Blue Lobster in a Community Tank

[Bluestman]

Hello everyone, over the last 6 months or so I've been trying to find as much info as I could about Blue Lobsters (Cherax quadricarinatus) as I bought my tank with the intention of buying one. I have read quite a few articles saying that they are not suitable for a community tank because they will eat fish but I have read just as many articles saying they are OK. Then there are the fencesitters who say it depends on the lobsters personality, some are good and some are bad. As there is relatively little information around, I decided to try and log my experiences and a little to the knowledge base. I hope that doesn't sound conceited.

I have deliberately picked fish that are quick off the mark as most of the information I have read says that lobsters can only catch quite slow moving prey. Again this is contradicted in other articles. Most of the information I have read suggests feeding them live fish occasionally. It's not something I wish to do willingly but if he catches one of the Danios or a Molly then at least he is getting his dietary requirements. I am not too attached to any of the fish as I am aware that at some point they maybe become lunch for the lobster. It is also stated in a lot of articles that the lobster will decimate any plants that are in the aquarium so I have bought a shedload of Java Fern which will hopefully grow quicker than it gets eaten.

I must at this point let everyone know that I am by no means an experienced aquarist. The only relevant experience I have is with regards to reptiles which I have kept for around 10 years. A lot of the skills from that hobby transfer quite well into aquaria. I have had my tank up and running for 7 months and have yet to have a fish die. All my levels are spot on and all the fish and plants are apparently healthy.

I ordered my lobster online and it arrived boxed yesterday. It is around 3 1/2 inches long and isn't actually blue rather a green/brown colour. As it ages it will turn blue apparently.

So after 3 hours of drip acclimatisation I added my lobster yesterday. remembering to put him into the tank upside down to release any air that gets trapped under his shell. I spent the next couple of hours watching for signs of aggression towards his tankmates, there was none. The mollies showed him a lot of interest and seemed to annoy him but that was about it. He did a tour of the tank and decided to settle right under the filter next to a cave (one of four) that I had provided for him. He spent a few hours last night moving stones around, as if he was constructing a wall to block himself in.
The next day it seemed he had disappeared, I just left him to it then in late afternoon I saw what looked like a dead lobster. He had moulted and was busy eating his old shell. They are particularly vulnerable whilst their new shell is soft so that is probably why he was constructing the "wall" the previous evening.
So far the only sign of aggression I have seen is when a fish goes near the shrimp pellet in his cave he scares them away by waving his claws around. The biggest problem so far has been the Apple Snail. It doesn't scare away easily and was trying to eat the lobster's old shell. Lobster threw a tantrum and the snail retreated at warp speed (for a snail that is anyway lol).
Well that's all there is to say so far, as and when anything of interest occurs I will endeavour to update this post. If anyone has anything to add then please do so.

Clive

 

[Zagz]

Interesting. Any pictures of the tank?

 

[GhostKnife]

Not trying to scare you but the only things Ive heard about the electric blue lobster is that you should not house it with fish. More so fish that are smaller than the lobster when full grown. But very cool findings and observations. The lobster is sweet looking however.!!

 

[Bluestman]

@ Zagz I will get some photos up as soon as possible. At the moment he is still eating his shell which is necessary in order for him to reclaim the cacium. Failure to do so is apparently fatal in 80% of cases. I assume that when he has finished that and when the hardening of his new shell is complete his behaviour will change. Chances are that because he has just eaten his shell he won't feed for the next 48 hours or so. He is very shy at the moment because he is vulnerable and I don't really want to mess him around too much at the moment. As soon as he starts running around the tank I'll try to get some shots .
I am trying to keep out of the tank for a few days to let him settle in. I am doing a 15% water change/gravel clean daily for the first week he is in there and then slowly reducing that to once a week with gravel cleaning every 3 days or when needed.

@ Ghostknife, I fully expect him to at least attempt to eat some of the fish. That's why I went for cheap and cheerful swift moving fish. The Danios seem to know he could be a threat. Before he entered the tank they all used to "sleep" near the filter. Since he has been living underneath it they have moved to the other end of the tank. When active however they will quite happily swim just out of reach of his pincers. The mollys occasionally get a bit too inquisitive and he warns them off. They are slightly bigger than him at the moment so I guess that's why they are braver than the Danios.

So far the only aggression I have seen is when he is protecting his food or when fish come too close. It is very early days yet but if he continues to show no predatory interest in the fish I plan to add some Tetras to add a bit of colour to the tank. I'll see what happens over the next couple of months.

By the way, how many people are waiting for the "My Lobster ate all my fish" post. I know I would be if I was reading this lol.

I do need to get an algae eater of some sort, can anyone think of an algae eater without much in the way of fins that can quickly and avoids lying on the bottom of the tank for extended periods? Golden Algae Eater maybe?

Clive

 

[new2betas]

Looking forward to pictures....

 

[Bluestman]

I just caught him out of his cave. He emerged when I fed the other fish which I didn't expect. This is the best photo I could get, is there some kind of trick to getting decent pictures of the inside of the aquarium? As you can see he's not blue at all yet but as he gets older he will change colour.

and another from just now when he came out for a bloodworm pellet. He doesn't appear to be hungry though as he is just stashing what he can pick up in his "den".

Clive

 

[new2betas]

How cute!! Keep the pictures coming...especially when he turns blue!!

 

[jsoong]

Looks really cute! Keep up the observation & posts....

I don't think any algae eating fish is truly safe from the lobster. Plecos & otos will be too slow. The CAE (the golden is a varient) will not eat algae & will more likely eat your fish when grown. SAE might be fast enough, but they have weak swimbladder & spend a lot of time sitting so will be susceptible to a sustained hunt.

The best I think would be nerite snails although they are hard to find.

 

[RogerMcAllen]

I think you are kidding yourself if you think that there are fish that aren't too slow for or are too big for the lobster. Remember, the fish are sleeping when the lobster is most active. Keeping fish with lobsters is a recipe for disaster regardless of the size/speed.

 

[TheNamelessPoet]

wow that 2nd pic is AWESOME!!!

 

[miniflea84]

Please, by all means keep us updated with pics and info.

 

[Bluestman]

I think you are kidding yourself if you think that there are fish that aren't too slow for or are too big for the lobster. Remember, the fish are sleeping when the lobster is most active. Keeping fish with lobsters is a recipe for disaster regardless of the size/speed.

As I have stated in my first post, I am fully prepared for the loss of some if not all of my fish. I have bought what I thought were the fish most likely not to be eaten to see if it will work. If I end up with no fish then that's not really a problem. They cost less than £20 and I bought and set up the tank specifically for the Blue Lobster anyway. The way I see it there is no real difference between doing this and feeding Oscars feeder fish. Or feeding a cricket to a gecko.


Behaviour wise he is a lot more active now he has eaten his old shell. I planted some Java moss yesterday evening which he duly came out to inspect and nibble at when I had left the tank alone. He then covered the whole floor of the tank clearing up left over food. It's quite hypnotic watching how he does this, it is a blur of movement as he uses hisPereiopods (walking legs) to investigate every nook and cranny in the gravel and shuffling what he finds forwards to his mouth. When he isn't feeding he tends to sit at the front of his now, almost fully built "den", with just his head and front pincers sticking out. As if he is keeping guard.
There have still been no signs of predatory aggression from him, even when a Danio swam directly in front of him for 5 minutes or so he just ignored it. He seems genuinely nervous when the mollys are around him though I guess as he gets bigger that will stop. When they get too close he retreats fully into his den.

Clive

 

[fearlessfisch]

This is a great thread. I love the descriptions of his life. Please keep writing!

 

[Dan Seact]

Awesome thread, ive enjoyed reading it so far!
Ive heard of feeding them egg shells, for cacilum.
I was going to get one of these but then I fell in love with the German Blue Rams
Cant wait to read on!

 

[Terry]

As your lobster grows he will slowly empty your Aquarium of all the other occupants. The quicker he eats them the faster he will grow.

 

[gzeiger]

I've found with other species of crayfish that they grow faster and shed more often if provided with a regular calcium source (no surprise there). An easy maintenance-free way to do it is to add some crushed coral to the bottom of the tank, which will slowly dissolve into the water over a very long period of time.

 

[fishfreak5]

a spotted plecostamas can grow up to twelve inches how big does the lobster get?

 

[gzeiger]

It's not really a lobster, it's a standard crawfish with unusual pigmentation. It will get about 4 inches long. I've seen a couple in the wild bigger than that, but not by much.

 

[GIES2525]

Awesome Thread. I too have a Blue Lobster in with my community fish, and he is as BIG and Blue as they get. I bought a mature one about two months ago, and he does have some agression. I have lost one Ballon Mollie because of him, but i didnt lose sleep over it. I have a full grown Angelfish, with beutiful fins. And he cant touch her. Mind you i do have a 39 gallon tall tank, but he cant catch the angel. He walks around and trys to get any fish he can get his pinchers on. Fortunatly he cant catch them, and they seem to get a kick out of sitting and waiting for him to get right next to them, and then they scurry away. I also, have quite a few hiding places for the fish. Good Luck, Im in the same boat you are, because i to was very curious about these creatures... And they are SWEET!!!

 

[GIES2525]

Sorry for the double post, but i might have an idea for your bottom feeder. Im not sure if they are considered a bottom feeder or not, but my Red finned shark goes around eating stuff off the bottom, and on all my decorations. And the Blue Lobster dont want anything to do with him. But i did get the Red finned shark first, so he had his area already marked, before the lobster was put in. But the Lobster runs when the shark swims around him. And the Shark is Beutiful looking, with a bright red back fin, and an all black body.