Our first weird jellyfish is one of the largest deep-sea jellyfish species in the ocean. You can find the black sea nettle jellyfish in the Pacific Ocean off California and Mexico, and it is known to grow to a diameter of about one meter / three feet in diameter with arms longer than five meters / 16 feet.
Scientists know little about this jellyfish, and it was only discovered in 1989. The bell on mature animals has an almost black opaque coloration unique amongst jellyfish found in the area.
Typically jellyfish and other animals use bioluminescence to lure their prey. However, the atolla jellyfish appears to use it to flee when threatened.
Large blooms of black sea nettles have been spotted at the surface in waters off Southern California and Baja California in 1989, 1999, and 2010. However, it is a mystery why the animals congregate together in such large numbers in shallow water.