|Humpback Anglerfish, Melanocetus johnsonii|
They are bony fish of the teleost order Lophiiformes (Garman, 1899) and one of the most interesting, intriguing yet creepy, species on this planet.
There are over 200 species of anglerfish, most living in the pitch-black depths of the Atlantic and Antarctic oceans. They always look to be celebrating a birthday of some kind, albeit solo. This party is happening deep in our oceans right now and for those that join in, I hope they like it rough. The wee candle you see on her forehead is a photophore, a tiny bit of luminous dorsal spine. Many of our sea dwellers have photophores. We see them in glowing around the eyes of some cephalopods.
These light organs can be a simple grouping of photogenic cells or more complex with light reflectors, lenses, colour filters able to adjust the intensity or angular distribution of the light they produce. Some species have adapted their photophores to avoid being eaten, in others, it's an invitation to lunch but not in the traditional sense of that invite. In the anglerfish' world, it's dead sexy, an adaptation used to attract prey and mates alike, sometimes at the same time.
He might be one of several potential mates. Each will take a turn getting close to her to see if she's the one. For her, it's not much of a choice. She's not picky, just hungry.
Mating is a tough business down in the depths. A friend asked if anglerfish mate for life. Well, yes... yes, indeed they do. Lure. Feed. Mate. Repeat. Once connected, the attachment is permanent. Her body absorbs his over time until all that's left are his testes. While unusual, it is only one of many weird and whacky ways our fishy friends communicate, entice, hunt and creatively survive and thrive. Ah, this planet has some evolutionary adaptations that are enough to break your brain. Anglerfish are definitely in with that lot.