Reposted by AvaliGAL
You're looking at a Rainbow Tripod Fish (genus Bathypterois) observed on a blackwater dive near Cozumel, MX.
This species demonstrates "ontogenetic vertical migration": young of this species mimic jellyfish near the surface, but descend in depth as they age.
(📷: Frida Yolotzin, Blackwater Cozumel)
