Life Sciences

A Tiny Jellyfish Relative Just Shut Down Yellowstone River

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Yellowstone River in Hayden Valley. Yellowstone National Park, Wyoming, USA Photo: Ed Austin/Herb Jones, US National Park Service, 1987

The parasite has devastated the whitefish population and is now threatening the trout.

On August 12, Montana officials realized that the mountain whitefish of Yellowstone River were dying en masse. They sent corpses off for testing and got grave news in return: The fish had proliferative kidney disease—the work of a highly contagious parasite that kills between 20 and 100 percent of infected hosts. Tens of thousands of whitefish were already dead, and trout were starting to fall.

Humans can spread the parasite from one water source to another. So, on the morning of August 19, Montana Fish, Wildlife and Parks closed a 183-mile stretch of the Yellowstone River, banning all fishing, swimming, floating, and boating. “We recognize that this decision will have a significant impact on many people,” said FWP Director Jeff Hagener in a press release. However, we must act to protect this public resource for present and future generations.”

The press statement and all the subsequent news reports referred to the organism behind the fishes’ woes as a “microscopic parasite.” A few select outlets actually named the thing—Tetracapsuloides bryosalmonae. But none of them realized how extraordinary it really is.

It is part of a group called the myxozoans. They spend most of their lives as microscopic spores that are made of just a few cells. Despite their appearances, these creatures are animals. And although they are obscure, you have definitely heard of their closest relatives—jellyfish, corals, and sea anemones. Yellowstone River is now closed because more than half a billion years ago, a jellyfish-like animal started transforming into a parasite.

Marine Biologists Find Rare Nautilus For The First Time In 30 Years

(Peter Ward)
(Peter Ward)

The “Crusty Nautilus” was believed to have gone extinct.

Last month, Biologist Peter Ward was on an exploratory trip off the coast of Ndrova Island in Papua New Guinea, when he saw something he hadn’t seen since 1986: a specimen of Allonautilus scrobiculatus, otherwise known as the crusty nautilus.

Before the crusty nautilus made its reappearance in July, only two humans had ever reported seeing it: Ward and his colleague, Bruce Saunders. But ever since, the animal has eluded searchers and many marine biologists feared that it had gone extinct. Ward returned to where he and Saunders first found the mollusc to see if any had survived being hunted for their shells and ongoing environmental change.

Because nautili have a narrow band of cold temperatures where they can live, Ward and his team brought several captured specimens to the surface in cold water, where they took samples before releasing them at the capture point, according to Sci-News.com. The molluscs, which are distantly related to squid and cuttlefish, are commonly called “living fossils” because their shells have been found dating back 500 million years in the fossil record. While they are one of the oldest species on the planet, they are threatened by “nautilus miners” who hunt and kill them to sell their shells as souvenirs, Urton writes.

Enterovirus 68 May Be Linked to Paralysis in Children, Study Sa

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A 4-year-old boy with partial paralysis received physical therapy in October at Spaulding Rehabilitation Hospital in Charlestown, Mass.

A new strain of a common respiratory virus may be responsible for partly paralyzing scores of children nationwide, researchers reported on Monday.

Since August, 115 children in 34 states have developed polio-like paralysis in an arm or a leg. The virus, enterovirus 68, has emerged as a leading suspect.

A study published Monday in the journal Lancet Infectious Diseases strengthens that possibility, although many questions remain.

Researchers at the University of California, San Francisco, analyzed genetic sequences of enterovirus 68 cultured from 25 children in Colorado and California with limb paralysis, also called acute flaccid myelitis.

The viruses were genetically very similar, the scientists found, sharing certain mutations that resemble those found in the poliovirus genome.

The researchers concluded that the viruses were a novel strain of enterovirus 68, which they called B1. Using a method called “molecular clock analysis,” the team estimated that the B1 strain emerged about four and half years ago.

“I don’t think it’s coincidental that it’s around the time the first cases were described,” said Dr. Charles Chiu, the study’s senior author and an associate professor of laboratory medicine at University of California, San Francisco.

Love hurts? Sea slug amputates own penis after sex, study finds

The red-and-white sea slug Chromodoris reticulata sheds its own penis after mating, a new study shows. (Stephen Childs / Flickr.com)

The band King Missile’s 1992 single “Detachable Penis” might seem like a tripped-out nightmare straight from the male psyche, but it’s all too real for one strange sea creature. The sea slug Chromodoris reticulata has a disposable penis that it sheds after sexual intercourse, according to a new study in the journal Biology Letters.

Researchers in Japan collected the red-and-white sea slug in shallow coral reefs off the coast of Okinawa. They stuck pairs of sea slugs in a small tank and watched the critters mate, documenting what they rather aptly called “bizarre mating behavior.”

C. reticulata is a hermaphrodite: Each animal possesses both male and female reproductive organs, and can use both at the same time. So in 31 trysts, the researchers watched the sea slugs line up head-to-toe (so to speak) and jab their long, thin penises into their partners’ vaginas, while simultaneously receiving their partners’ sperm. The trysts lasted anywhere from tens of seconds to several minutes. A few minutes after it ended, the sea slugs each dropped their penises.

Part of the penis is stored in a spiral inside the body, and once the sea slugs discarded the used part of their members, the undifferentiated tissue in the spiral would develop into a usable organ again. About 24 hours after copulating, they’d be ready for another round.

The sea slugs appeared to have enough penis for at least three chances to inseminate a partner, the authors noted.

When the researchers examined the detached penises, they found that the surface was covered in backwards-facing barbs, which seemed to have sperm clumps caught in them.

The researchers think that the spines might serve to remove a competitor’s sperm from the partner’s female reproductive organs. Since a sea slug’s female organs are able to store sperm from multiple partners at a time, this could be a way of clearing out the competition, the authors note.

It would take genetic analysis on the removed sperm to confirm this, the scientists say. In any case, the barbs would could act like a grappling hook, catching inside the vagina, making the penis difficult to remove after sex.

“This difficulty must be the essential reason for the particular penis [amputation],” the authors note.

Record number of dolphins dying off East Coast in ‘measles’ outbreak

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A dolphin swims off the coast of Florida.2005 Florida Keys News Bureau
The deadliest known outbreak of a measles-like virus in bottlenose dolphins has killed a record number of the marine mammals along the U.S. Atlantic coast in recent months, officials said Friday.

A total of 753 bottlenose dolphins have washed up from New York to Florida from July 1 until Nov. 3, according to the National Oceanic and Atmospheric Administration (NOAA).

The figure represents a 10-fold increase in the number of dolphins that would typically turn up dead along East Coast beaches, said Teri Rowles, program coordinator of the NOAA Fisheries Marine Mammal Health and Stranding Response Program.

“Historic averages for this same time frame, same geographic area, is only 74, so you get an idea of the scope,” she told reporters.

The cause of death is morbillivirus, a form of marine mammal measles that is similar to canine distemper and can cause pneumonia, suppressed immune function and brain infections that are usually fatal. The virus spreads among dolphins in close contact to one another.

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