The anglers are deep-sea fish that settle their home more than a mile deep in the ocean. The female anglers have a formation that looks like a worm on their forehead, which she uses to attract other fish. But the main problem is that, at that depth there is not much light and it often happens that the anglerfish will die of starvation.
To resolve the starvation possibility the anglers developed some sort of a light on the forehead formation and thus the fish can catch fish and eat them. This light does not emanate any heat and it is the result of a reaction produced by two compounds the fish creates. It is amazing how the evolution process made it so this fish survive so very deep in the ocean.
The reproduction process of the anglers is also special. The females release the eggs that float to the surface of the ocean and there is where they form some sort of a gelatin mass and then hatch. The young anglers mature at the surface of the ocean. One may wonder then why is there any need for a male anglerfish and the answer is very simple. At a certain point in the evolution process the male and female meet and the male bites the abdomen of the female leaving a parasite that will always remain there and this may contribute to the future hatch of other anglerfish.
In contrast to other fish the anglers have an air sack instead of a swim bladder. This helps them to maintain equilibrium in the water and prevents them from sinking. Because they live in the depth of the ocean the air sac does not make them easy prey, as it would be if they lived on the surface. They also have a special body than can stand up to 2000 pounds of pressure and thus prevents crushing.
