# Feeding preference of an introduced population of Cherry Shrimp



## dw1305 (2 Jan 2019)

Hi all,
I was looking at an <"_Asellus_ food preference paper"> (apparently the shed leaves of Alders _Alnus_ spp.), and it linked to this paper, about the Cherry Shrimp_ (Neocardinia davidi). _Schoolman & Arndt (2017) <"Leaf-litter preferences of the introduced freshwater shrimps _Atyaephyra desmarestii_ and _Neocaridina davidi_"> _Crustaceana_* 90. *which also points towards Alder leaves as a preferred food item. 





> ......while the ornamental Species _Neocaridina_ _davidi_ was released in 2009 into a small tributary of the Erft River (North Rhine Westphalia, Germany), where it has thrived. Both species use leaf-litter as a significant food source. In this study, we assessed a reproducible method to compare the preferences of this two shrimp species for decaying leaves of four different species of deciduous tree: alder (_Alnus glutinosa_), Italian poplar (_Populus xcanadensis_), pedunculate oak (_Quercus robur_) and goat willow (_Salix caprea_). We also determined the relevance of _A. desmarestii_ and _N. davidi_in leaf-litter breakdown. Adults of both species showed a significant preference for leaves of alder and Italian poplar
> 
> ....... Diurnal consumption rates were determined for _N. davidi_. It consumed 51.0% leaf litter dry weight per body dry weight per day. _Alnus_ and _Salix_ leaves (including biofilm) made up the majority of the diet of _Neocaridina_, followed by _Populus_ and _Quercus_ leaves
> 
> .........Our results demonstrate the distinct relevance of leaf-litter in the diet of freshwater shrimps, and their role in leaf-litter breakdown. While the invasion potential of _A. desmarestii _seems to be relatively low, at least for now, _N. davidi_ has thus far been a very successful invader.


I've just looked it up, and the Erft river is "thermally polluted" and has _Vallisneria_ etc. growing in it. 

cheers Darrel


----------



## zozo (2 Jan 2019)

dw1305 said:


> Hi all,
> I was looking at an <"_Asellus_ food preference paper"> (apparently the shed leaves of Alders _Alnus_ spp.), and it linked to this paper, about the Cherry Shrimp_ (Neocardinia davidi). _Schoolman & Arndt (2017) <"Leaf-litter preferences of the introduced freshwater shrimps _Atyaephyra desmarestii_ and _Neocaridina davidi_"> _Crustaceana_* 90. *which also points towards Alder leaves as a preferred food item. I've just looked it up, and the Erft river is "thermally polluted" and has _Vallisneria_ etc. growing in it.
> 
> cheers Darrel



Intersting... I dumped some Cherries in the 125 litre outdoor bucket curious if the would survive and thrive.. Well if they survive Germany they also will in my big bucket.. North Rhine Westphalia is next door for me, 45 minutes drive and i can catch wild cherries in the Erft.. haha.

Also had a few outdoor till november and took it indoors. I noticed them getting more robust and dark red almost brown in color. It was pretty cold when i took 'm in, but they do not seen to be bothered.


----------



## rebel (3 Jan 2019)

https://www.timeanddate.com/weather/germany/dusseldorf/climate

Looks like the temps don't drop below 1 degree C. Perhaps that's the limit?


----------



## zozo (3 Jan 2019)

rebel said:


> https://www.timeanddate.com/weather/germany/dusseldorf/climate
> 
> Looks like the temps don't drop below 1 degree C. Perhaps that's the limit?



Could very well be, the North West of Germany also is rather low country, relatively lower at sea level. It's near to our Dutch border at the same longitude as where our country the Netherlands (low lands) get rather low at 5m above sea level getting even lower further north.

The more you go South and East you'll go up the mountains, i live 135m above see level at the foot hills of the German Eifel and Dusseldorf is 45 minutes N-E down hill from my place. And my average winter temps are already a tad lower. It's funny to live at such a climate border, sometimes i only have to drive less than 20km S-E to go skiing in the snow and still have +0 temps at home..  But it also can drasticaly shift we can have -18°C too occasionaly.


----------



## tam (3 Jan 2019)

I'm sure I've read somewhere someone had them in an outside tub that had ice on the surface (although I don't know how insulated/what the temp was down the bottom).


----------



## dw1305 (3 Jan 2019)

Hi all, 





dw1305 said:


> 've just looked it up, and the Erft river is "thermally polluted" and has _Vallisneria_ etc. growing in it.


It says in <"Alien aquatic plants in a thermally...... "> that water temperature doesn't fall below 10oC. This paper also has a map.

I don't know how far the cherry shrimps have spread, but presumably the water gets cooler as it goes down-stream from the warm water source (the drainage from lignite mining and associated power station).

This one <"Population dynamics of the invasive freshwater shrimp _Neocaridina davidi_ in the thermally polluted Gillbach stream (North Rhine-Westphalia, Germany)"> says at least one cherry shrimp has been found in the lower Rhine, and this one <"On the occurrence of three non-native cichlid species including the first record of a feral population of....."> says 





> In Germany, non-native convict cichlids (_Amatitlania nigrofasciata_) and tilapia (_Oreochromis_ sp.) have established populations in the Gillbach, a small stream that receives warm water discharge from a local power plant. Here, we report on the discovery of spotted tilapia (_Pelmatolapia mariae_) in the Gillbach, the first record of a reproducing population of this species in Europe.


cheers Darrel


----------



## mort (3 Jan 2019)

tam said:


> I'm sure I've read somewhere someone had them in an outside tub that had ice on the surface (although I don't know how insulated/what the temp was down the bottom).



I've seen this as well. I think someone had them in a 100 gallons vat that was above the ground. They also kept ricefish in the same way. May have been cory mcelroy and I know he's now based in Washington.


----------



## rebel (4 Jan 2019)

I didnt realise thermal pollution was a thing!


----------



## dw1305 (4 Jan 2019)

Hi all, 





rebel said:


> I didnt realise thermal pollution was a thing!


There is a UK "warm water" thread in <"Remember the Hotties...">.

cheers Darrel


----------

