Axolotl's fighting advice?

[Richatops]

Hi, I was wondering if anyone had any advice, I've got 2 axolotls (Will & Grace) (not totally sure on genders, think one is male and the other female as they different shaped heads), I've had them nearly two years now but recently one has become increasing aggressive towards the other. I've seen it get the other one's front leg all the way up to the shoulder into its mouth and shake it quite violently for about 10 seconds. The leg was a bit red for a little while and he (again not sure on genders) didn't seem to favour walking with it for a couple of days. However they did seem to be friends after this and sit next to each other as if nothing had happened. Today I got home to find the same one that was attacked with a nasty wound on his back leg, it looks like the other one got the leg in its mouth and he pulled back to try and escape but has scrapped the skin back, leaving it red and possibly bloody and very sore. I have put a divider in the tank to separate them into two halves of the tank for now. Should I leave them separated for a few days to calm them down? Unfortunately the one with the injury has always been more timid and I believe has some potentially genetic problem, one of his eyes is sunken in and smaller than the other and he came with a missing finger that has never grown back so he can't keep being attacked like this, however I really don't want to have to keep them separate forever.
The tank is about 140 litres (approx. 110cm x 40cm x 50cm) I've recently abandoned using tank lights so the tank is kept darker and cooler, at an average of 17oC. I do a weekly water change of 27 litres, the substrate is sand. I've replaced live plants with fake plants so there shouldn't be much contamination in the water and the filter is set to allow plenty of oxygen in the water. I've been getting more fake plants lately to make little tunnels they can hide in as I know they like to hide. Both feed well on earthworms (and the occasional piece of chicken), the aggressive ones appetite is unending and snatches food vigorously but is fed every day, I don't want to decrease the number of meals in case it increases aggressive behaviour towards the other one.
Apologies for the lengthly post, would appreciate any advice anyone has.

 

[pent565]

Try feeding them at opposite ends of the tank, and feed the aggressive one as much as he'll eat in a sitting. Telling genders should be easy after two years, just look at the area just behind between the legs, at the base of the tail. If there is a large protruding bulge, male. Small bulge or no bulge, female. I've never heard of adults attacking eachother like that...

 

[Kaysie]

Axolotls have a very strong food drive. In their natural habitat, they're the top predators (at least historically). They also snap at anything that moves.

It could be that it's just a case of mistaken identity, rather than bullying. But if it's happening frequently, it may be best to separate them.

Pent's suggestion of feeding them at opposite ends of the tank is fantastic. Usually what I do is dangle a worm in front of the aggressive one, and drag it over to the far corner of the tank, and then feed the timid one while the aggressive one is preoccupied. Usually by the time I get the timid ones to eat, the aggressive one is done and gets another worm bit.