Need help identifying shrimp

[SD21]

Hello, I've had this shrimp in my tank for quite a while now without ever really knowing what species it is. Im going to get some red cherry shrimp for my tank now however the one I have is very aggressive so I need to remove it.

The assistant at the shop said it would be fine to keep with some smaller fish but it has actually killed a few! It was sold to me as freshwater shrimp or something like that. Im just curious to know what kind of shrimp it is though, I dont think its a ghost shrimp it looks like a red claw shrimp but it doesnt have red claws so I dont know! Any help would be great.

[demonte1997]

That is a freshwater prawn (macrobrachium) of some sort. I want to lean toward it being M. amazonicum but hard to say until it grows more. They are very aggressive and not kind to fish, shrimp or even their own species. I would not try to add any other inhabitants to that tank. Case in point, I added an amazonicum to a cherry shrimp tank (had no where else to put it). Cherry shrimp population went from 100+ to about 5. Took the amazonicum out and now there are over 200 cherries in there. I think you can see where I'm going with this. They like to eat and destroy things.

If you have a tank that you can dedicate for it, it will likely be a very rewarding pet. Prawn are an intriguing species in the freshwater hobby that gets very little recognition. I liken their personality to that of a cichlid. Most often they will sit in the front of the tank waiting for you to walk by and they will "beg" for food. You can train them to eat out of your hand (if you're daring enough). Males of this species can get quite large (some around 12" body alone). They grow quickly and the shapes/sizes of their claws change/grow dramatically with each shed.

How big is it now? Where did you get it (store, what region of US do you live)?

edit: vid of my blue prawn. http://www.youtube.com/watch?v=_VbFd39htmg

^ just a baby but you can see the appetite

Admin Edit: Fixed the non-functional link. Working now.

[SD21]

Thanks for the reply, yeah I definitely wont be adding anything else to the tank! But I would love to keep it, it is very interesting to watch but unfortunately I dont have another tank so I will have to decide. I have another in there as well which is alot smaller im guessing its possibly a female it has not really grown at all. The the one in the pictures is growing very quickly its nearly 3 inches now, and 12" you say how long would that take? Ive had it around about year now.

Im actually from the UK by the way, and your video doesn't seem to work!

[demonte1997]

It's tough to say how big your prawn would get without knowing what species it is. If you've had it for about a year now and it's only 3", that's likely its max size. Amazon prawn, M. amazonicum get around 6" max size from what I've seen. It's tough to say what species prawn you have since you are in the UK. I'm not certain what species are sent up that way.

I apologize for the vid link not working. Give this one a shot:

http://www.youtube.com/watch?v=_VbFd39htmg

[demonte1997]

After looking at your prawn's rostrum further, I want to lean away from it being an amazonicum. From what I've seen, their rostrum is usually a little more elongate. Sorry, this doesn't really help you as I haven't been able to provide a positive ID.

[SD21]

No problem thanks for the help anyway, ive just realised looking at it today its carrying alot of eggs around, I can safely say I dont want more of these prawn in my tank!

Vids working now it looks very cool I like those blue claws.

[demonte1997]

If there is a female that is holding eggs, I would be curious to see how big the eggs are. If large, there is a chance that your prawn are a smaller species that reproduces entirely in freshwater. I know you said you don't want any more (understandably so) but being able to breed them is truly a rewarding experience.