A peculiar case of age and hunger-defying African ticks

It seems a cruel trick that of all of nature’s creatures, those that have found ways to be extremely resilient — and even survive for many years without food — are among the most obscure… or annoying and dangerous, like ticks.

Julian Shepherd, a US-based researcher, was gifted a particular species of large African tick in 1976 and observed them over a period of 27 years in his lab.

Almost by accident, Shepherd noticed that some of the female ticks survived without any food for eight of those years. Some even managed to reproduce and give birth more than four years after all the male ticks had died.

They belonged to the Argas brumpti species, a tick that’s generally found in eastern and southern parts of Africa.

The fact that this species lives so long breaks records in itself, writes Shepherd in a study published in the Journal of Medical Entomology. But the ability for any living creature to go so long without food is rare in science.

Only a few other animals can live for multiple years in complete “starvation mode.” The olm, an aquatic salamander, can do it. Crocodiles can do it, too. Tardigrades, a bizarre-looking micro-animal, can live for as much as 30 years without food.

Tardigrades can live up to 30 years without food

But Shepherd hadn’t intended to study this with his ticks.

“To tell the truth, I had no specific plans for them. I was just thinking of widening my experience with ticks,” Shepherd told DW. “I had no idea that they would [live so long].”

Feeding the ticks on himself

Shepherd’s discovery that A. brumpti can survive so long without food was basically a fluke.

He had stopped feeding them because they needed organisms larger than mice as a source for blood and that had created logistical and ethical problems, he said.

“I fed them on rabbits but that wasn’t as humane as I had wanted. I fed some on myself — but only once! And then I found I could feed them on blood drawn from rats that were being euthanized at an experimental animal facility.”

Soft and hard ticks

The A. brumpti is known as a “soft tick.”

Soft ticks are distinct from “hard ticks,” which are common in the US and Europe. Soft ticks are, for example, less likely to feed on humans, said Shepherd.

But they do transmit serious diseases, such as Tick-borne Relapsing Fever (TBRF), which is found in Africa, as well as the Mediterranean and parts of western North America.

TBRF is a bacterial infection that can cause recurring bouts of fever, headache, muscle and joint aches, and nausea.

The research continues

Shepherd recently sent his nature-defying ticks to South Africa, where he hopes other researchers will continue to look after them.  

He said the new researchers believe the ticks he was gifted all those years ago may in fact be multiple species. He says they may use DNA technology to further analyze the ticks’ genetic relationships.

But did his own work with these ticks reveal any tips on longevity for humans? It appears the answer is “no.”

“What enthralls me,” said Shepherd, “is just how some obscure organisms have found extraordinary ways to survive.”

• Elderly elephants, lonely giants and the secret of aging

  A hundred years, thousands of kilometers

  Long body, pointed “snout” and very tasty eggs: sturgeons are mostly known as the source of caviar. They can reach 100 years old – their longevity is even more impressive considering the thousands of kilometers they travel. Sturgeons spawn, meaning they are born in freshwater, swim to the oceans to live out their lives, and return to their home waters to reproduce.

• Elderly elephants, lonely giants and the secret of aging

  Fit by flying

  Flying seems to be a good way to stay in shape: among the animals with the longest lifespans are many birds, like the gray parrot. It can get up to 70 years old. The oldest known cockatoo resided in the London Zoo, and lived well past his 80th birthday. And ravens can become 90 years or older.

• Elderly elephants, lonely giants and the secret of aging

  Here’s looking at you, whale

  Bowhead whales can reach up to 200 years old. But determining their exact age can be challenging – researchers have to conduct a biochemical analysis of the whale’s eye. Sometimes, all it takes is a lucky coincidence: A couple of years ago, a piece of a harpoon dating back to 1890 was found in the flesh of a bowhead whale. So that one was definitely more than a hundred years old!

• Elderly elephants, lonely giants and the secret of aging

  Very human giants

  Elephants live together in herds, and are among the few wild species with hardly any natural enemies. If they aren’t slain by poachers, they can reach up to 70 years old. Led by an mature female or cow elephant, they wander Africa’s savannas in search of water and fresh grass. Perhaps their most human-like trait: they stop and mourn when they pass the place where an elephant from their herd died.

• Elderly elephants, lonely giants and the secret of aging

  The celebrity Methusaleh

  He led a lonely life for more than 100 years: Tortoise “Lonesome George” of Pinta Island in the Galapagos was long considered to be the last of his kind – Chelonoidis nigra abingdonii. Though lonely, he was popular, and was even preserved and displayed after he died. Giant tortoises of other species lived even longer – Galapagos tortoise Harriet died in 2006 at the age of 175.

• Elderly elephants, lonely giants and the secret of aging

  Rings like a tree

  Although this specimen doesn’t look particularly spectacular, it is highly interesting for scientists: the oldest ocean quahog ever found, at 410 years. Every year, the clam forms another “growth ring” at the edge of its shell. Researchers can learn about the climate or sea conditions of past centuries from the shells of old ocean quahogs.

• Elderly elephants, lonely giants and the secret of aging

  Grow slow, live long

  This sponge grows very slowly, but sticks around for a long time. Scolymastra joubini lives at the bottom of the Antarctic sea, and is older than any other animal: an estimated 10,000 years. Researchers at the Alfred Wegener Institute used the sponge’s oxygen uptake rate to help calculate its age.

  Author: Alexandra Hostert / cb

Article source: https://www.dw.com/en/a-peculiar-case-of-age-and-hunger-defying-african-ticks/a-61049157?maca=en-rss-en-all-1573-rdf