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Leaping Fish and Nerves On End
Tank HeavenQ: Following a recent bereavement, we’d like to know why our fish keep jumping out of their small aquariums.
Fish jumping out of small tanks is a common problem for enthusiasts, and it’s why some people put a glass cover on their aquariums. There are a few theories. In the wild, the fish may jump to rid themselves of ectoparasites. They may also be trying to avoid predators or unpleasant interactions with other creatures, or even to show off to other fish in some previously unknown courtship or territorial ritual.
To captive fish, the air on the other side of the aquarium glass looks like water. In fish lore, the water is always cleaner on the other side. In the meantime, our sincere condolences for your loss.
Nerve Endings
Q: What bodily changes cause us to have a dry throat when we’re nervous?
When you’re nerve-ridden during public speaking, the body is set into the fight-or-flight state. This is caused by an activation of the autonomic nervous system. It’s seen throughout the animal kingdom and has evolved to help animals deal with danger—when escaping from predators, for example.
The nerves are selectively activated, depending on how important they are for response. Because eating is not considered to be vital at this time—you want to just get the heck out of there—the nerves that control the salivary glands are suppressed, so your mouth dries up. Your pupils dilate, and the blood vessels to your muscles and heart widen to get blood to the most important organs for whatever action is necessary.
In a tense or dangerous situation, your body shuts down all unnecessary functions, including the digestive system. Your salivary glands are part of it. You don’t need to digest your last meal if a lion is trying to make you his next. This is also where butterflies in the stomach come from.
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