MBARI researchers discover what vampire squids eat (it's not what you think)

(Not LBN, but I thought it was interesting and hadn't seen it before.)

About 100 years ago, marine biologists hauled the first vampire squid up from the depths of the sea. Since that time, perhaps a dozen scientific papers have been published on this mysterious animal, but no one has been able to figure out exactly what it eats. A new paper by MBARI Postdoctoral Fellow Henk-Jan Hoving and Senior Scientist Bruce Robison shows for the first time that, unlike its relatives the octopuses and squids, which eat live prey, the vampire squid uses two thread-like filaments to capture bits of organic debris that sink down from the ocean surface into the deep sea.
It's easy to imagine the vampire squid as a nightmarish predator. It lurks in the eternal midnight of the deep sea, has a dark red body, huge blue eyes, and a cloak-like web that stretches between its eight arms. When threatened, it turns inside out, exposing rows of wicked-looking "cirri." Even its scientific name, Vampyroteuthis infernalis, means "vampire squid from hell."

In reality, the vampire squid is a soft-bodied, passive creature, about the size, shape, and color of a football. A "living fossil," it inhabits the deep waters of all the world's ocean basins at depths where there is almost no oxygen, but also relatively few predators.

A few previous researchers have caught vampire squids in nets, hauled them up to the surface, and tried to figure out what they ate by examining the contents of their stomachs. The results were generally inconclusive. The stomachs typically contained bits and pieces of tiny, shrimp-like animals, microscopic algae, and lots of slimy goo.

In a recent article in the Proceedings of the Royal Society B: Biological Sciences, Hoving and Robison show that vampire squids eat mostly "marine snow"—a mixture of dead bodies, poop, and snot. The dead bodies are the remains of microscopic algae and animals that live in the waters farther up in the ocean, but sink down into the depths after they die. The poop consists of fecal pellets from small, shrimp-like animals such as copepods or krill. The snot is mostly debris from gelatinous animals called larvaceans, which filter and consume marine snow using mucus nets.

In addition to looking at the stomach-contents of vampire squids from museum collections, the researchers used MBARI's remotely operated vehicles (ROVs) to collect live vampire squids and study their feeding habits in the laboratory. They also examined high-definition videos of vampire squids taken by MBARI's ROVs. Finally, they examined vampire squid arms and feeding filaments under optical and scanning electron microscopes.
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more: http://www.mbari.org/news/news_releases/2012/vampfood/vampfood-release.html




There is an extended video of a vampire squid swimming and feeding.