Iridescent beetles, jet-propelled nautiluses and “walking cactus”

The secret to the Japanese jewel beetle’s shine is layers of chitin, threats to the ancient nautilus, a “walking cactus” provides a link between worm and insect, researchers propose drying out Australia’s cane toads, macaques display awareness of their own uncertainty and Florida’s alligator mating season is close at hand. Here is research in ecology and beyond from the last week in February. Iridescent beetle: A study recently published in The Philosophical Transactions of the Royal Society Biological Sciences explored the stacked chitin layers on the body and wings of the Japanese jewel beetle (Chrysochroa fulgidissima). Danielle Venton described the beetle in a Wired Science article: “[S]urface ridges cause visible iridescence, but their primary job is to deflect water or mud. Many are active at night, when their colors can’t be seen. But the Japanese jewel beetle’s surface is smooth, and the study’s authors suspect that iridescence helps these insects recognize each other and find mates.” Read more and see photos at “Gorgeous Jeweled Beetle Reveals Its Tricks.” Jet-propelled nautilus: In the online Scientific American column “Zoologger,” Michael Marshall described the Nautilus pompilius, a shelled cephalopod found in the Indo-Pacific: “Nautiluses mostly scavenge for dead crustaceans, worms and starfish, often digging for them in mud and biting into them with their sharp beaks. They hunt mostly by smell, tracking odours from up to 10 metres away.” This species could be at risk of a severe population decline, said Marshall, due to their slow reproduction rate. Read more at “Jet-propelled living fossil with a problem.” Walking cactus: Jianna Liu from Northwest University in China and colleagues have found the fossil of Diania cactiformis, an organism dubbed the “walking cactus” that may have been related to the velvet worm. “The creature, which dates from around 500 million years ago, is about 6 centimetres long,” wrote Zoë Corbyn in a Nature News article. “It resembles a thin, soft-bodied worm, similar to the lobopodians. But it is also arthropod-like in that it has jointed legs—ten pairs in total. The researchers believe the legs had hardened surfaces, not unlike the tough surfaces of the articulated limbs of crustaceans or insects.’” Read more at “‘Walking cactus’ is anthropods’ lost relative.” Aussie invasions: Researchers are exploring ways of reducing Australia’s cane toad population by drying out the rapidly breeding nonnative pests. As Ed Yong explained in Not Exactly Rocket Science, “While some frogs burrow underground or create protective cocoons, cane toads simply lose water until they die of dehydration. In the heat of Australia’s dry season, they need bodies of water to survive. Fortunately for them, humans have provided them with moisture galore, in the form of...

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It takes more than climate change to cause amphibian decline

This post contributed by Monica Kanojia, Administrative Assistant/Governance for ESA. Amphibians have been around for hundreds of millions of years. They have survived numerous extinction events and yet somehow, in the past two decades, their numbers have been in severe decline. The population changes have been linked to many factors, including climate change and disease, habitat destruction and water pollution. Studies indicate that amphibians are sensitive to all of the proposed variables—not just one root cause. A unique quality of amphibian biology is their transdermal water uptake ability. Transdermal uptake allows for nutrients to be delivered across the skin. For example, the skin of a frog allows for the direct exchange of oxygen, carbon dioxide and water from the environment. While in ideal situations this would be beneficial, it currently poses a threat to amphibian populations. Overexposure to any nutrient can be lethal to an organism. With increased rates of carbon dioxide in the atmosphere, heavily polluted water and loss of water, amphibians’ ability to survive is diminishing. A majority of amphibian species go through reproductive and developmental stages that require a body of water. The eggs of amphibians are not as resilient as reptile or bird eggs because they are jelly coated and unsuitable for development on land; therefore, amphibians must return to water to reproduce. Increased agricultural and industrial run off and poor waste management has led to a decline in the quality of water available for amphibians. The main types of chemical contaminants affecting amphibian environments are pesticides and herbicides, heavy metals, increasingly acidic water and nitrogen pollution. According to a study published in the journal Environmental Health Perspectives by Tyrone Hayes from the University of California, Berkeley and colleagues, pesticides commonly used in cornfields in the western United States have adverse affects on amphibian larval growth and development, immune system and the size prior to and after metamorphosis. High levels of pesticides enter streams and groundwater as water runs off of farms, ranches, golf courses and suburban areas. While organic and low-risk pesticide use is encouraged by the U.S. Environmental Protection Agency, it remains predominantly unregulated… That is, the EPA lists guidelines for how to safely use pesticides for commercial and agricultural needs, but it does not strictly regulate what can and cannot be used. Herbicides, on the other hand, are made to disrupt photosynthesis capabilities of plants and were thought to have little to no effect on fish and wildlife.  But, as Science Daily reported in 2008, studies have revealed otherwise. For example, atrazine—one of the most commonly used herbicides on golf courses, home lawns and soybean and corn crops—is responsible for lethal changes...

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Mites and poor diet contribute to honeybee decline in Europe

Two timely reports have surfaced this week regarding the decline of honeybee populations in Europe, and France has taken action in an attempt to curb the falling numbers.  A recent study linked honeybee health and plant biodiversity In a study published in the Journal of Apicultural Research, scientists have found that managed honeybee populations across Europe have dropped an average of 20 percent over the last 20 years, with England being hit the hardest at a 54 percent decline. Simon Potts and colleagues from the University of Reading analyzed several patterns across 18 countries in Europe and found the mite Varroa destructor–a parasite responsible for transmitting infections in honeybee colonies—infested virtually every honeybee colony they examined. In another study, scientists from the French National Institute for Agricultural Research (INRA) in Avignon reported a possible dietary connection between the strength of the honeybee immune system and plant biodiversity.  Cedric Alaux, who co-authored the study published in Biology Letters, told BBC News:    We found that bees fed with a mix of five different pollens had higher levels of glucose oxidase compared to bees fed with pollen from one single type of flower, even if that single flower had a higher protein content.  Bees use glucose oxidase to sterilize colony and brood food in an effort to make the hive resistant to infection. As Alaux told BBC, a more diverse diet, therefore, might help a honeybee colony protect against pathogen invasion.   These studies emerge amidst France’s recent decision to sow nectar-bearing flowers alongside 250 kilometers (155 miles) of roadway in an effort to boost honeybee populations. If the results from the three-year test are positive, France is prepared to extend the flowers along the country’s 12,000-kilometer (7,500-mile) network of non-toll roads.  Read more at BBC and the Telegraph.    Photo Credit: http://www.flickr.com/photos/aussiegall/ / CC BY 2.0 Potts, S., Settele, J., Neumann,, P., Jones, R., Mike A Brown, M., Marris, G., Dean, R., & Roberts, S. (2010). Declines of managed honey bees and beekeepers in Europe Journal of Apicultural Research, 49 (1) DOI:...

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