Study reveals mechanism behind squids’ and octopuses’ ability to change color

This shows the diffusion of the neurotransmitter applied to squid skin at upper right, which induces a wave of iridescence traveling to the lower left and progressing from red to blue. Each object in the image is a living cell, 10 microns long; the dark object in the center of each cell is the cell nucleus. Credit: UCSB

Color in living organisms can be formed two ways: pigmentation or anatomical structure. Structural colors arise from the physical interaction of light with biological nanostructures. A wide range of organisms possess this ability, but the biological mechanisms underlying the process have been poorly understood.

Two years ago, an interdisciplinary team from UC Santa Barbara discovered the mechanism by which a neurotransmitter dramatically changes color in the common market squid, Doryteuthis opalescens. That neurotransmitter, acetylcholine, sets in motion a cascade of events that culminate in the addition of phosphate groups to a family of unique proteins called reflectins. This process allows the proteins to condense, driving the animal’s color-changing process.

Now the researchers have delved deeper to uncover the mechanism responsible for the dramatic changes in color used by such creatures as squids and octopuses. The findings –– published in the Proceedings of the National Academy of Science, in a paper by molecular biology graduate student and lead author Daniel DeMartini and co-authors Daniel V. Krogstad and Daniel E. Morse –– are featured in the current issue of The Scientist.

Read the full article here.

People who eat more fish live 2.2 years longer, say latest results from Harvard health study

The July Tufts Health Newsletter highlights the latest results from the long running Harvard public health study. According to Dr. Dariush Mozaffarian, the new results were among the first to look at the relationship of Omega-3 levels in the blood stream and overall mortality of older adults.

“The advantages of eating fish are many,” says Alice H. Lichtenstein, DSc, director of Tufts’ HNRCA Cardiovascular Nutrition Laboratory. “Fish offers omega3 fatty acids and, depending on how it is prepared, is low in calories and saturated fat.” Besides the inherent nutritional positives of fish, she adds, substituting fish (not fried or heavily breaded) for entrées such as steak and quiche pays off doubly.

The American Heart Association recommends eating fish at least twice a week, particularly fatty varieties high in omega-3s such as salmon, mackerel, herring, lake trout, sardines and albacore tuna. A “serving” is 3.5 ounces cooked, or about three-quarter cup of flaked fish.

Now there’s fresh evidence that following that advice can not only reduce your risk of cardiovascular disease, but actually help you live longer—especially if you’re already age 65 or older. “Although eating fish has long been considered part of a healthy diet, few studies have assessed blood omega-3 levels and total deaths in older adults,” says Dariush Mozaffarian, MD, PhD, of the Harvard School of Public Health. New findings by Dr. Mozaffarian and colleagues published in Annals of Internal Medicine, he says, “support the importance of adequate blood omega-3 levels for cardiovascular health, and suggest that later in life these benefits could actually extend the years of remaining life.”

The researchers examined 16 years of data from about 2,700 US adults age 65 or older who participated in the long-term Cardiovascular Health Study. Participants, average age 74, were generally healthy and did not take fishoil pills. Rather than relying on dietary questionnaires to measure fish consumption, the study took blood samples at baseline to analyze total omega-3s as well as levels of three specific omega-3s found in fish: DHA (docosahexaenoic acid), EPA (eicosapentaenoic acid) and DPA (docosapentaenoic acid).

Overall, study participants with the highest total omega-3 levels had a 27% lower risk of total mortality due to all causes, and in particular were less likely to die of coronary heart disease and arrhythmia. Those with the most blood omega-3s lived, on average, 2.2 years longer than those with the lowest levels.

Read the full story here.

Voyage to study effects of ocean acidification off U.S. West Coast

Scientists aboard the survey ship Fairweather will travel along the U.S. West Coast to study ocean acidification. (National Oceanic and Atmospheric Administration / July 25, 2013)

A team of scientists is setting out on a research expedition along the U.S. West Coast to study ocean acidification, the greenhouse gas-driven change in the chemistry of seawater that has been called climate change’s “evil twin.”

Chemists and biologists from the National Oceanic and Atmospheric Administration will board the survey ship Fairweather next week, sailing from Canada to Mexico to collect samples of water, algae and plankton, officials said Thursday. The goal of the monthlong voyage is to better understand how marine ecosystems are responding to water that is becoming more acidic as a result of the buildup of carbon dioxide in the atmosphere.

“We will for the first time not only study the chemistry of acidification but also study at the same time the biological impacts,” Richard Feely, an oceanographer with NOAA’s Pacific Marine Environmental Research Laboratory, told reporters in a telephone briefing.

Oceans have absorbed about 25% of the greenhouse gases that have accumulated in the atmosphere from the burning of fossil fuels, buffering some of the effects of climate change, Feely said. But that comes at a great cost to marine life because when carbon dioxide dissolves in seawater, it lowers itsthe water’s. The gradual change in chemistry poses a particular threat to shellfish such as oysters and clams that require alkaline water to build their protective shells.

The research expedition could shed light on whether acidification is harming pteropods, marine snails that are especially sensitive to changing acidity and are a key food source for fish, birds and whales. Scientists also want to know whether acidification is making harmful algae blooms more toxic to marine life. Increased toxicity has been shown in laboratory experiments but not observed the field.

Read the full story here.

Huffman introduces bill to refinance decade-old fishing industry loan

Legislation aimed at alleviating the financial hardship of a federal loan that has been weighing on Pacific Coast groundfish fisherman for nearly a decade has moved one step closer to passing, North Coast Congressman Jared Huffman’s office announced on Thursday.

Introduced into Congress this week, Huffman’s “Revitalizing the Economy of Fisheries in the Pacific Act” picks up where a bipartisan bill introduced in September 2012 by former North Coast Congressman Mike Thompson left off, and would allow for the refinancing of a $35.7 million buyback loan authorized by Congress in 2003.

In a press release, Huffman called the bill — his second piece of legislation to be introduced since he took office in January — “… a win-win for small businesses and the environment.”

The opportunity to refinance the loan at a lower interest rate would give local groundfish fishermen the same opportunities as any homeowner or business, and would not require the federal government to spend any new money.

“The success of our local fishermen is essential to the health of the North Coast’s economy, but it is becoming increasingly difficult for them to repay the debt on a decade-old federal loan,” Huffman said in the release. “The combination of interest payments, new fees, and rising fuel costs are putting small businesses in our coastal communities at risk.”

Read the full story here.

‘Dancing Squid’ Phenomenon: How Soy Sauce Brings A Dead Creature Back To ‘Life’

Soy sauce may be able to revive a dull dish, but it hardly has the ability bring dead things back to life. Yet, that’s exactly what the condiment appears to do in a GIF recently posted on Reddit.

Borrowed from a 2010 Youtube video, the GIF shows a cuttlefish seemingly coming back to life when soy sauce is poured atop it. The cephalopod’s body lifts up and writhes in the bowl, prompting viewers to ask: Is it really dead?

Indeed, the cuttlefish in the video — part of a seafood dish named odori-don — is no longer living. The cuisine, sometimes prepared with squid and known as the “dancing squid rice bowl,” rose to prominence after Japanese sushi restaurant Ikkatei Tabiji began preparing the plate in this particular fashion, according to CBS News.

So how does the squid “come back to life?”

Read full story here.

http://youtu.be/iqphVlp2VJI

Agency says Pacific great white shark not in danger of extinction

A great white shark plies waters at Guadalupe Island in 2007. (Al Seib / Los Angeles Times / November 15, 2007)

The National Oceanic and Atmospheric Administration announced Friday that the northeastern Pacific Ocean population of great white sharks is not in danger of extinction and does not warrant listing under the Endangered Species Act.

NOAA had been researching the health of the great white population since last year, when the environmental groups Oceana, Shark Stewards and the Center for Biological Diversity filed a petition calling for endangered species protection.

The petitioners were reacting to the first census of great whites ever attempted. Conducted by UC Davis and Stanford University researchers, and published in the journal Biology Letters in 2011, the census estimated that only

219 adult and sub-adult great whites lived off the Central California coast, and perhaps double that many were in the entire northeastern Pacific Ocean, including Southern California.

Read the full story here.

Oxford University reveal that a fishy diet can improve reading and concentration in kids

Omega-3 fatty acids called EPA and DHA, found in fish and seafood, are essential for the brain’s structure and function as well as for maintaining a healthy heart.

Research carried out at Oxford University and published in the journal PLOS One, found children’s blood levels of DHA “significantly predicted” how well they were able to concentrate and learn.

Blood omega-3 levels were studied in 493 UK schoolchildren aged from seven to nine.

Read the full story here.