There are five different species of flounder found in the oceans, and only one of these flounder species (the Japanese flounder) is found in the Northern Pacific Ocean. The summer flounder, the winter flounder and the southern flounder are all found in the western Atlantic Ocean, while the European flounder is found in the colder waters around Northern Europe.
All five flounder species are very similar in appearance but can vary quite dramatically in size. Flounder can vary from 5 to 25 inches in size depending on the species, but all flounder species have a rounded, flattened body shape with a medium-sized flat tail fin.
The colours and markings of the flounder are dependant on the flounder species, although all five flounder species have adapted to life in the sand on the sea floor and they are often coloured to be camouflaged into their silty surroundings.
Flounder are carnivorous and highly predatory animals. The flounder hides on the sand on the sea floor waiting for potential prey, which the flounder ambushes once it has been spotted. Flounder prey on a variety of bottom-dwelling marine species including small fish, shrimp and crabs.
Due to the secretive nature and good camouflage of the flounder, it rarely spotted by predators. Large fish, sharks, eels, humans, and marine mammals all prey on the flounder when it can be spotted.
Rather than laying her eggs onto an inanimate object or the leaf of a plant, female flounders release them into the water at the time time as the male flounders release their sperm (this form of fertilisation is known as spawning). Once the eggs have been fertilised, the flounder fry begin emerging from them in just a couple of weeks.