It is not typical behavior for a healthy well fed pleco to go after a healthy fish, but there may be something in the odor of the slime coat of knife fish that attracts them (it's just a thought). This is one of those fishy behaviors out of the ordinary we still lack knowledge on. There's so much to fish, it's impossible to learn it all.
You do seem to be more partial to the dojos and you have great plans for them. They are easier to house and are sought after by a lot of people. They are very compatable with many fish and are a great maintenance fish.
I think more people should get involved in captive breeding. It's a way to 'give back' for what these animals give us considering many are taken from the wild. Some of that take (not all and very few to date, so far, but that could change) does benefit the animal's existance in the wild, such as cardinal tetras. Buying wild cardinal tetras is more eco friendly than buying captive bred. Why? Because it gives the natives in South America a reason to keep the rain forest intact rather than be bulldozed. Some marine fish are also more eco friendly if wild caught, because it keeps the coral reefs intact rather than be dumped on. Others however, should be bred in captivity to leave the wild populations intact and those are going to be species where their natural habitats are intact and without threat to those habitats from development.
Now I'm just babbling if you don't mind
...lol
There's this guy I know I go over to visit him and his wife. He turned me on to African Cichlids. He's got a nice 120 gallon tank and a 60. In his big tank he's got all sorts of Africans, catfish, loaches, etc. Same in the other. He's got fish living together most people fear to try to mix. Ever hear of red eye tetras living with Tanganykan African cichlids? How about dwarf frogs living with them? ...and cory catfish too!! LOL. He's got living in the big tank with the Malawi cichlids a bunch of rubber eels. Three pairs of which I gave him. They're actually amphibians, not eels but look like eels. Really neat animal. Weird to watch them stick their head out of the water and drink air. Their head reminds me of a sock puppet...LOL...with almost no eyes. Just a silky dark gray sock hand puppet. Very unique. They are listed as highly difficult to breed in captivity and you cannot get any unless they are captive bred. They reside in the drug/war strickened territories of Columbia. No one collects them anymore. If they do, they risk being killed by rebels and militia. Certainly not worth it. We lost a great animal to observe, learn and enjoy. These critters breed all the time in his tank!! He's got babies swimming in there right now...many years after I've given mine to him and there's a pregnant female for like the fifth or sixth time. They breed once every other year and gestation is one year. He has at one point in time looked into breeding them for conservation and there are groups who would help. He did seriously consider, but for whatever reason, he backed off from it. I think he's crazy. He's sitting on a great conservation project and a gold mine to the aquarium industry. He's been wanting to turn his tanks into marine tanks for a few years now. If he ever does, I get the eels back and I know how he keeps his tank to replicate and continue the breeding
Hope this inspires you...
