Here’s a look at some Frequently Asked Questions about this Wonderfully Wacky World Underwater (including some you may never have thought of before) –

Do Fish Fart?

Fish flatulence may not be one of those most common marine mysteries you are dieing to know the answer to, but at the same time it has never failed to create a perplexed look on the recipients face and get everyone thinking…do they?

Well, the answer depends on your definition of a fart. If you consider farting to be the by-product of digestion (gases) expelled solely through the rear-end, then no most fish don’t fart (with the exception of herring and sand sharks). Some may say they’ve observed air escaping from the neither region of a fish after they gulped air at the surface, but this isn’t really a product of digestion, so can it be termed a fart? Most fish do use air to inflate and deflate their bladder to maintain buoyancy which is expelled either through their mouth or gills which can be mistaken for a fart. For example, sand tiger sharks gulp air into their stomachs at the surface which they then discharge out the back door to attain a desired depth. Is that a fart in the true sense of the word? We’ll let you decide. Experts say that the digestive gases of fish are consolidated with their feces and expelled in gelatinous tubes which fish sometimes eat again (eew…I know!). Point being – No farts.

The Herring however, is a whole other story. Research and observation has shown that this fish creates a mysterious underwater noise through their stern (referred to as farting or breaking wind0, which is always accompanied by a fine stream of bubbles. This way of expelling air to create a high-frequency sound is means of communication for the herring and shows no connection to digestive gases or what we call farts except that it looks like bubbles coming out of the anal duct of the fish.

How long do fish live? How can you tell the age of a fish?

Some of the smaller reef fish can have a lifespan of a few weeks or months while some other species like sturgeons can live upto 50 years or more. Longevity information is still sparse, but scientists have learned that a lot of species live approximately 10 to 20 years in temperate waters. Animals with some of the longest lives are the Marion’s tortoise (152 years), the fin whale (116 years) and the deep-sea clam (100 years).

The age of a fish can be determined in two ways. One, by growth “rings” on it’s scales, and the second and more reliable method by the ringlike structures found in otoliths (small bones of the inner ear). The rings correspond to seasonal changes in the environment and can be compared to the annual rings of tree trunks. A series of fine rings are laid down in scales for each year of life in summer, the rings grow faster and have relatively wide separations; in winter, slower growth is indicated by narrow separations between rings. Each pair of rings indicates one year. Because scale rings are sometimes influenced by other factors, scientists often use otoliths, whose ringlike structures also indicate years of life.

Do fish sleep?

It all depends on what you mean by sleep. My dictionary says that sleep is a period of rest in which the eyes are closed and there is little or no thought or movement. That is, sleeping means closing your eyes and resting. The first thing we notice is that most fish don’t have eyelids (except for sharks). Also, while some deep ocean fish never stop moving a great many fishes live nearly motionless lives and many do so on a regular diurnal/nocturnal cycle, some active by day others by night.So we can’t generalize and say that all fish sleep like we do. But most fish do rest. Usually they just blank their minds and do what we might call daydreaming. Some float in place, some wedge themselves into a spot in the mud or the coral, some even build themselves a nest. They will still be alert for danger, but they will also be “sleeping.” Dolphins sleep with one eye open!

What is the world’s largest fish? The smallest?

The largest is the whale shark, which grows to more than 50 feet in length and may weigh several tons; second largest is the basking shark, which may measure 35 to 40 feet long. The smallest fish in the world are the pygmy goby and the Luzon goby, from the Philippines, which are only one-half-inch long when they are full grown..It seldom is longer than a half inch at adulthood, yet is so abundant it supports a fishery.

By considerable measure, the largest known marine mammal and animal on Earth is the blue whale. Mature blue whales can measure anywhere from 75 feet (23 meters) to 100 feet (30.5 meters) from head to tail, and can weigh as much as 150 tons (136 metric tons).

More Questions:

How Do Marine Animals Navigate the Underwater World?

Do fish ever get thirsty?

Which Marine Animal is the Top Predator of the Seas?

Can fish swim backwards?

*Photo Credits: photos by PKMousie, star5112, richard ling on flickr