my silver arowana has a wierd habit of chasing his tail in cirles for long periods of time. every now and then he'll lunge, actually get it and then jump into the cover because "something" bit his tail. its kind of funny to watch the first time I saw it i was laughing so hard. does anyone elses arowana do this? i don't think its a bad thing is it? he does it regardless of whether hes hungry or not. hes about 9.5" and in a 55, im looking for a larger tank right now, hell need it in a month or two. oh and at what sixe do silvers start developing drop eye?