Sea spiders move oxygen with pumping guts (not hearts)

Date:  July 10, 2017

Source:  Cell Press

Summary:  To keep blood and oxygen flowing throughout their bodies, most animals depend on a beating heart. But researchers have discovered that sea spiders use a strange alternative: they move blood and oxygen throughout most of their bodies by pumping their guts. The sea spiders have an unusual gut in the first place, the researchers say.

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Honeybees Harbor Antibiotic-Resistance Genes

ScienceDaily (Oct. 30, 2012) — Bacteria in the guts of honeybees are highly resistant to the antibiotic tetracycline, probably as a result of decades of preventive antibiotic use in domesticated hives. Researchers from Yale University identified eight different tetracycline resistance genes among U.S. honeybees that were exposed to the antibiotic, but the genes were largely absent in bees from countries where such antibiotic use is banned.

The study appears on October 30 inmBio®, the online open-access journal of the American Society for Microbiology.

"It [resistance] seems to be everywhere in the U.S.," says Nancy Moran of Yale University, a senior author on the study. "There's a pattern here, where the U.S. has these genes and the others don't."

Honeybees the world over are susceptible to the bacterial disease called "foulbrood," which can wipe out a hive faster than beekeepers can react to the infection. In the U.S., beekeepers have kept the disease at bay with regular preventive applications of the antibiotic oxytetracycline, a compound that closely resembles tetracycline, which is commonly used in humans. Oxytetracycline has been in use among beekeepers since the 1950s, and many genes that confer resistance to oxytetracycline also confer resistance to tetracycline.

Continued:  http://www.sciencedaily.com/releases/2012/10/121030062405.htm

Dinosaur Guts Reveal Velociraptor's Last Meal

A lightweight Velociraptor dinosaur may have chowed down on the carcass of a much larger flying reptile not long before meeting his own demise some 75 million years ago.

The evidence comes from a pterosaur bone discovered in the gut of the skeletal remains of what was likely aVelociraptor mongoliensis that lived in what is now the Gobi Desert in Mongolia. The fossil, the first pterosaur bone to be found inside dinosaur guts, was discovered in 1994 but not fully analyzed and detailed in a scientific publication until now.

Velociraptor was known to have fearsome sickle-shaped talons on the second toe of each foot; it kept these talons off the ground like foldable switchblades. Past research has shown these theropod dinosaurs used their talons to slash live prey and hook them to keep them from escaping.

The new study, which says the pterosaur may have been dead before the predator found it, adds to research suggesting the fierce carnivores wouldn't turn their back on a free meal, either. A study published in 2010 reported the discovery of a Velociraptor frozen in time, scavenging the corpse of a larger dinosaur.

Read on:  http://www.livescience.com/18855-velociraptor-gut-contents.html

Salmon and Other Fish Predators Rely On 'No Guts, No Glory' Survival Tactic

ScienceDaily (Sep. 15, 2011) — The phrase "no guts, no glory" doesn't just apply to athletes who are striving to excel. Salmon and other fish predators take the adage literally, by having up to three times the "gut" capacity they need on a daily basis just so they can "glory" when prey is abundant, University of Washington researchers have discovered.

It's a previously unrecognized survival tactic that might apply to other top predators, such as wolves, lions and bears, according to Jonathan Armstrong, a UW doctoral student in aquatic and fishery sciences and lead author of a letter published recently in the journal Nature.

"The predatory fish we examined have the guts to consume two- to three-times the amount of food that they regularly encounter. This much excess capacity suggests predator-prey encounters are far patchier -- or random -- than assumed in biology and that binge-feeding enables predators to survive despite regular periods of famine," Armstrong said. Co-author on the paper is Daniel Schindler, UW professor of aquatic and fishery sciences.

"Guts are really expensive organs in terms of metabolism," Armstrong said. For instance, maintaining a gut can require 30 to 40 percent of the blood pumped by an animal's heart.

Some animals have some capacity to grow or shrink their guts in response to changing conditions. For example, the digestive organs of birds that are about to migrate expand so they can eat more and fatten up. This is followed by a period when their guts atrophy and then, freed of the baggage of heavy guts, the birds take off.

That and results from lab studies led some scientists to assume that predators eliminate excess digestive capacity to save energy in times of famine. But the UW findings show that many fish species maintain a huge gut, which enables them to capitalize on unpredictable pulses of food.

"For predator fish, the world is a slot machine -- sometimes they stumble upon small meals and other times they hit the jackpot. It's just not as predictable as some have thought," Armstrong said.

"Unlike some other animals, fish can't just hoard their food behind a rock in the stream and eat it later. They need to binge during the good times so that they can grow and build energy reserves to survive the bad times."

Armstrong and Schindler hope that their results can help with ecological models used in conservation and management.

"Ecosystem models typically assume relatively constant interactions between predator and prey but our results suggest such interactions are extremely patchy. We're excited to see if including this ecological realism might improve the predictions of these models."

The work was funded by the UW School of Aquatic and Fishery Sciences, National Science Foundation and the Gordon and Betty Moore Foundation.
http://www.sciencedaily.com/releases/2011/09/110915141237.htm