SNIPPETS

Monsters that dine on slime

What do monsters eat? No one knew in the case of vampyroteuthis infernalis – the vampire squid from hell. With its blue eyes, dark red body and cloaklike webbing over its arms, experts assumed the worst, that, like its cousins the squids and the octopuses, it enjoyed dining on live prey. Although found in the depths of all the world’s oceans, the creature lived in a twilight zone that few other animals could inhabit because the levels of dissolved oxygen were so low.

Marine biologists at the Monterey Bay Aquarium Research Institute in California have  pointed out that the monster dines on slime. Hendrik J T Hoving, a postdoctoral fellow, and Bruce H Robison, a senior scientist, report that the vampire squid extends two threadlike filaments like fishing lines to capture organic debris. The sticky lines are up to eight times the length of the body. Oceanographers refer to the flaky debris as ‘marine snow’. It is composed of decaying bodies, microscopic algae and slimy goo from gelatinous animals that use mucus nets to gather food.

Hoving and Robison, writing in The Proceedings of the Royal Society B: Biological Sciences, say they looked at museum collections of vampire squids to examine stomach contents. They examined videos of the animals in their deep environment. They used robots to collect live squid and study their feeding habits in the laboratory. Finally, they used microscopes to examine the creature’s arms and feeding filaments. It thrives by inhabiting a hostile environment where “predators are few, and its food is abundant.”

William J Broad
New York Times News Service


Smooth flight in reverse

It would seem to take a lot of energy for a bird to move backward, but hummingbirds fly in reverse fairly often. Now a study reports that their backward flight is almost as efficient as their forward flight. “When they are flying backwards they have a very upright body posture,” said Nir Sapir, an avian ecologist affiliated with the Max Planck Institute for Ornithology in Germany and one of the researchers involved in the study. “We thought they might have a much higher drag and invest much more energy in flight.”

Sapir worked on the study when he was a postdoctoral researcher at the University of California, Berkeley. He and his colleague Robert Dudley, a researcher at the Smithsonian Tropical Research Institute in Panama, reported their findings in The Journal of Experimental Biology. Sapir captured five Anna’s hummingbirds outside his laboratory and trained them to fly in a wind tunnel and feed on a syringe of sucrose disguised as a flower. As they fed, Sapir turned on the air in the tunnel so that the birds had to fly backward to remain at the flower. He repeated the experiment with the feeder rotated 180 degrees so that the birds had to fly forward to keep feeding. When flying forward, the birds beat their wings about 39.7 hertz. When they flew backward, they beat their wings only slightly faster, at 43.8 hertz. The rate of oxygen consumption was also similar, Sapir said.

Sindya N Bhanoo
New York Times News Service

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