well i got back home and only to find that out of like 30 crayfish in my pond i only have 2 left. and there the 2 big ones that have been in there the longest. at 1st i thoght it was the eucalyptis (bad spelling) leaves that fall in there that was killing them. anyway the 2 i have that are still alive have these worms on the back moving around. nayone have any idea what they are. thanks