This might sound a littlie fishy, but many offices today have fish, whether in bowls, tanks, or even in ponds. There is a soothing, relaxing, and beautiful aspect to most fish. And further, feng shui, the ancient Chinese philosophy that focuses on spatial position and arrangement, holds that goldfish can bring good luck and prosperity, and that's not bad for the workplace either.
However, from your manager's perspective, you are violating a work rule. When companies turn their back on one rule, employees wonder if any of the rules truly need to be followed. And further, if you can bring in one goldfish, can another employee bring in twenty, or even bring in more exotic fish with aerated fifty-gallon tanks? Then, what about other pets? Can an employee bring in a cat? What happens when the cat spots the fish?
Although some companies allow certain pets at work and often find that they are a welcome addition, that's not where you work. You should continue to discuss this matter with your manager and human resources department if there is one, but there is no point in making this a major battle. Surely you have more important fish to fry, so to speak.
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