Morris the cleaner shrimp becomes lunch

[JesterAAK]

I added a cleaner shrimp and a red fire shrimp to my tank today. They both were doing fine, acclimated them and everything. I went upstairs to take care of some stuff and when I came down I noticed that my cleaner shrimp was in 2 pieces and had become quite the smorgoshbord for the rest of my fish.

It appeared as though the shrimp started molting and while vulnerable became lunch. Is this possible? I believe this is the case as the red fire shrimp was ok. If not, are shrimp normally vulnerable to getting eaten? And if so, under what conditions do shrimp molt?

 

[becky_e]

What fish do you have? All the fish I want would leave larger inverts alone, but some do see them as lunch!

 

[mogurnda]

They normally molt every few weeks to a month, depending on feeding and conditions. Often shrimp will molt prematurely in response to stress (like transport), which can be lethal. They will also initiate an early molt in response to loss of an appendage.

Before a molt, the animals cease feeding for a day or two. Mine usually molt at night, and are very shy for the next day or so while their exoskeleton hardens.

There is persistent lore regarding the role of iodine. Some say it induces unhealthy, early molts, others say it's necessary for molting. I have combed the literature for any experimental evidence for either effect and have come up empty.

 

[JesterAAK]

Damsels, Cardinal, Hippo Tang, and a north atlantic killie.

I noticed an appendage in the bag when I put the shrimp in the tank, so this probably caused him to molt in which case he became lunch for my fish.

Thanks guys.

 

[mogurnda]

Usually it takes a little longer (on the order of days) for a crustacean to molt in response to losing an appendage. If the shrimp was damaged in transit, it may have just been dying and the fish helped finish it off.