Behold! The magnificent Melibe genus of sea slugs… These transparent nudibranch mollusks are active carnivores which trap fast-moving, free swimming prey with a powerful weapon—their head. I don’t mean this figuratively: their transparent heads are expanding nets which shoot open and engulf small animals like copepods, shrimp, hydrozoa, and tiny fish fry. Their lethal hoods are surrounded by a mane of sensory tentacles, which make the slugs superficially resemble jellyfish and Venus fly traps).

Hooded nudibranchs of various species live in tropical and temperate waters around the world (I was unable to ascertain whether they lived in the Arctic or not…maybe because they don’t or maybe because we don’t yet know). They tend to be diminutive animals measuring under 10 cms (4 inches) long which live hidden among seaweeds and kelps. The creatures are hermaphrodites and emit a sweet smell when removed from the water. In case they were not sufficiently bizarre for you, they escape predators like crabs, fish, and cephalopods by shedding their cerate (the lateral outgrowths protruding from the slug’s body).

I have failed to do this slug justice (because WordPress has disabled video posting), but here is a link which shows the disquieting predatory head-expansion. I can hardly think of a creature more alien in appearance or manners, and yet they are quite appealing. The amazing Eliza Heery thought so too, and dressed as one for Halloween. What a world…