From aquatic monsters to giant sea snakes, frightening monsters in the ocean still haunt the imagination of sailors.
Currently, experts claim that sea monsters may still exist. Because scientists are still looking for new species on the ocean floor, the discovery of sea monsters is not impossible.
In 1905, zoologists Edmund Meade-Waldo and Michael Nicoll met a sea snake off the coast of Brazil.
In August 1848, a crew of HMS Daedalus saw a sea creature nearly 20 meters long during a trip to Saint Helena, the South Atlantic Ocean.
At that time, biologists in London claimed that it was most likely a sea elephant.
Some people believe that monsters today can be snake-headed lizards, long-necked reptiles that live at the same time as dinosaurs. However, this theory was rejected by Dr. Charles Paxton from St Andrews University.
If today there are still prehistoric animals, this means there are mistakes in our understanding of fossil records - he said.
Dr. Paxon argues that it is wrong to assume that all large animals living on the ocean floor are being discovered.
8 species of large marine species have been discovered in the past 20 years.
Mystical creatures are the field of ' hidden animals ' - or the search for creatures whose existence has not been proven, like the Loch Ness lake monster and the Abominable snowman.