Courtship and dating can be quite difficult for certain animal species, and they become even more complicated when the environment is almost completely dark and barren of food. Such are the trials of anglerfish who wish to mate in the deep sea, and some of them are really committed to a relationship.
When some anglerfish trace a giant female as she swims in the darkness, they will try to reach her as fast as possible and bite her belly. Once the position is secured, a remarkable phenomenon will take place.
The anglerfish males, which can be smaller than one centimeter in some cases, will release a special enzyme that dissolves surrounding skin, allowing the two fish to fuse as a common circulation system will be established. As the male no will receive nutrients from the female, he may lose some organs, including its eyes.
As such, the fish are nothing more than sexual parasites, with this being the only known example of natural sexual parasitism that takes place beside the existence of identical conjoined twins, according to researchers.
Solving the mystery
For more than 100 years, researchers wondered how the melding works, as even the most accomplished human surgeons have stated that common blood circulation is incredibly difficult to create. Immunosuppressants are also stable in human organ transplants since the body of the receiver will mark the foreign object as a threat.
By studying the immune system of ten anglerfish, species researchers discovered that in some cases, the genes responsible for reactions to invasive agents were missing. A closer look at killer T cells revealed that their ability to attack foreign objects was severely reduced or absent. These discoveries prove that some vertebrate systems can survive without immune features that were deemed to be essential.
More information can be found in a study that was published in a scientific journal.