IOTM:Crabs I- Emerald crabs

[pyro]

I have had 2 of these in the past. They were great to watch and very interesting. Sadly, both turned white over teh course of about 2-3 months and died soon after. The second one didn't count though, it came with only 3 legs an one pincer, lasted a good 3 months though surprisingly.
Any reasoning this could be? All my reef levels are normal.
Certainly took care of the bubble algae though =)

 

[rcbruce]

this really helps. I have a SEVERE bubble alge problem and thought I had to live with it. Kinda worries me about the fish, but I don't see where anyone says they have actually lost a fish to an emerald?

 

[wax32]

They are 99.999% herbivorous. If they eat a fish it was most likely dead already. And even then it might not bother it. My emerald didn't even notice a dead clam in my tank. All it does is eat algae.

 

[jerthunter]

I finally got myself an emerald crab, I used to think that they were ugly things from all the pictures I had seen but after seeing several ones in person and hearing about their algae eating potential I had to get one. When I first got him he mostly just hung out in one place, hiding behind a rock durning the day and exploring the front of the rock at night. He never seemed to do much eating though and I started to notice he was scratching and picking at his exoskeleton. I assumed he was getting ready to molt and several day ago I no longer could find him, even at night, then a day or so later I located his molt. It has been three days since I noticed his molt and I still cannot for the life of me find the little guy. I am just curious, does anyone have any ideas of how long they normally hide after a molt before coming back out? Also, after hearing about how great they are at eatting algae I am a bit concerned since my crab never seemed to be going for any of the algae in my tank that I have noticed. Just for reference how long would it probably take a single emerald crab to clear a 4 inch by 4 inch patch of green algae from a rock?
I guess that is all for me.. Hopefully he will reappear soon in a shiny new exoskeleton so I can get a nice picture..

 

[celacanthr]

My last emerald crab disappeared after molting, and I never saw her again.

As for the time it takes to clear a 4"x4" patch, I suppose it would depend on several things:

• availability of other 'tastier' algaes
• tankmates
• Temp (will change how quickly they move, and how often they need to eat)
  Stress
  How long since their last good meal

 

[jerthunter]

I figured it would depend on alot of things but I am just worried since I have heard they are great algae eaters and I haven't noticed mine eatting even with algae present for about 2 weeks.

 

[fisherson]

I've had a fw emerald crabs over the past 2 years just recently got 2 more. Can anyone tell me why mine always turn white?

 

[celacanthr]

I have heard that them turning white is a sign of an impending molt, but I am not sure if that is necessarily true.

 

[saltn00b]

well here is my em pics.
i have seen 1-2 of my larger ems munching on what looked like my zoo's of one particular coloration. but then upon closer inspection it seemed that when the polyps were closed up, he was pulling the algae off of the rock the collected imbetween and under the polyps.
he left and the next day all the polyps were there and unharmed. :jumping: