Emerald crab predator?

Phlipper

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Hey my emerald crab has started killing my snails. Will this behaviour continue do you think? I didn’t put any food in the tank yesterday because I worked a 36..... I’m wondering if I should keep him or not.
 

GatorScott

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Just try to keep him full. But ya he’ll prob continue to kill snails now that he’s got their taste.
 

Ike

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What kind of snail? My experience with emeralds is that they don't bother snails unless they're able to scavenge them.
 

Jettareefer223

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I’ve had them chew on my stylo’s and pocci’s pick the polyps straight off one buy one. Literally witnessed happen for days and if I moved far away they with speed make their way back. I know it’s not snails, but I’ve experienced weird behavior I removed them and no longer own emeralds carbs.
 

Ike

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I’ve had them chew on my stylo’s and pocci’s pick the polyps straight off one buy one. Literally witnessed happen for days and if I moved far away they with speed make their way back. I know it’s not snails, but I’ve experienced weird behavior I removed them and no longer own emeralds carbs.

Yep, they'll pick at certain corals for sure. They like algae, and other than that they're opportunists and will scavenge or eat whatever is fed. All that said, I've never seen them take down a healthy snail, nor can they catch and kill a healthy fish like so many have claimed. Mine cant even take down a piece of flake food out of the water column with their claws.
 
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Jettareefer223

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Yep, they'll pick at certain corals for sure. They like algae, and other than that they're opportunists and will scavenge or eat whatever is fed. All that said, I've never seen them take down a healthy snail, nor can they catch and healthy fish and kill them like so many have claimed. Mine cant even take down a piece of flake food out of the water column with their claws.
Yeah I would tend to agree with you the snail would have to be dying or upside down. Once food rains from the sky they get lazy lol.
 
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Da8

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In hunger they eat whatever they can...
At long term, they are difficult to keep in tanks where there is little food available and no algae to feed on because they usually take it on corals... Specially the ones you like the most
 

Cell

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Feed your emerald crab nori.
 

Jay Z

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Ive seen my hermits go after snails before, not sure if they want the shell or are trying to eat them.

I have 12 emeralds split between 3 tanks. 4 in my 6 gallon. So far they've been perfect angels over the last 8 months.

The only aggression I've seen is one in my 14, he tries beating up my 12" carpet anemone. Fun to watch at night. That one is stubborn as all get up trying to get that algae behind the carpet lol
 

jaxredsoxfan

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Feed your emerald crab nori.

Second that, mine loves Nori
1566041010775.png
 

AdamNC

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Feed them nori or sinking algae waffers. Since I have very little to no algae in my tank I feed 4 waffers a week to all my cuc. If you use tongs they are less likely to run from you and once they get accustomed to the tongs and see the waffers they will come running out of the rock work.
 
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Phlipper

Phlipper

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What kind of snail? My experience with emeralds is that they don't bother snails unless they're able to scavenge them.
It was a trochus a fairly big one too. Always stayed on top of my rock work
 

Deiblerj

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That’s the tough balance between snails and crabs. I’m always having to toss a few new snails in my tank because the crabs eventually get to them
 

Ike

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Ive seen my hermits go after snails before, not sure if they want the shell or are trying to eat them.

I have 12 emeralds split between 3 tanks. 4 in my 6 gallon. So far they've been perfect angels over the last 8 months.

The only aggression I've seen is one in my 14, he tries beating up my 12" carpet anemone. Fun to watch at night. That one is stubborn as all get up trying to get that algae behind the carpet lol

Certain types. However, I've never seen a red leg bother a healthy snail. They do not kill snails to get their shells. You can confirm this if you examine their shells when they're collected. Blue legs can be punks, and I find emerald crabs to be algae eaters, but they will all scavenge just about anything.
 

Ike

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It was a trochus a fairly big one too. Always stayed on top of my rock work

It was likely on it's way out or died for one reason or another. I don't think an emerald crab could take down a large and healthy trochus if it wanted to.
 

rkpetersen

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I would never trust emeralds any more.
I've seen them pick at various corals.
While doing very little to control algae.
 

Jettareefer223

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It was a trochus a fairly big one too. Always stayed on top of my rock work
On another note after 20 years I’ve always kept a fair amount of snails 2 or 3 per gallon . Trochus are the best and eat everything I stick with blackfooted they will eat cyano, diatoms,and pretty anything that qualifies as algae and last for a fair amount of time. Astrea’s last awhile they just don’t have the same vigor and activity levels. Occasionally I have to flip them over they usually right themselves doing wiggle dance. Unless the emerald is huge and I don’t think it would have the strength to peel it’s foot enough and even if I could I don’t think possesses the capability of holding on to a healthy flailing trochus or the speed to excute such a task. Like I said earlier unless the snail is fatigued from being upside down an extented amount of time it’s a done deal. I have several service tank’s that house multiple emeralds and lots of trochus which have been in the tank together for over a year and half. I haven’t personally experienced anything to that nature.
 
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FragileReefer

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My emerald crab was the best cleanup crew member I ever had. Hair algae, bubble algae, he was amazing. Till he got hungry. He started with a few zoa polyps. But he got evicted when I saw him pulling a rock flower nem off the rocks.

I have been struggling with GHA since then, but emerald crabs can turn on you quick. Bless all you that don't own pychopaths.
 

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