Scientists at the Monterey Bay Aquarium Research Institute in Moss Landing, California have published what is probably the first ever footage of an extremely rare species - the bizarre and scary anglerfish. The footage was taken 1900 feet ( 600 meters) below sea level.
Anglerfish are strange even for the deep sea. They have big teeth protruding out of their mouth, and a very specific way of feeding: a fleshy growth from the fish's head (the esca or illicium) acts as a lure - hence the name "anglerfish". They also exhibit extreme sexual dimorphism - the males and females have extremely different appearances and functions.
Basically, because individuals are very rare in the deep sea, encounters are also very rare - so mating can be quite a problem. When scientists first started capturing ceratioid anglerfish, they noticed that all of the specimens were female. These individuals were a few centimetres in size and almost all of them had what appeared to be parasites attached to them. It turned out that these "parasites" were highly reduced male ceratioids. This type of pseudoparasitic reproduction is truly amazing - the males have no other function than finding a female as fast as possible. Without it, they cannot feed.
Males have extremely sensitive olfactory sensors - they can smell very good. When a male finds a female, he bites into her skin, and releases an enzyme that digests the skin of his mouth and her body, fusing the pair down to the blood-vessel level. This ensures that the female has a male nearby whenever she is fertile. It's a type of parasitic mating, as the male will continue to live, sucking up what he needs from the female's blood system.
Anglerfish are very hard to study because they live so deep in the sea and they don't survive long in surface conditions. Of all the 10 species, there are about half a dozen footages of them.
This specimen, like many others, although looking extremely scary, measures below 10 cm.
