Can you recommend a less cumbersome description for us to use in these exchanges about the “important life forms unknown to science we need for our well-being?”

The problem here is there is no word yet coined by a human discoverer and we do have times of awkwardness like this where we are at risk of breaking new ground in ways that bypass human scholarly endeavor we like to see, so that humans, as much as possible, are taking the lead in making advances and breaking new ground. You are doing that but only conceptually and not from a scientific effort that could more readily pin down the detailed nature of what these are and where they might fit in amongst other life forms with respect to their description, similarities and differences, compared to other life forms already known. As a consequence, you might simply call them "Novel Life Forms in Water" and leave it at that. It would be less cumbersome than a sentence length description and sets them apart from all other known life forms.