My Crayfish Are Dying :(

[Spishkey]

we've kept crayfish for about 6 months, they've grown wonderfully, we had 10 but in just the past week we've lost four, (ive just fished out the two biggest )
i dont know whats happening
4 we're kept inside, 6 were living outside, but a few weeks back we made a crayfish only tank for them and put them all together, now this week disaster strikes. do crayfish suffer diseases? does anyone know what is safe to try and treat them with if they are sick?

 

[raptorrex]

we've kept crayfish for about 6 months, they've grown wonderfully, we had 10 but in just the past week we've lost four, (ive just fished out the two biggest )
i dont know whats happening
4 we're kept inside, 6 were living outside, but a few weeks back we made a crayfish only tank for them and put them all together, now this week disaster strikes. do crayfish suffer diseases? does anyone know what is safe to try and treat them with if they are sick?

could do with a bit more info here! some pictures of the Crayfish, rough sizes and temps of the tanks pools used.

Crayfish do suffer form various illnesses. the most often encountered, in the wild is Crayfish plague ( a fungal infection that there is no cure for) which has decimated the indigenous populations throughout the world, since its introduction from the USA. they also suffer form bacterial infections!

 

[Spishkey]

heres a pic

we were told they were marbled crayfish but after much research i have my doubts.
the ones that have died had all recently shed their skin, and were all the larger ones.
the survivors are all younger smaller ones.
ammonia nitrite both 0 nitrate 5 temp 24/25 degrees.
60L tank, rock substrate, rock formation deco, stingray filter, hydor ario airpump.
fed on crayfish pellets.

could the ones we moved from outdoors have brought in a disease? they were kept in a 300L tank on the balcony but it is getting cold so we brought them inside. they were outside for about 2 months, before that they were in the indoor tank with the others. the larger ones that died were roughly 2+inches?

 

[WILDER]

Any symtoms to go on.
Any signs of flicking and rubbing.
What do there gills look like.
Do they look pale or darker in colour.
What does it look like when they go to the toilet.
Any sores or red streaking on there bodies.
Any laboured breathing.
Any excess mucas on the fish.
Did you match ph and temp when you transfered them to the tank.

 

[raptorrex]

one thing is sure. these are Marble Crayfish. as such a great danger to to other Crayfish. breed for farming and food. being a- sexual, one can produce many. should only be kept in secure Tanks. never in ponds or pools.