Mini-monsters of the deep: carnivorous sponges

Image by Pierre Denys de Montfort, 1801. In public domain.

When we think of monsters from the deep, we tend to think of things like the giant squid I wrote about recently, or the vampire squid: the sort of kraken-like beastie that leaps out of the ocean and pulls sailors from the crow’s nest. Or there’s the goblin shark, which I mentioned in this post. Or the cookie-cutter shark, a fast little mover which cuts a circular chunk of flesh out of its victim and then moves on.

But there have been a couple of relatively recent discoveries that demonstrate that the world is not only stranger than we imagine, it’s often stranger than we can imagine.

The most recent, discovered in 2012, is the carnivorous harp sponge, a beautiful little critter that clings to the ocean floor 10,000 feet below the surface, and puts up delicate fans covered in velcro-like hooks to snag tiny crustaceae, which it then proceeds to digest. Slowly.

An earlier discovery is the ping pong tree sponge. It too is beautiful, as you can see from the picture on this page, although you might want to avoid reading too far below the images, because the graphic description of how the tiny creature consumes its prey is enough to put you off your lunch.

As I mentioned in the earlier post about the goblin shark, these monsters of the deep can survive for geological ages because the deep ocean is a fairly changeless environment. There are no seasons, no periodic tidal exposure or deluge, and this stability means that there are fewer selection pressures, so once a species has established a foothold in the ecosystem, there’s nothing driving it to change further.

And I can’t finish a post on deep sea critters without mentioning the dumbo octopus. While not striking fear into any heart but that of their prey, these creatures illustrate yet again the multiplicity of life that lurks on, or near, the sea floor. Anyone fancy a swim?

[Featured image: Dumbo octopus. Image courtesy the NOAA Office of Ocean Exploration and Research, Exploration of the Gulf of Mexico 2014. In the public domain]