The last year, a new parasitic male was found.  A unique characteristic of anglerfish is the parasitic dwarf males. But only half of anglerfish species, those in the Ceratioidei sub-order, possess these unique males.  In these anglerfish species, females are 10x larger than males.  The males are essentially free living sperm packs.  Upon locating a female, anglerfish males will bite her side.  This biting triggers hormones that fuse his lips to her and dissolve his organs.  Eventually, he becomes nothing more than a testis on her side.

One anglerfish family, Centrophrynidae, contains only one species, Centrophryne spinulosa. Despite being found in the Atlantic, Pacific, and Indian oceans, the species is only known from 45 individuals. and in 2013 Vieira and colleagues described a joined female-male pair caught in 2010 off Savage Island, near Portugal.

The female is the largest known of the species and attached to her belly, most likely recently given the fusion process looks incomplete, is a male.  The authors note that this pairing is extremely rare.  Of all known anglerfish specimens these parings are only known from ~5%.  This suggests pairings in the wild are extremely rare.