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Why We Need to Save the Burnt Hot Dog Sea Cucumber

Holothuria edulis is better known as the burnt hot dog sea cucumber. Besides having a terrific name, this creature is fascinating—one that scientists insist is an underrated but valuable member of ocean ecosystems. A team of researchers recently published a report on the sea cucumber and its importance in the journal Conservation Genetics.

Like all sea cucumbers, H. edulis is essentially a squishy tube with a mouth at one end and an anus at the other. It rests during the day and emerges to hunt at night, using its little tentacles to shove seafloor garbage and sediment into its mouth. It then poops out clean, freshly oxygenated sand. Think of it as the ocean's very own carpet steamer. Also much like other sea cucumbers, when H. edulis feels threatened, it can literally puke its guts out, ejecting its organs into the surrounding water.

Believe it or not, H. edulis and some of its relatives sometimes have a hard time finding mates or ideal mating conditions. Fortunately, they’ve got a backup plan: asexual reproduction.

The problem with solo baby-making is that it effectively dries up the gene pool. An increase in asexual reproduction (the most concentrated form of inbreeding) means a decrease in genetic diversity, which is bad for the species' long-term prospects.

Reduced genetic diversity in animals like sea cucumbers may indicate that they’ve started going it alone. Previous studies have shown that other sea cucumber species are more likely to reproduce asexually in contaminated waters. Because of this, a sea cucumber’s genes can tell biologists a lot about how the animals and their environment are doing.

These days, unfortunately, many sea cucumbers are not doing so well. Ocean pollution and habitat destruction are shrinking available safe space. Sea cucumbers are also valued as both food and medicine in some parts of the world, and some of those areas have only recently implemented regulations to prevent overfishing.

Dried sea cucumbers for sale in Hong Kong. Image Credit: © Steve Taylor

One such area is Okinawa, Japan, home to our friend the burnt hot dog sea cucumber. To check up on H. edulis populations, a team of scientists dove to find them at six points around the main island. The researchers then just snipped a small bit of tissue from each animal’s outer body wall before returning it to its home. Back on land, the researchers sequenced each animal’s DNA and compared the results.

"The data tell a story," study co-author Iria Fernandez-Silva said in a press statement. "We saw low genetic diversity in some sea cucumber populations along Okinawa's eastern coastline, where water is polluted by nearby industry, runoff, and coastal development. In contrast, populations in more pristine sites on the island's west coast were more genetically diverse. Since populations appeared disconnected from one another, we can predict that overfishing might be the last straw for vulnerable sea cucumber populations ill-equipped for a comeback."

Why does this matter? Think back to H. edulis's nighttime seafloor cleanups and their role as the ocean's carpet steamer.

"It's easy to underestimate the sea cucumber," Fernandez-Silva said. "Sea cucumbers look goofy, move slowly, and barf up their guts when startled, but these invertebrates are superstar ocean cleaners that are hugely important to marine ecosystems.”

Fernandez-Silva and her colleagues say it’s up to Japan to set an example of good marine stewardship. Tighter environmental and fishing restrictions may be the only way to preserve this vital part of the ecosystem.

"Where ocean life is concerned, looks aren't everything," says Fernandez-Silva. "We urge global communities to speak up in defense of important marine species, even those that look like burned hot dogs.”

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Courtesy of The National Aviary
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Animals
Watch This Live Stream to See Two Rare Penguin Chicks Hatch From Their Eggs
Courtesy of The National Aviary
Courtesy of The National Aviary

Bringing an African penguin chick into the world is an involved process, with both penguin parents taking turns incubating the egg. Now, over a month since they were laid, two penguin eggs at the National Aviary in Pittsburgh, Pennsylvania are ready to hatch. As Gizmodo reports, the baby birds will make their grand debut live for the world to see on the zoo's website.

The live stream follows couple Sidney and Bette in their nest, waiting for their young to emerge. The first egg was laid November 7 and is expected to hatch between December 14 and 18. The second, laid November 11, should hatch between December 18 and 22.

"We are thrilled to give the public this inside view of the arrival of these rare chicks," National Aviary executive director Cheryl Tracy said in a statement. "This is an important opportunity to raise awareness of a critically endangered species that is in rapid decline in the wild, and to learn about the work that the National Aviary is doing to care for and propagate African penguins."

African penguins are endangered, with less than 25,000 pairs left in the wild today. The National Aviary, the only independent indoor nonprofit aviary in the U.S., works to conserve threatened populations and raise awareness of them with bird breeding programs and educational campaigns.

After Sidney and Bette's new chicks are born, they will care for them in the nest for their first three weeks of life. The two penguins are parenting pros at this point: The monogamous couple has already hatched and raised three sets of chicks together.

[h/t Gizmodo]

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holidays
Bleat Along to Classic Holiday Tunes With This Goat Christmas Album
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iStock

Feeling a little Grinchy this month? The Sweden branch of ActionAid, an international charity dedicated to fighting global poverty, wants to goat—errr ... goad—you into the Christmas spirit with their animal-focused holiday album: All I Want for Christmas is a Goat.

Fittingly, it features the shriek-filled vocal stylings of a group of festive farm animals bleating out classics like “Jingle Bells,” “Rudolph the Red-Nosed Reindeer,” and “O Come All Ye Faithful.” The recording may sound like a silly novelty release, but there's a serious cause behind it: It’s intended to remind listeners how the animals benefit impoverished communities. Goats can live in arid nations that are too dry for farming, and they provide their owners with milk and wool. In fact, the only thing they can't seem to do is, well, sing. 

You can purchase All I Want for Christmas is a Goat on iTunes and Spotify, or listen to a few songs from its eight-track selection below.

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