Electroporation is a phenomenon where electricity is used to open up small temporary pores within cells. The purpose of this is to deliver medicine, DNA, bacteria or whatever desired substance into cells in a way that won't destroy the cells. Since electricity is the basis of this process, scientists in Japan wondered if electric eels could cause the same effect of electroporation in other living organisms. To test this, zebra fish larvae were put into a tank with an electric eel. DNA with a gene that would make the fish glow green was put into the tank. The eel was fed a goldfish, which caused it to emit 185-volt pulses into the water. A day after, some of the fish larvae started to glow, which lasted for about 3-7 days. This affected 5% of the larvae, and it suggests that electric eels are able to cause electroporation. However since this was done in a lab, it's not definitive that this effect occurs out in the wild.
The phenomenon described in this article reminds me of the electrophoresis lab. In that lab electricity was used to transport genetic material across a medium, using the slight negative charge of DNA to move it towards a more positively charged source. Electroporation is similar but it involves the process of opening up cells in order to take up a desired substance. The article suggested that electric eels may cause genetic modification and diversity. However it concedes that the scientists who conducted the experiment can't conclusively say that because the experiment was done in a lab. Genetic modification due to electric eels hasn't been observed out in nature to my knowledge. I personally don't understand electricity too well and how shocks from an electric eel would affect its surrounding area. But I know that when these eels use electricity, it's usually with the purpose of killing some nearby animal that they're defending themselves from or trying to hunt. So while the experiment suggests the eels may cause electroporation leading to DNA take up, I doubt it's very common due an organism being killed by the eel by being too close to it.
Article: https://www.smithsonianmag.com/smart-news/eels-can-genetically-modify-nearby-fish-with-their-electrical-pulses-180983422/
Article about electroporation: https://www.technologynetworks.com/cell-science/articles/an-introduction-to-electroporation-a-tool-for-transfection-and-competent-cell-generation-363195
