Porcelain crab disease???

madmito15 · Mar 23, 2022

After much digging with no luck, I’ve registered just today to ask a question! My porcelain crab seems to have white spots that have developed over the last two weeks

other inhabitants have no sign of ich so I’ve weeded that out. Not sure how old she is but is behaving normally. The spots first developed in her claw but have spread to the inside of both claw legs and the top of her shell. 13 gal bio cube was a rescue tank that was established for 3-4 years and only cared for 1-2 times a year. All readings were super high but I’ve gotten them back to zero with a substrate change and water changes. Normal care is weekly water changes and 1/4 substrate vacuum. Original inhabitants were two clowns and the porcelain. I’ve added a CUC, pistol shrimp and watchman goby over the last three months. Ph= 8.3. Anyone have any ideas??

blaxsun · Mar 23, 2022

None, but I suspect next time it molts that'll take care of it.

DaJMasta · Mar 24, 2022

Do you have similar ones elsewhere on the rocks or glass? Could be starting spirorbid worms just growing on its shell. I don't know if there's much to do in any case, but if its behavior seems normal, you should probably just wait and see.

Fishfreak2009 · Mar 24, 2022

madmito15 said:
After much digging with no luck, I’ve registered just today to ask a question! My porcelain crab seems to have white spots that have developed over the last two weeks other inhabitants have no sign of ich so I’ve weeded that out. Not sure how old she is but is behaving normally. The spots first developed in her claw but have spread to the inside of both claw legs and the top of her shell. 13 gal bio cube was a rescue tank that was established for 3-4 years and only cared for 1-2 times a year. All readings were super high but I’ve gotten them back to zero with a substrate change and water changes. Normal care is weekly water changes and 1/4 substrate vacuum. Original inhabitants were two clowns and the porcelain. I’ve added a CUC, pistol shrimp and watchman goby over the last three months. Ph= 8.3. Anyone have any ideas??

Crustaceans cannot get ich. It is a protozoal parasite of fish. Most likely something trying to grow on the shell, perhaps a spirobid worm like previously mentioned. I would expect it to disappear the next time your crab molts.

My only other suggestion is to check your iodine level. Crustaceans need iodine to properly molt, and some corals tend to deplete it as they grow (especially zoanthids IME)