Life

Jellyfish keep eyes on the sky, plus hot mosquitoes, the key to royal jelly and more in this week’s news

Eyes on the skies
Even though box jellyfish don’t rank very high on visual tasks, they may be able to navigate underwater by picking up cues from above the water. One of the four types of the 24 eyes of Tripedalia cystophora is positioned on a stalk that keeps the simple, image-forming organs looking up regardless of which way the jelly is swimming. Upward eyes monitoring for forest canopy could allow the animals to swim into favorable habitat under a mangrove tree. Navigation benefits might help explain the evolution of such elaborate visual equipment among creatures that don’t seem to do a lot that demands detailed images, suggests an international research team in the May 10 Current Biology. —Susan Milius

LOOK UP A box jellyfish may be using one of the four types of its 24 eyes to check for mangrove branches above as a signal of good habitat. Courtesy of Anders Garm and Jan Bielecki

Cloudy with a chance of bass
Adding largemouth bass to a previously bass-free lake reveals subtle warning signs that ripple through a freshwater ecosystem well before a new invasive predator reconfigures the local food web. To monitor such a takeover, a team of ecologists gradually added largemouth bass to a lake dominated by a variety of fish that feed on the tiny plankton awash in water. The bassification process stretched over three years, but after only two, the lake water itself had already started to change, for example with increasingly high variability in concentrations of light-capturing microbes. Knowing what to look for might someday help spot ecosystem regime shifts on the horizon, researchers report in the April 29 Science. —Susan Milius

The bee that would be queen
Murder made Lady Macbeth queen — bees just have to eat jelly. A new study identifies the main ingredient at play in honeybees’ royal jelly, the decadent nectar that turns regular larvae into queen bees. It’s royalactin, Masaki Kamakura of the Toyama Prefectural University in Japan reports online April 24 in Nature. This coronation chemical seems to flip on insect enzymes that make larvae grow faster and quicker as well as develop more mature ovaries than normal bees. Bugs deprived of royalactin grow into worker bees, which, in a twist that would catch Marx’s eye, produce the royal jelly that would-be queens eat. —Daniel Strain

Hot meal stresses mosquitoes
A hot spurt of blood is surely one of a mosquito’s favorite things, but eating a hot meal can be stressful. Imbibing blood caused a female mosquito’s body temperature to shoot up 10 degrees Celsius in a minute, researchers at Yale, Ohio State University and the University of Florida report online April 25 in the Proceedings of the National Academy of Sciences. The mosquitoes deal with the hot flash by making more of a heat shock protein — a protein that helps protect other proteins from damage. Reducing levels of the heat shock protein in the insects’ guts interfered with digestion and caused the mosquitoes to lay fewer eggs. —Tina Hesman Saey

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