The first forms of animal life on our planet came from the oceans. Before there were any land animals there were animals in the sea; marine life is highly evolved and most species were well established long before dinosaurs roamed the earth. There are over 25,000 identified species and it is estimated that there may still be over 15,000 species that have not yet been identified making new discoveries in the ocean still possible, even today. Follow along for some “fishy facts” that just may surprise you.
An adult flounder has two eyes situated on one side of its head, but at hatching the eyes are located on each side of its brain. One eye migrates to the other side of the body as a process of metamorphosis as it grows from larval to juvenile stage. As an adult, a flounder also changes its habits and camouflages itself by lying on the bottom of the ocean floor as protection against predators.
Seastars have a small eyespot at the end of each arm which senses light, but is not sophisticated enough to allow them to see images as we do with our eye. While fish propel themselves with their tails, seastars have tiny tube feet to help them move along.
Pufferfish are poor swimmers, but can quickly ingest huge amounts of water to turn themselves into a virtually inedible ball several times their normal size. A predator that manages to snag a puffer before it inflates won’t feel lucky for long. Almost all pufferfish contain tetrodotoxin, a substance that makes them foul tasting and often lethal to fish.
Every night, certain species of parrot fish envelope themselves in a transparent cocoon made of mucous secreted from an organ on their head. Scientists think the cocoon masks their scent, making them harder for nocturnal predators, like moray eels, to find.
When an octopus gets upset, it shoots a stream of black ink. The ink even contains a substance that dulls a predator’s sense of smell, making the fleeing octopus harder to track.
Though they look defenseless, sea cucumbers are able to distract a predator by expelling their inner organs through their anus at the predator. They use their anus to breathe and excrete digested food and even have the ability to regenerate their organs once expelled.
The cleaning process includes the removal of parasites from the animal’s body (both externally and internally), and can be performed by various creatures including cleaner shrimp and numerous species of cleaner fish, especially wrasse. When the fish approaches a cleaning station they will behave in an unnatural way to show the cleaner fish that they want to be cleaned and pose no threat; this can be pointing in a strange direction and/or opening the mouth wide. The cleaner fish will then eat the parasites directly from the skin and will even swim into the mouth and gills of the fish it is cleaning.
When they are active, sea turtles must swim to the ocean surface to breathe every few minutes. When they are resting, they can remain underwater for as long as 2-1/2 hours without breathing. Sea turtles can see fairly well in water but are shortsighted on land. They secrete excess salt from their body by ‘crying.’
Most fish have an excellent sense of vision, touch, and taste. Many possess a good sense of smell and even hearing, while some fish have eyes that are the same size as their stomach!