Ever wondered how electric fish got their electricity producing organs? According to a new scientific report, published this week in Science, all the six different lineages of electric fish, which happen to have evolved independently from one another, made use of a single “genetic toolbox” to come up with their ability to generate electric power. The organ in question also helps them defend themselves against predators, predate in their own turn, navigate the waters, and communicate. The study in question was helmed by Michael Sussman (University of Wisconsin – Madison), Harold Zakon (University of Texas – Austin) and Manoj Samanta (Systemix Institute, Redmond, WA).
The study confirms Charles Darwin’s assumption regarding convergent evolution in electric fish. According to Darwin’s hypothesis, certain species of animals can develop similar features, even though they are not genetically related. In the case of electric fish, there are six different lineages, which have developed in environments as different as the Amazonian forests and the ocean. The study’s co-lead author, Jason Gallant, assistant professor at Michigan State University, explained in the press release that accompanied the publication of the report that the researchers were surprised to learn of the species’ use of the very same “genetic toolbox”. Even though they developed apart, their similar electric organ was built through the use of the same genetic sequence.
In order to complete the study, the scientists collected complete genomes from the strongest species of electric eel and electric fish. They also gathered the genetic sequences used to build electric organs and skeletal muscles in three independently developed electric fish lineages. According to Zakon, a neuroscience and biology professor at The University of Texas at Austin’s College of Natural Sciences, some of the genes involved in this process can help transform regular muscle tissue into an organ capable of generating electricity. Another important aspect of the research results is that they point to “steps in various cellular pathways that are the most likely to evolve in other animals as well. For example, the pathways that transmit electrical pulses in the vertebrate heart, including our own heart, derive from muscles. We find that electric organs in fish and these pathways in our hearts share some of the same regulatory genes.”
Electric fish use their electricity generating organ in “murky environments” underwater, for a number of reasons. They navigate the waters, stun their prey, and communicate with other members of their species, with which they then mate. Electric eels can generate up to 600 volts in electric fields, which is roughly about 100 volts per foot of fish.
