My watchman goby is a jumper also. He jumped into my overflow, went down to the sump, bypassed the skimmer, jumped over the baffle into the fuge, some how went thru the 3 baffles to end up in the pump section. Good thing I left the sponge filter on the pump. Not sure how long he was there, noticed him when I took the sponge off the pump to clean it. He always hides under the rocks. Seen him only a few times, he'll make an appearance for about 3 days, then goes back under the rock for months. Cute little guy tho...