A Goldfish's Senses

Smell a goldfish has nostrils called nares. But unlike us, who breathe through our noses, goldfish cannot. Their nostrils, located above the mouth and below the eyes, are really only small pits of scent buds. These are not attached to the respiratory system, but rather, via a nerve, are connected to the brain.

The sense of smell is strong with goldfish, and is highly important in the search for food and in mating. Water enters the nostril and is passed over membranes. It is then passed out the same way it came in. Sometimes contaminated water can disorient a fish, making finding food or mating difficult.

Taste Most of a goldfish's taste buds is located on the lips and all over the mouth. There are even taste-buds on the outsides of the lips. This is an advantage for the goldfish in the hunt for food and for a mate. Goldfish have no tongues.

Touch Lateral line adaptations give the goldfish the best sense of what we mean when we say touch. The lateral line is a series of dimples in somewhat of a line across the fish's side. These dimples are thermo sensory nerve endings connected to the brain, and when pressure is exerted on them, or when vibrations occur, the fish can feel them right away.

Hearing Goldfish have no outward ears. Their hearing lies entirely inside the skull. They have a pair of membranous sacs, each of which is composed of two chambers, the utricles or dorsal sacs and the succubus or ventral sacs.

Sound vibrations pass through the water, through the fish's body, and reverberate in this inner ear. The succubus contains the ear stone or otolith. It is this complex that gives a goldfish its sense of hearing, and like our own inner ear, its sense of balance. We know for sure that fish make sounds during eating, fighting and mating, and hear intruders when being attacked. Hearing is an essential tool for goldfish survival.

Vision the eyes of fish operate somewhat like our own, except that they lack eyelids and their irises work much slower than our own. That is why if the light is turned on suddenly, fish seem to go into shock. Because it takes their eyes longer to adjust to the change in light, they are temporarily blinded. Their eyes eventually adjust, though it may take a couple of hours.

Also, fish have flat corneas and fiat-shaped lenses, causing them to be particularly nearsighted. This is not a great handicap, since visibility in ponds and lakes is not always very good. Also, since these fish were bred for hobbyists, nearsighted vision is all that is really required.

On the other hand, goldfish are able to detect color. Also, since their eyes are on either side of their heads, they have monocular vision as opposed to binocular vision like us (which we find useful in judging distances). Goldfish eyes have little movement

The eyes are efficient at spotting food and dangers, including other fish. Highly developed goldfish varieties, which have bubble eyes or telescope eyes, are thought to see only upward. The Bubble Eye variety, which develops large, fluid sacs underneath its eyes, is believed to suffer vision loss as well, but no one can be sure. There are cases of other species, tropical fish that have no eyes at all and live full lives. However, the above-mentioned goldfish strains, when maintained with ordinary care, suffer no great problems when housed with other fish of the same type.