Royal Gramma and Shrimp

[hopdude]

Have any of you had experiences with a royal gramma chowing down on your cleaner shrimp or sally lightfoot crabs. I got a royal gramma a few months ago. My two crabs subsequently disappeared (I did find remains) and my shrimp died (his antennae looked nipped).

The shrimp and crabs were all about 2 years old. Maybe they were just old?

Other tankmates: Yellow tang, 2 damsels, 2 true perculas.

Thanks!

 

[Len]

hey hopdude,
WELCOME TO REEFS.ORG!

I gotta believe it's a coincedance. Royal Grammas (Gramma loreto) is actually an ectoparasite feeder in the wild, but will supplement its diet with macro-zooplankton or any meaty foods it can scavange. It doesn't possess the anatomy to kill crabs, and I've seen them mixed with cleaner shrimps without a problem all the time. So I guess you've got a mystery on your hands.

Could it be envinromental changes? Crustaceans are sensitive to ambient conditions.

 

[Anonymous]

what are you feeding your tank and how often? is it possible that you might be underfeeding?

as you suggested, it could be that your shrimp just died of old age or natural causes and the fish was just chowing down on the remains - the circle of life, you know?

just my thoughts...

 

[Anonymous]

That is indeed odd. I think Len and coral have hit on the most probable causes.

One other (remote) possibility: have you introduced any LR recently that might contain a predator?

Let us know if you solve the riddle!

Chris

 

[tazdevil]

One other possibilty- they died during the molting process. Many factors can contribute to death then, some of which are beyond our controll (it's appraently very stressful on the individual doing it).

 

[sally1]

I have a cleaner shrimp with my royal gramma and have had no problems at all.

 

[hopdude]

Len, thanks for the welcome. I've had my tank up for about 2 years now. Just finally decided to join reefs.org.

Tazdevil, I think your theory may be the one. One of the crabs did die during molting, because I found his body mid-molt. I'm thinking old age combined with the molting process was the cause. I'm not sure how long crabs and shrimp live, but 2 years may be it. I have some soft corals in the tank that are doing great, so I don't think it was environment. No new live rock has been added.

I feed mostly Ocean Nutrition flake (Formula One, Two and Prime Reef) and seaweed selects. I usually feed once a day.

 

[Anonymous]

Don't shrimp and crabs need a trace amount of iodine in the water to assist in molting? Has anyone else heard this?

Chris