic and genomic changes that led to the evolution of chanterelles.
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