For 30 years, researchers have been aware that some fish would release chemicals into the water. Now for the first time, the chemicals are probed to be studied.
Researchers from USask discovered that wild fish release chemicals to signal other fish about dangers that are nearby. Such dangers that trigger "disturbance cues" include predators.
The scientists have observed that in the presence of familiar fish, disturbance cues are released more frequently. On the other hand, the fish would release fewer chemicals when they are in the presence of strangers or when they are on their own.
The fright response provoked by the signal is a set of behavior that includes freezing, suddenly dashing about, and shoaling very tightly together. This behavior has been used by fish to defend themselves against predators.
The voluntary release of disturbance cues is triggered once the prey has been chased, stressed, or startled by predators. Kevin Barios-Novak, A graduate student and member of the research team, explained that in the research, they observed the behavior of fathead minnows which they collected from a lake.The wild fish were separated into tanks to simulate three realistic environment settings and situations.
The fathead minnows, a species of temperate freshwater fish, can be found throughout a large area of North America. The wild fish has a conservation status rated as "least concern." The said species are ostariophysan fish, which are a type of fish known to release an alarm substance that is sent as a signal to nearby fish.
The team then grouped some of the test subjects into a tank with familiar fish, the others with unfamiliar fish, and the rest were isolated into separate tanks.
Later, the research team simulated a predator chase to which the fish responded by freezing, dashing about, or shoaling together. This only happens when a group they knew released the signal detected.
However, the fish did not take any significant defensive action when they received the cues from unfamiliar fish, as with the fish that was isolated.
Maud Ferrari, a behavioral ecologist in the Veterinary Colleges Department of the Veterinary Biomedical Sciences and the supervisor of Barios-Novak, expressed his excitement in the discovery of a new signaling pathway in animals where the fish were able to manipulate the behavior of other nearby individuals by issuing a signal.
The group pointed out that their findings may have implications for fish conservation efforts around the globe. To satisfy a goal as huge as conservation efforts, more research and preparation would be needed.
