Need help - suicidal shubunkans

Help! My shubunkans are jumping out of my barrel pond. I knew I'd lost
a shubunkan over vacation but figured it was ammonia or something.
There was no way to find a corpse in the green water so I didn't know
what happened. I bought three more and put them in the pond on Friday.
All 3 were alive and accounted for Sunday. Today, I could only find
two. I finally looked on the ground, and there were two dead jumpers.

Do shubunkans commonly jump? Do I need netting over the barrel with
them? If so, how do I handle the marginals and water lettuce which are
sticking up out of the barrel? Please help! I don't want to find any
more dead fish on the ground.

Also, while I'm on the subject of shubunkans, one fish is constantly
chasing the other. I can't figure out whether it's aggression or mating
behavior. Will this stress out the chasee, and would a third fish help?
(Assuming I can keep it in the barrel and off the concrete.)

Thanks for any advice.

--
__ Elaine T __
__' http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com