I have a species that have evolved from their world's equivalent of deep (~3 kilometres deep) sea snails, specifically from they resemble the Scaly-Foot Gastrobpod. The Xeno-ocean is salty/has a significant concentration of conductors/electrolytes dissolved in the water (similar to our ocean).
I want their present day form to be
- land dwelling
- communicate biologically via radio signal
- with a body size roughly that of a dog (small or large)
They presently (i.e. on land) have another form of communication, a sort of radula clicking speech. But I'd like to understand how their deep sea ancestors communicated via radio wave, to form an idea how they communicate now.
That Wikipedia page (and others) doesn't go into enough detail for me to know if the sort of radio waves a species could evolve would attenuate after 10 mm or 10 meters. The lower part of that range is not useful for submarines, and the upper only for radio-controlled ones (which is seems to be the focus of articles on Wikipedia), but would be the difference between the species being able to use radio waves underwater or nor.
The reason I'm asking here, and not on Physics, is because even if there is a range of frequencies, if the antenna/transmitter required to communicate at various distances required unrealistic power levels or antenna bigger than is reasonable for a dog sized creature ( I mention that because some submarines use a very long trailing wire as an antenna, which violates the dog-sized requirement above ).