Engineer goby hate crimes?

[EnderG60]

Ive had two engineer gobies(i know they are actually blennies) for 3 years now. I got them both as babies and they have been together since. I had to take my tank down due to a crash last year and they have been living happily in my quarantine system since then. No problems at all they shared a length of PVC as a home for the past year.

Well this past weekend I finally got my tank back up and put them in(and some clowns and chromis that had survived the crash)

Next day I wake up to see the smaller of the two has had the crap beat out of him and he is not going to make it.

The only two explanations I can come up with, are he either got stuck in the rock work and hurt himself getting out, or the larger of the two beat him up over territory...but I have never heard of engineers being aggressive at at all.

Has anyone else ever had an engineer go rouge?

 

[DustyReefer]

I had one almost kill a juv. majestic angel before. The majestic liked to hang out in the entrance of the engineers cave, but the engineer didn't like it... One day he got ahold of him and tore him up pretty good. He was definitely one of the more aggressive fish I had at the time

 

[ilikefish34]

I've seen where aquarist will have them for months and years without a problem and then they flip a switch out of nowhere. Also, it could stem from the environmental changes. I had two Yellow Watchman Gobies that where paired up in a LFS. They were inseparable in a 10 gallon nano reef for about 3 months. Then they were moved to a 50 gallon softy reef after breaking down the 10 and they were still together. 4-5 months later, I decided to move them to the 125 gallon reef and the female beat the crap out of the smaller male within the first few minutes (i witnessed the beat down and it was definitely not any other tank-mate that was harassing him). They stayed on separate sides of the tank for several months. I moved them back to the 50 and they were fine. Moved them back to the 125 and they were fine still. We can follow all of the rules, but in the end, fish can be strangely unpredictable.