Lion’s Maine Jellyfish are indeed big. The world record had a bell diameter of 7 and half feet (2.29m) and 120 ft long tentacles (37m).I know this because for this paper, I needed data for the largest and smallest species for every animal phylum.
Being a connoisseur of photos of all size extremes, I immediately noted something was off. Let’s assume the scuba diver is only 5 feet (1.5m) in height. The width of the jellyfish’s bell is about 3 of the scuba diver’s length or 15 feet (4.57m). This would make it twice the size of the world’s largest known specimen. Zoom in on the diver in the photo and you can see a characteristic Photoshop halo. As well, the hue, shadows, and saturation of the diver don’t match the rest of the photograph. I also find it interesting I can’t locate any high resolution versions of this image.
A little searching around the internet and I found a photo without diver but it appears Photoshopped as well. Note the oddly light area where the diver was.
So Lion’s Mane Jellyfish…really big, just not that big