This is in a 10 gallon, all are rescued fish, I understand and agree the tank isn't fit yet, I cant get a tank or other fish right now cause of shut down. The rainbow shark acted funny when this happened, it was hiding under the sponge filter for a half day now is back to normal, it's a Gloshark to be exact, I read it's rare for them to even spawn in captivity?Hello and welcome to the forum!
It could very possibly be eggs from the rainbow shark. Does the female look bloated? (Aka filled with eggs?)
What size is the tank? I do see a problem here. Pea puffers should be kept with their own species. Tiger barbs should be kept in groups of 6 or more and rainbow sharks need quite a big tank.