Petshrimp.com Discussion Forum

I picked this guy (is it a male? I'm having difficulty finding diagrams or reference photos of how to tell) up from a friend, and I have no idea what he is or what his potential size is likely to be. Currently he would be about 14-16cm excluding his nippers.

I originally thought perhaps he was a cherabin (M. rosenbergii) however after looking at more photos that doesn't seem likely given the colouration of his nippers. Though, looking through even more pictures, I'm at a loss as to what he might be otherwise. The lower part being that lighter cream colour does seem to match with some pictures, but the lack of blue coverage is a bit less promising. How much colour variation does this species show?

Any help would be appreciated, even if it is just a shove to more labelled pictures (I've gone through all at wirbellose already). The most I know for sure is that it is native or endemic to Australia.

(please excuse the rather overstated decor, it was a bit last minute)




Thanks guys, I appreciate it.


(and if you are feeling like a challenge, any idea what this one is? Pretty expensive little critters, about 9-12cm long, most likely Aus natives. I didn't buy these ones, but am thinking I may if I find them again, if I can figure out their requirements - I only have the tankspace for one massive shrimp
http://img.photobucket.com/albums/v314/ ... townPP.jpg)

As to yours, my first inclination was a female M rosenbergii. Badflash used to breed that species, so he should be able to tell you definitively if it is or not. It is my understanding that the females dong get the same coloration as the males.

I could easily be wrong though. The only M. species that I currently have are M. dayanum (Red Claw shrimp), or possibly some unknown Hendersoni species.

FYI, females have a thicker tail and their carapace extends down farther past their swimmerets so they can easily carry eggs.

I really like the yellow Macros in your link. Depending on how aggressive they are, I'd love to breed them in my tanks too!

Looks like a young orange claw male, but it could still be a female. Definely M. Rosenbergii. Until they are fully adult and either get eggs, or huge blue arms, it is really hard to tell the sex.

Either way, they are very smart, and very agressive. Apple snails are good tank mates, but they eat just about everything else.

I kept endler's live bearers with them. Those can breed faster than they can be eaten.

Wonderful, thanks guys!

When you say orange claw, is that a random colour variation or a particular strain?

He is pretty clever, now that you mention it. I have caught him watching me a few times as I walk about, that just isn't right! He'd sussed out the tank and feeding routine within a day, checked for escape routes, looked for prey, and had a very purposeful push and shove of all the objects in the tank. I think I might need to rotate toys!

I might give the endlers a miss, they only became available here last year and are still stupidly expensive, but I think he'd like the challenge of mozzie fish and firetails as both are rather bent on survival.

For what it's worth...I agree that it's a M. rosenbergii.

Its worth a lot! I finally got one right!

Callatya wrote:Wonderful, thanks guys!

When you say orange claw, is that a random colour variation or a particular strain?

He is pretty clever, now that you mention it. I have caught him watching me a few times as I walk about, that just isn't right! He'd sussed out the tank and feeding routine within a day, checked for escape routes, looked for prey, and had a very purposeful push and shove of all the objects in the tank. I think I might need to rotate toys!

I might give the endlers a miss, they only became available here last year and are still stupidly expensive, but I think he'd like the challenge of mozzie fish and firetails as both are rather bent on survival.

They can easily be trained to take treats outof your hand.

There are actually 3 types of males in the same species. The Blue claw is the dominant male. He will kill any other blue claws in the tank. The orange claw is a sub-dominant male and has no interest in mating. he is tolerated by the blue claw. There is also a runt, that looks for all the world like a juvenile female. He will mate, given the chance, but the females don't find him very attractive. Most of the girls will hang out with the big blue.

Feeder guppies are probably a good choice for mates/food. They will clean up left overs and multiply like crazy. Most any fish will fall prey to these guys, so don't spend any money on tank mates.

Hi folks!

Mustafa wrote:For what it's worth...I agree that it's a M. rosenbergii.

Full agreement, Mustafa!
The prawn on the pic of Callatya is a TRUE M. rosenbergii. Unlike most other photos you can find in the web (also the left two specimen in our gallery: http://www.crusta10.de/templates/index. ... 54&katid=2 are still incorrect labeled, the female specimen at the 2 right pics instead are true M. rosenbergii).

This was clarified in a revision of the M. rosenbergii complex, published 2 weeks ago in the Raffles Bulletin of Zoology by Daisy Wowor and Peter Ng: http://rmbr.nus.edu.sg/rbz/biblio/55/55rbz321-336.pdf

By this, your Australian specimen (like the female from Sulawesi on my pic below) belong to M. rosenbergii sensu strictu. Most other specimen (like those badflash showed here in this forum and almost all from aquaculture ponds) in fact belong to Macrobrachium dacqueti instead!

Because this would cause many confusions the taxonomists will contact the International Commission for Zoological Nomenclature for changing the names.
Things are changing!

Cheers
Werner



M. rosenbergii

Thanks Werner ,

Things are changing!

Cheers
Werner

I really like this statement, bus still have a lot of work to do

How do you tell M. rosenbergii from Macrobrachium dacqueti? They sure look the same to my untrained eye. Mine did come from an aquaculture source.

Hi!

badflash wrote:They sure look the same to my untrained eye. Mine did come from an aquaculture source.

Yes,not only for the untrained eye! I lasts half a century to find some morphological differences between this two species. But hight of the basal crest of the rostrum and (beside a different spinulation of large chelipedes in adult specimen) the live coloration (and change of coloration during development) are good characters to differ these two species.
Read the linked paper, the differences between the two species are described and pictured in detail.

And- according to Daisy Wowor, almost all specimen in aquaculture are M. dacqueti because larval rearing is much more difficult in M. rosenbergii.

Cheers
Werner