Hi everyone! We added a new nerite snail to our 5g tank along with 5 shrimp and at first he was quite the speedy little guy cleaning up the glass quite quickly. We noticed tonight he was laying on his back in the substrate and not moving. He didn't seem to respond to us picking him up but we noticed quite a bit of the substrate in the opening where his body meets the shell. Could our substrate be an issue for him? It's a fine black gravel. My husband sniffed him and he did not stink or anything. We added him yesterday morning. The shrimp all seem to be doing totally fine. I also noticed these white spots on the tip of his shell and we can't remember if they were there or not when we added him which feels really silly now but feel like we would have noticed? I moved him to a moss ledge before I left for work tonight and will check again in the morning but just wondering if this is not al behaviour? Our other nerite is darker in colour so we just see him randomly pop up in our other tank and have not noticed if he has periods of inactivity. I have tested and ammonia, nitrites are at 0. Nitrates are 10ppm. Thanks so much!