Showing posts with label blood-suckers. Show all posts
Showing posts with label blood-suckers. Show all posts

Sunday, 25 February 2018

DNA secrets of how vampire bats became bloodthirsty


By Helen Briggs BBC News
19 February 2018

DNA analysis is giving clues to how the vampire bat can survive on blood alone.

The bat can drink up to half its weight in blood a day unlike other relatives, which dine on fruit, nectar or insects.

Blood is low in nutrients and can harbour deadly viruses.

Vampire bats have key differences in genes involved in immunity and food metabolism compared with other bats.

The researchers say the bat's gut microbes are also distinct.

They found evidence of more than 280 types of bacteria in the bat's droppings that would have made most other mammals unwell.

"The data suggests that there is a close evolutionary relationship between the gut microbiome and the genome of the vampire bat for adaptation to sanguivory (feeding exclusively on blood)," said study author, Dr Marie Zepeda Mendoza of the University of Copenhagen in Denmark.

The common vampire bat harbours many genes that have been selected to cope with blood feeding, she added.


Saturday, 3 March 2012

Monster fleas sucked the blood of Jurassic dinosaurs

It seems that dinosaurs weren’t the only scary monsters of the Jurassic period as newly-discovered fossils reveal giant blood-sucking fleas afflicted the prehistoric world.

Scientists say that the 2cm-long parasites, which roamed the planet between the Middle Jurassic and Lower Cretaceous, were up to four times larger than their descendants - the fleas we see today.

Nine perfectly preserved fossils were unearthed from 165-million-year-old Jurassic deposits in Daohugou, northeast China, and the 125-million-year-old Cretaceous strata at Huangbanjigou, China.


The female fleas were a huge 20mm in length, while the slightly smaller males still measured in at 15mm. 
The biggest fleas to be found today have a maximum length of 5mm.
While they didn’t have wings and weren’t able to jump, their remains show how they were specially adapted to the feed off their prey, said the study published in the ‘Nature’ journal.

Saturday, 4 February 2012

A Battle of the Vampires, 20 Million Years Ago?

ScienceDaily (Feb. 3, 2012) — They are tiny, ugly, disease-carrying little blood-suckers that most people have never seen or heard of, but a new discovery in a one-of-a-kind fossil shows that "bat flies" have been doing their noxious business with bats for at least 20 million years.

For bats, that's a long time to deal with a parasite doing its best vampire impression. Maybe it is nature's revenge on the vampire bat, an aggressive blood consumer in its own right that will feed on anything from sheep to dogs and humans.
The find was made by researchers from Oregon State University in amber from the Dominican Republic that was formed 20-30 million years ago. The bat fly was entombed and perfectly preserved for all that time in what was then oozing tree sap and later became a semi-precious stone.
This is the only fossil ever found of a bat fly, and scientists say it's an extraordinary discovery. It was also carrying malaria, further evidence of the long time that malaria has been prevalent in the New World. The genus of bat fly discovered in this research is now extinct.
The findings have been published in two professional journals, Systematic Parasitology and Parasites and Vectors.
"Bat flies are a remarkable case of specific evolution, animals that have co-evolved with bats and are found nowhere else," said George Poinar, Jr., an OSU professor of zoology and one of the world's leading experts on the study of ancient ecosystems through plants and animals preserved in amber.
"Bats are mammals that go back about 50 million years, the only true flying mammal, and the earliest species had claws and climbed trees," Poinar said. "We now know that bat flies have been parasitizing them for at least half that time, and they are found exclusively in their fur. They are somewhat flat-sided like a flea, allowing them to move more easily through bat fur."
Not every bat is infested with bat flies, and some of the contemporary flies are specific to certain species of bats. But they are still pretty common and found around the world.
Bat flies only leave their bat in order to mate, Poinar said, and that's probably what this specimen was doing when it got stuck in some sticky, oozing sap.

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