porcelain crabs are aggressive

[javisaman]

I finally found the culprit to my missing crab problem and random nippings to my mandarins. Both my clownfish and porcelain crab snip/nip at my mandarins occasionally cutting their tails, never any real damage though usually recover the tail in a few days. The crab however does kill everything that looks remotely like it, i.e. emerald crabs and pom-pom crabs. I don't know if anyone else has experience with porcelain crabs being so aggressive, but i thought i should share.

Edited November 1, 2011 by javisaman

[Dani3d]

not a chance. My porcelaine crab just plain stay in its maxi mini anemone and just filter water. I never saw it nip at anything, but you say your mandarins...you have more than one? if that so, it could be them fighting?

 

My crab is the white small procelaine and it is harmless. My emerald is about 3 times its size and build like a tank, so I really doubt it could kill it, even if it wanted to do so.

 

I finally found the culprit to my missing crab problem and random nippings to my mandarins. Both my clownfish and porcelain crab snip/nip at my mandarins occasionally cutting their tails, never any real damage though usually recover the tail in a few days. The crab however does kill everything that looks remotely like it, i.e. emerald crabs and pom-pom crabs. I don't know if anyone else has experience with porcelain crabs being so aggressive, but i thought i should share.

[Arkayology]

Mine sit in my encrusting gorg or zoas and filter feed. I have never seen it raise its claws at anything accept pellets or mysis I drop in. Maybe you have a weird one or a species that is aggressive?

[ry05coupe]

Porcelain crabs (http://www.liveaquaria.com/product/prod_display.cfm?c=497+501+1963&pcatid=1963) and Porcelain Anemone Crabs (http://www.liveaquaria.com/product/prod_display.cfm?c=497+501+629&pcatid=629) definitely hve diffrent behavior traits.

Edited November 1, 2011 by ry05coupe

[Deleted User 6]

Does it get enough to eat? Porcs are filter feeders and often starve without appropriate food sources. They're actually in the lobster family, and like all members of that family they are opportunistic feeders. If it's starving and thinks it could snag a fish, I wouldn't put it past it to try.

[javisaman]

Mine is a white one. I feed it as much as i feed the fish. I wouldn't say aggressive as much as territorial. Mine doesn't move either. It's when other crabs/fish get near it that it gets nippy. All of the pom-pom/emerald crabs are about 1/2 its size. Usually it doesn't eat them, just leaves the body near its area. The crabs usually have arms/legs off and are upside down. I thought it was something else, but they all died within inches of where it stays. It maybe because they somewhat resemble conspecifics.

Edited November 1, 2011 by javisaman

[altolamprologus]

I have a porcelain crab(generally more agressive than porcelain anemone crabs) and it never bothers my pom poms or fish (including the mandarins). I have heard that they may kill other crabs in small aquaria, but it's usually only if they aren't fed enough because other crabs are competition for food. You say you feed it as much as you feed the fish, but what are you feeding it? It may not be eating what you give it.

[javisaman]

I spot feed the porcelain pe mysis, brine, nutramar ova, blood worms, whatever is on the menu for that day using the same tool for feeding mandarins. I feed nearly everyday (depending on algae buildup) since i have two mandarins that need constant feeding.

 

from an old thread of mine

 

 

I originally suspected emerald crabs, but they're all dead...and it still happens from time to time.

[altolamprologus]

I spot feed the porcelain pe mysis, brine, nutramar ova, blood worms, whatever is on the menu for that day using the same tool for feeding mandarins. I feed nearly everyday (depending on algae buildup) since i have two mandarins that need constant feeding.

Can you confirm that he is indeed eating the food and not just letting it float past him? You may have just gotten an evil crab though...

[Jtotheb]

I have three blues in a bc29. The only time they are aggressive to each other or anything else is when something gets in the wake of its fans. And even then its more they wave their arms and claws around, nothing serious or latching on. I did alot of research on them before I got them 6 months ago. Never came across anything or anybody having overt aggression or killing things with them. Mine hang out together ( at a small distance from each other) and have been nothing but a treat in my tank that includes 5 fish and tons of coral all over the place.

 

Have you actually seen it kill a crab in your tank? Not just a little pushing around?

 

Are you sure you have a positive id on the crab you have?

[javisaman]

Can you confirm that he is indeed eating the food and not just letting it float past him? You may have just gotten an evil crab though...

 

 

Definitely eating. Especially things he can grab. Usually just fans in stuff like nutramar ova.

 

 

I'll post a picture soon, but definitely a porcelain anemone crab. I will admit I've never seen it kill anything, but it seems more than just a coincidence that the crabs die near it (they aren't just molts).

[castiel]

I have seen mine take a swipe at a shrimp that got too close ... think it might even have nipped off one of its antennae. But the shrimp/YCGs seemed to quickly learn to stay out of its space, so no trouble since.

[altolamprologus]

Definitely eating. Especially things he can grab. Usually just fans in stuff like nutramar ova.

 

 

I'll post a picture soon, but definitely a porcelain anemone crab. I will admit I've never seen it kill anything, but it seems more than just a coincidence that the crabs die near it (they aren't just molts).

Then your crab is probably just a d!ck.

[mndfreeze]

My white anemone hosting porcelains never caused problems. My blue/green ones that do not host seemed to get territorial.

[hexbasher]

(crappy pic via flashlight and iphone)

 

this clown only hosted at night, but the crab allowed it...i also have emerald and pom-poms in the tank....the clown on the other hand is territorial of other fish but thats typical

Edited November 3, 2011 by hexbasher

[Seadragon]

On 11/1/2011 at 3:33 PM, Jtotheb said:

I have three blues in a bc29. The only time they are aggressive to each other or anything else is when something gets in the wake of its fans. And even then its more they wave their arms and claws around, nothing serious or latching on. I did alot of research on them before I got them 6 months ago. Never came across anything or anybody having overt aggression or killing things with them. Mine hang out together ( at a small distance from each other) and have been nothing but a treat in my tank that includes 5 fish and tons of coral all over the place.

 

I'm thinking of buying 3-6 Purple Porcelain Crabs (Petrolisthes sp.).  These are known to be very shy and hide under rocks and such, they look like this:

 

I used to own 2 Spotted Anemone Crabs (Neopetrolisthes ohshimai).  They prefer to live on anemones and can clean the host anemone by eating the food scraps and mucus off the anemone’s body surface.  One of mine got aggressive with the other one and I unfortunately didn't have any anemones for them to live on.  They look like this:

 

Has anyone owned the Purple Porcelain Crabs (Petrolisthes sp.) and what was your experience?  I heard somewhere that the "blue" porcelain crabs can be hard to keep alive?  Also, I heard that they are indeed very shy and you may never see them (which is why I'm contemplating getting like 6 to guarantee I'll see at least one).  Thoughts?