Disease Transmission Between Crayfish and Fish

[Jordan_Deus]

Hello,

About four months ago I found an old 25 gallon aquarium. Cleaned it, took it apart, and put it back together. Running a DIY overhead sump (will include pictures).
Water parameters are:
Ph - 7.5
GH - 16 d
KH - 16 d
Temperature - 23-24 C
Two months ago I added a freshwater crayfish (Procambarus alleni). Acclimated to the tank very well, has molted three times so far. I want to add a small school of about ten Rosy Barbs (or Zebra Danios, haven't decided yet) to the aquarium.

I am aware that the fish may get eaten, that's why I have set my eyes on fast moving fish that don't sleep on the bottom of the tank. I am aware of the importance of quarantine, and have done so with fish that went into my 65 Gallon. I was wondering if it is possible to skip that step in this case? That is why I would like to know if disease can be transmitted from Fish to Crayfish. Haven't had much luck with researching this on the internet.

 

[Colin_T]

As a general rule, most fish diseases will not affect crustaceans, and most diseases that affect crustaceans will not affect fish. However, there are a couple that will cross the species barrier including Microsporidian and Tuberculosis.

As for not quarantining new fish before they go into a tank with a crayfish, whilst the common diseases might not cross to the crayfish, if the fish do develop a disease, the medication used to treat them could kill the crayfish. So it's a good idea to quarantine new fish so they don't have to be treated in a tank containing invertebrates.

Danios would be a better choice than rosy barbs because rosy barbs sleep lower in the tank.

 

[Jordan_Deus]

As a general rule, most fish diseases will not affect crustaceans, and most diseases that affect crustaceans will not affect fish. However, there are a couple that will cross the species barrier including Microsporidian and Tuberculosis.

As for not quarantining new fish before they go into a tank with a crayfish, whilst the common diseases might not cross to the crayfish, if the fish do develop a disease, the medication used to treat them could kill the crayfish. So it's a good idea to quarantine new fish so they don't have to be treated in a tank containing invertebrates.

Danios would be a better choice than rosy barbs because rosy barbs sleep lower in the tank.

Theoretically I could remove the fish to a quarantine tank if they developed something, BUT that would stress them out and only cause more harm. Also it's probably better to be safe than sorry, so I'll quarantine them for a month.

I agree about the Danios, was wondering if a 10ish gallon tote, with an air stone (next to air stone a bag of cycled media) , and covering the top of the tank with water lettuce would be a good quarantine setup?

 

[Colin_T]

I have no idea what a 10 gallon "tote" is.

a 10 gallon plastic storage container will work as a quarantine tank. Add an established filter (put the cycled material in a plastic air operated box filter) and a heater, put some plants in and monitor them for a month. If they have no issues then add them to the tank and hope the crayfish doesn't eat them.

 

[NickAu]

Fish and crays do not belong in the same tank unless the fish are there as food for the cray