With the wealth of knowledge from experienced keepers here in SKF, we should have a repository of Shrimp Diseases where people can come to diagnose and hopefully find a cure to their shrimp's ailment.

Just like in the world of aquatic fish keeping where identification and diagnosis of diseases in fish and known cures are part and parcel of every aquatic forum, so should we have one for shrimp.

Vorticella

I'd like to start this database off with the not so uncommon Vorticella parasite which looks like White fungus or mould growth on the shell of the shrimp.
Vorticella is actually a protozoa of 16 known species, not a fungus at all. Vorticella are aquatic organisms, most commonly found in freshwater habitats. They attach themselves to plant detritus, rocks, algae, or animals (particularly crustaceans).
Vorticella are heterotrophic organsims. They prey on bacteria. Vorticella use their cilia to create a current of water (vortex) to direct food towards its mouth.
Typically, Vorticella reproduce via binary fission. The new organism splits from the parent and swims until it can find something on which to anchor itself.

If left untreated, vorticella have been known to cause the death of the shrimp it was attached to.

Here are examples of what it looks like.
     

Known cures: Salt bath with aquarium salts. Be careful not to use table salt with Iodine.
Dosage: 1 teaspoon to 1 cup of clean tank water (not tap water).
Duration: 30sec to 1 minute. You might need to repeat this a couple of times until the vorticella disappears, so keep the infected shrimp in a breeder or hospital tank (could be another cup of tank water).
Possible causes: Poor water conditions. Increase water change frequency.

Low doses of the salt bath have been know to be ineffective.
Ick and fungus cure meds don't work on Vorticella.
Seachem Paraguard could work as well at the full recommended dosage, since this is a parasitic med. But Seachem have admitted Paraguard isn't invertebrate safe. So only try paraguard as a last resort and drip it into the tank premixed from a bucket of tank water slowly .

This treatment is in no way a replacement for good tank husbandry.
So keep up with your water change routines, and removal debris and uneaten food.

Please add if you know of more diseases, how you cured it, what you tried that worked and what didn't work.

Cheers.