Does anyone know about specific shrimp illnesses? Is there a good resource for non-fish, non-coral aquarium animal disease?

Background: My buddy Chip had two skunk cleaner shrimp and a blood shrimp (Ninong, that would be two Lysmata amboinensis and one Lysmata debelius) in his 55 gallon tank for several months. They were doing very well, grew nice and big. The blood shrimp even survived 10 days without power after hurricane Wilma with a resulting nitrogen spike that killed everything else in the tank. The shrimp were always active in the midst of any activity going on in the tank and seemed to enjoy cleaning fingertips in addition to the fish. The skunk shrimp produced eggs rather frequently. Chip (H. sapiens) added a pistol shrimp (Alpheus sp.) along with a watchman goby (Cryptocentrus sp. [formerly known as Gobius sp.]) about two months ago. Although the pistol shrimp was rarely seen, evidence for fresh excavations could be seen on a daily basis in the sand (Carib Sea aragonite sand) around the live rocks. The goby is doing fine and is fat and happy munching down on any food put in the tank - pellet, live or frozen brine, Cyclop-eze, etc.) The shrimp were also pigs (Sus sp.) at feeding time.

Chip added several peppermint shrimp (Lysmata wurdemanni) last week to help combat a number of small Aiptasia anemones that started to appear a few weeks after assassinating three large Aiptasia anemones two weeks earlier by injection with lemon juice (total lemon juice injected = 1.5 cc via insulin syringe and 25 g needle).

What went down next: The day after adding the peppermint shrimp, only one of them was visible. That was the last he saw of the peppermints. Starting 4 days ago, he found one of the skunk shrimp dead on the bottom of the tank. No apparent trauma. The next day he found the blood shrimp dead. Yesterday he found the second skunk shrimp dead. There are no fresh excavations for several days around the rocks.

All the fish look and act normally, the BTA is doing fine, the giant feather duster, snails, and hermits are all OK. Water parameters check out within normal limits.

This appears to be a fatal shrimp specific condition or disease. Any ideas?