Here's an idea of what a swimming sprite would look like.
Though you're better off just using a hue to shade them lol. The last one could use that.
Maybe add some humor or make those bugs a part of the game. It is a simplest fix.
I'd say try rainbow water or just a water spray or give the water a hue, but I've said these types of solutions before.
You could try getting people to go on a bug hunt lol. See how many glitches they find hehe.