Hokkaido Shrimp ID

[didan]

Could someone please help me in identifying the shrimp in the attached photo. The shrimp is from a freshwater lake in Hokkaido, Japan and I was wondering whether it would be a suitable variety to keep in a tank. Also if anyone knows - how big will this variety grow to, how hardy are they and will standard fish food be ok to feed them. Many thanks.

[Mustafa]

Never seen this shrimp before...but it's most likely a Palaemonid shrimp (i.e. related to Palaemonetes, Macrobrachium etc..etc.). It will do fine on fish food. However, knowing that Hokkaido is very cold during most of the year and the water in the lakes and rivers can be frigid even in the summer, I wonder if they would do all that well at room temperature.

I'll try to find some literature on shrimp on Hokkaido and see what fits the description of the pictured shrimp.

[marusempai]

I don't know what it is either, but having been in Hokkaido, it can and does get dang hot for a couple months in the summer, so they might be fine at room temperature. Do you know which lake in specific they come from? Might help to know.

[didan]

This shrimp was actually caught in a large dam up in the mountains about half a hour north of Tomakomai by car. There are literally millions of this variety of shrimp in the dam - one scoop with a small butterfly-type net at the waters edge can yield about 20-30 shrimp at a time!

[The Fisherman]

Any luck on an ID?

-John

[didan]

Someone told me that the shrimp in the photo is a Pink Shrimp/Aesop Shrimp (Scientific name Pandalus montagui) (Japanese name Tarabagani-zoku). Any comments?

[Mustafa]

It's not a pink shrimp for sure. Pandalus montague are ocean shrimp and look like this:

http://www.seawater.no/fauna/Leddyr/blomsterreke3.htm

Still haven't had time to look Hokkaido's shrimp fauna...

[didan]

Thanks for your help. Any further advice/comments would be really appreciated. I will be in Hokkaido again next week and will try to provide some pictures of their natural environment if it helps. What interests me is that this lake freezes over each winter and I wonder how this shrimp can survive year after year...

[Mustafa]

Just like any other animal survives under a layer of ice. They are in deeper water as the lake does not freeze solid all the way down to the bottom.

[didan]

Thanks - I am learning so much about these amazing little creatures - my kids keep telling me that I have shrimp fever!

[geofied]

didan, I sent the picture to my brother, who happens to be a Marine Biologist (specialty Saltwater shrimp) living in Japan, and asked him if he had any contacts that might be able to ID your very cool looking shrimp. This is what one of his colleagues sent back:

"Attached is probably Palaemon paucidens De Haan, 1844 (or
Palaemon serrifer (Stimpson, 1860) ). It is very common
freshwater species in Japan, and it is distributed from
Hokkado to Kyushu."

Hope that gives you something more to go on, and I hope you enjoy your latest trip to Hokkaido, I'm more than envious

[didan]

Thanks so much for your help geofied.

Your brother is right - the shrimp is a palaemon paucidens.
I double-confirmed this just yesterday with a Japanese marine biologist I met here in Japan.

I am keeping about 12 of these little guys in a tank and they are amazingly hardy - they dont seem to care much about water temp or having their tank water changed every few days. In fact I had a few jump out of the tank and they survived on the ground for maybe about half an hour or more!

Apparently full adult size is 6.6cm which I guess is maybe small compared other kinds of tank shrimp.

Again, many thanks!