I gave them 96% suitability (mostly their favorite foliage)
I wonder if they have any favorite foliage! I just tried all the foliage, and they like it all. With a 40 sq tank, and 11 small ocean rocks & depth >5, I tried all sorts of combinations of foliage. With 8 in the tank, it didn't matter which ones, or if there were 8 different ones. The only one that didn't give 100% suitability was the sargassum - they didn't dislike it, just not quite as high. Opening up the dolphin in APE, it does show a tank size minimum of 80 (animal density is 20) - perhaps that will increase chances of offspring?