Starfish don't usually feature among the ocean's most terrifying predators, but one of their kin could easily star in the next nightmarish fantasy flick:

Enter the basket star – a strange brittle star with long branching arms that lives mainly in cold, deep habitats. These creatures (genus Gorgonocephalus) typically feed on tiny crustaceans, but other drifters (like this unlucky marine worm) are also on the menu. 

"The arms are covered with hooks and spines!" explains starfish expert Dr Christopher Mah on The Echinoblog. "These hooks function along with spines and the tube feet to capture prey that get too close, and work it down to the mouth!" 

Hitting one of the arms sparks a chain reaction, with more and more branches curling over the prey to immobilise it. (Devil's snare, anyone?)

It's hard to believe this oddball invertebrate is related to the sea stars we often spot in the shallows, but if you focus on the mouth – which sits at the centre of the billowing structure – you'll see it looks quite familiar. These creatures also share some handy skills with better-known species: should one of those twisting arms be broken during a struggle, the basket star will just grow another one. 

Because they lie relatively still while waiting for passing prey, it's easy for the untrained eye of a diver to confuse a basket star with a coral colony. Once hauled above water, however, this animal looks freakishly distinctive. Remember the "alien" that turned up on a Singapore fishing dock back in 2014? That was also a basket star:


ht: Rebecca Helm

Top header image: Alexander Vasenin/Flickr