If placed within the normal helmet slot (meaning not the vanity slot), the breath bar will appear and the player wearing it will start to drown; however, with an activated Breathing Reed or a Gills Potion, they will not drown. The Neptune's Shell accessory will not have its effect, although it will still function properly underwater.
If placed within the social equip slot, the breath bar will not appear and one will not drown. This is because social slot equipped items do not give any effect. When used in conjunction with the Gills Potion, the Fish Bowl allows for breathing both above and under water. Prior to 1.2, this was one of the only ways to be able to breathe in both locations.
When the player walks, the two fish move around the bowl. The faster the player walks the faster the fish will move. The fish do not move if the player is using an item.
When a player equips a Fish Bowl, their hair will disappear. This is easily seen when one takes damage: Upon the activation of transparency, they will be visible with no hair. The hair renders properly once the Fish Bowl is taken off.
On 1.0.4 update Fish Bowls texture changed, but it still uses old texture when worn on head.
Fish Bowl can be placed on flat surface items or ground, and it will have only one gold fish swimming in it.