Ornamental Fish Q&A 22

This question was provided by Manson Publishing as part of the OVAL Project. See more Ornamental Fish Q&A.

This Moorish idol is markedly exophthalmic and on close inspection a large air bubble can be seen behind the globe.

Question	Answer		Article
What is this condition called?	Supersaturation or gas-bubble disease.		Link to Article
How does this problem develop?	The most common cause of this problem is a cavitating pump which literally supersaturates the water with atmospheric air (meaning the majority of the gas will be nitrogen). Excessive oxygen production by algae and other plants is a less frequent cause. Over-aerating an aquarium with air bubbles from an air stone can, but rarely does, lead to supersaturation disease.		Link to Article
How is this condition treated?	Treatment usually involves finding the source of the excessive gas and eliminating it. In the case of a cavitating pump, filling the sump or reservoir or locating a leak in the system usually solves the problem. Air bubbles under the skin and within the fins will usually resolve within a day or two. Air bubbles in the circulatory system, especially in the branchial vasculature, can be acutely fatal.		Link to Article
List four other general causes of exophthalmia in fish.	Ammonia toxicity, ocular parasites, septicemia, and neoplasia.		Link to Article