Filter shrimp ID please

Dusko · Post by **Dusko** » Mon Sep 18, 2006 8:05 am

My LFS got this lovely looking filter shrimp and they say it is called Atrax spinepes , and of course I Googled and nothing comes out.
I believe that this shrimp is the Atyopsis moluccensis
aka Bamboo Shrimp, probably male.
The shrimps in the photos are approx. 5-6cm.

Since I am not sure, I thought petshrimp.com might have the answer.

Kind regards, Dusko.

YuccaPatrol · Post by **YuccaPatrol** » Mon Sep 18, 2006 8:47 am

The store mis-labeled these. They are an Atyopsis species, but I cannot tell you if they are moluccensis or Atyopsis spinipes. I did a brief search through the scientific literature and it appears that the two species have been confused many times in the past century and a wholesale importer/exporter is probably unlikely to really care which is which (especially if they cannot get the genus correct)

I did find a detailed description of Atyopsis spinipes and will upload a couple pages from a journal article which could help you to identify them. Unfortunately, I do not have the same for moluccensis. . . .

Regardless of the specifics of identification that will require either dissection or at least a dissecting microscope, you definitely do have an Atyopsis.

The bottom two photos appear to show females. Males have a much stouter front pair of walking legs compared to the other 2 pairs

badflash · Post by **badflash** » Mon Sep 18, 2006 9:23 am

I do not think this is A. moluccensis due to the coloration and head. They are really nice shrimp!

YuccaPatrol · Post by **YuccaPatrol** » Mon Sep 18, 2006 9:52 am

Here is some information helpful for identifying A. spinipes

Post by **Mustafa** » Mon Sep 18, 2006 9:53 am

badflash wrote:I do not think this is A. moluccensis due to the coloration and head. They are really nice shrimp!

It's really hard to say. Both species can be variable in color and are hard to tell apart just by looking at them (unless you have seen thousands of both species I guess....but who has?). For all I know, they might even be the same species (scientists have been known to describe the same species twice based on just a few speciment, disregarding intraspecies variation) or subspecies of each other.

YuccaPatrol · Post by **YuccaPatrol** » Mon Sep 18, 2006 10:00 am

And I'll add one photo from my tank of my Atyopsis sp.

I had always just assumed it was moluccensis until today, but without a key comparing the two species, I can only be positive of the genus.

Like Mustafa said, coloration is variable. Mine will be bright red/orange most of the time, but will go pale tan/grey after water changes.

If you check out the species description above, you'll see that the two have been confused by scientists in the past and I have not (yet) found a definitive key to compare the two

YuccaPatrol · Post by **YuccaPatrol** » Mon Sep 18, 2006 10:07 am

The definitive comparison of the two species is not yet available online. I'll see if I can track down a hard copy of it and scan it. But for now, here is the abstract and information necessary to find this key.

The Atya-like Shrimps of the Indo-Pacific Region (Decapoda: Atyidae)
Fenner A. Chace, Jr.
54 pages, 24 figures
1983 (Date of Issue: 13 October 1983)
Number 384, Smithsonian Contributions to Zoology
Display: Online version not yet available | Full Description (from SIRIS)
Abstract

The shrimps recognized in this study comprise six freshwater species that have often been referred, untenably and sometimes in synonymy, to the genus Atya. Three of the species are here assigned to the reestablished genus Atyoida: A. bisulcata, confined to Hawaii; A. pilipes, ranging eastward from eastern Indonesia and the Philippines to the Marquesas and Gambier islands; and A. serrata, possibly limited to Madagascar and smaller islands in the tropical western Indian Ocean. Two closely related forms compose the new genus Atyopsis: A. moluccensis, ranging through Thailand and Malaya to Indonesia and perhaps westward to Sri Lanka and northeastward to the Philippines; and A. spinipes, apparently inhabiting the eastern Lesser Sunda Islands and extending northward through the Philippines to Okinawa and eastward as far as Samoa. Atya striolata, occupying streams along the east coast of Australia, is assigned to the new genus Australatya. Keys are provided to the genera and species and, for each of the latter, there are a complete synonymy, review of the literature, references to published illustrations, a diagnosis, color notes if available, size limits, the known range and material examined, variations observed, ecological information, life-history notes if any, common names, and economic importance. Special attention is paid to the heteromorphism of the chelipeds in Atyoida, especially as displayed by a series of several hundred specimens of A. pilipes from Palau, Caroline Islands.

edit: it looks like the university library has this! Next time I need to go there, I'll get a copy for us!

Dusko · Post by **Dusko** » Mon Sep 18, 2006 11:25 am

This sure is some good reply

This info is great. I can see know it does look more like the A. spinipes. I will try to get one so I can observe it carefully.
Thanks again.

Regards, Dusko.