Fish eating emerald crab!!!!!!!!!!!

harris28

harris28

Member
Okay, I had an algae problem and I narrowed it down to my lights. I had turned the lights off in the tank for 3 days and when I turned them on there were 3 things missing. Algae, gold stripe maroon, and a blue hippo tang.
Are you telling me that a emerald crab killed and ate my 2 inch GSM and my 5 inch blue hippo? How can that be??? Oh I am so mad!!! At least my fox face made the terror!!!!
Has anybody ever heard of this??? OH I AM MAD RIGHT NOW!!! Thinking about tearing my tank down to get the crab and step on him!!!!!!!!!!!!
 
perfectdark

perfectdark

Active Member
Crabs are opportunistic omnivours, they will capitalize on a sick or ailing fish. However, I highly doubt it caught a perfectly healthy GSM and or Hippo Tang. Unless the emerald itself was very large... say over 3"+ JMO
 
harris28

harris28

Member
Originally Posted by PerfectDark
http:///forum/post/2817964
Crabs are opportunistic omnivours, they will capitalize on a sick or ailing fish. However, I highly doubt it caught a perfectly healthy GSM and or Hippo Tang. Unless the emerald itself was very large... say over 3"+ JMO
The crab was no that big at all but also the fish appeared to be healthy. Just the other day I did a water sample and all parameters were in check. I know that really does not mean much as far as fish health but even when the lights where off I would see them swiming around. I had them both for about a year with no problems. Actually the tang looked really good, the best I have ever kept. Most of my tangs get HLLE but not his one. I stayed on it!! Oh well, I still have one fish left and a whole bunch of corals.
 
unleashed

unleashed

Active Member
here's an odd question do you happen to have a brittle star? if so how big.. now yes emeralds will eat smaller fish or if they have died leaving no evidence of them at all.. however a large brittle will attack fish hiding in there territory..what type of fish do you keep.. from what you are describing lights being off for three days your fish went into night mode...hence hiding in the rocks.. something in your rocks took them out
 
harris28

harris28

Member
Originally Posted by unleashed
http:///forum/post/2818035
here's an odd question do you happen to have a brittle star? if so how big.. now yes emeralds will eat smaller fish or if they have died leaving no evidence of them at all.. however a large brittle will attack fish hiding in there territory..what type of fish do you keep.. from what you are describing lights being off for three days your fish went into night mode...hence hiding in the rocks.. something in your rocks took them out
Nope, no brittle star. Just my emerald with hermits and snails. Only fish I have/had were the two that died and the fox face. I actually just found the emerald eating on the tang and found the GSM next to it. So my Ammonia spiked to .25 and do you think I have any water made?? Of course not. And since I work midnight shift, I should already be in bed. I removed the two dead fish and my lights are back on. I have no choice but to call it a night not knowing what really happened.
Is ammonia more toxic with high or low Ph? My PH seems low too! Man it was just fine 2 days ago. This is all strange.
 
unleashed

unleashed

Active Member
Originally Posted by Harris28
http:///forum/post/2818117
Nope, no brittle star. Just my emerald with hermits and snails. Only fish I have/had were the two that died and the fox face. I actually just found the emerald eating on the tang and found the GSM next to it. So my Ammonia spiked to .25 and do you think I have any water made?? Of course not. And since I work midnight shift, I should already be in bed. I removed the two dead fish and my lights are back on. I have no choice but to call it a night not knowing what really happened.
Is ammonia more toxic with high or low Ph? My PH seems low too! Man it was just fine 2 days ago. This is all strange.
ph is a bigger factor when it comes to fish health both are important factors however .25 is not normally detrimental for short term exposure.. ph does lower when subject to lack of light..this is what I have heard at least.. how low was the ph?this could have been the fish issue all along
 
harris28

harris28

Member
Originally Posted by unleashed
http:///forum/post/2818180
ph is a bigger factor when it comes to fish health both are important factors however .25 is not normally detrimental for short term exposure.. ph does lower when subject to lack of light..this is what I have heard at least.. how low was the ph?this could have been the fish issue all along
Today it was 7.5ish not too low at all but 3 days ago it was 8.2. See I had a bout of cloudy water this week with zoas melting away while LPS,SPS, clam, rics, and shrooms were all fine. The only thing I did was a water change and I've had everything over a year so it could not have been a lack of maturity. So because of that I checked all parameters which was ph:8.2 amonia, trite, trate 0, cal 420, alk was 2.5 salinity 1.206, temp, 78 and mag 1320.
So at that point I figured the cloudy water was due to algae because it had floating matter in it and I started getting this brown velvet algae covering the rocks. So that is when I decided to turn lights off for a few day, and today the horror.
So that was about a weeks worth of info that I had and the only thing I came up with was that the emerald crab was hungry when they went for sleep. But I don't understand why it would have killed both fish when one would have clearly been enough. Oh well I cant bring them back and I'v done all I can tonight. I will check ammonia when I get off of work in the morning and hopefully it will have went down and nothing else kick the bucket.
just realized i'm in the fish only thread
Oh well stressful day!!
 
ilovemytank

ilovemytank

Member
I second the opinion that there is no way an emerald crab caught and ate both your fish. He may have eaten them if they were sick or already dying. Imean, yes they are oportunistic feeder ( although they prefer algea and will hunt when hungry ) but for an emerald crab to bring down a 5" tang even if he got a great jump on him.......Maybe possible but doudt it. Now lets address the issue of eating him, How long does anyone out there think it would take a emerald crab that is under 3" to eat a 5" blue tang ? Even if your lights off the crab you mentioned you saw the fish swimming. How long did you miss them before you realized they were gone ? The crab isn't one that will eat itself to death and would take days to eat a fish that size. Even with the help of hermits. Then you factor in that he had to eat another 3" fish as well in that time period. I don't think your crab is the culprit. could your fish have jumped out of the tank and be behind your tank on the floor ? I once had a freshwater tank that my purple crayfish got out I searched for days for him. About a month later I was moving and took apart my bed in the next room over and found his dried out corpse under my bed. That was a long crawl or cat snack.
 
harris28

harris28

Member
Originally Posted by Ilovemytank
http:///forum/post/2818569
I second the opinion that there is no way an emerald crab caught and ate both your fish. He may have eaten them if they were sick or already dying. Imean, yes they are oportunistic feeder ( although they prefer algea and will hunt when hungry ) but for an emerald crab to bring down a 5" tang even if he got a great jump on him.......Maybe possible but doudt it. Now lets address the issue of eating him, How long does anyone out there think it would take a emerald crab that is under 3" to eat a 5" blue tang ? Even if your lights off the crab you mentioned you saw the fish swimming. How long did you miss them before you realized they were gone ? The crab isn't one that will eat itself to death and would take days to eat a fish that size. Even with the help of hermits. Then you factor in that he had to eat another 3" fish as well in that time period. I don't think your crab is the culprit. could your fish have jumped out of the tank and be behind your tank on the floor ? I once had a freshwater tank that my purple crayfish got out I searched for days for him. About a month later I was moving and took apart my bed in the next room over and found his dried out corpse under my bed. That was a long crawl or cat snack.
Well I can't explain this whole thing at all, because prior to turning off my lights for 3 days the fish were all healthy, happy, swimming, and eating like pigs. So as to what happened I can't tell you anything other than they are dead
.
But I did find both fish tucked under a rock. With the ammonia spike, I had to find them before my corals started to go. I found the emerald was eating my tang and my GSM had already been snacked on but neither to the point of them being unrecognizable.
I am wondering if the prolonged lights out, cause the PH to stay low for an extended period of time and caused the fish to get lethargic resulting in getting fatally clawed by the crab. That is what I am going with and I will never turn my lights off for that long ever again.
 
knockout

knockout

Member
"alk was 2.5 salinity 1.206"
are these readings correct? if so then your salinity is probably the killer here, that is WAY TOO HIGH, normal salinity should be around 1.024, but I am leaning to a typo, your alk is also very very low
I also don't think the crab could have killed either fish even if they were lethargic which I dont think a lights out of 3 days would enduce, fish dont depend on lights for feeding. When a fish dies it becomes fair game to the rest of the inhabitants, other fish, snails, hermits (my kids call them "the savages" as they devour anything dead in minutes)
 
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