Endless Forms

Cutting edge news about discoveries in ecology, evolution and conservation.


Leave a comment

New Species of 2016: The Fab Five

As the year draws to a close, lists and “best of 2016” articles are being written for everything from world leaders to television shows to hamburgers. In the midst of all of the other headlines in 2016, new species were being discovered all over world. Here is a curated list of my five favorite creatures that were first reported in 2016.

1. Flightless scaly-tailed squirrel (Zenkerella insignis)

220px-aethurus_glirinus

This small mammal makes the list for essentially being rediscovered, after only being known to science via fossils and a handful of aging specimens. Previously, no one knew if living flightless scaly-tailed squirrels still walked the earth at all.

Zenkerella insignis began roaming the landscapes and islands of what is now western Africa around 50 million years ago — just 15 million years after dinosaurs went extinct. This scaly-tailed squirrel provides a peek into the past, as  the species has changed very little since then. It is one of only six extant (living) mammal species to boast such a long tenure on our planet.

equatorial-guineaZenkerella insignis‘s rediscovery also serves as a lesson about the value of maintaining museum collections and supporting research expeditions that focus on exploration and discovery. Dr. David Hernandez, a lecturer at the University of West England, came across a Z. insignis specimen that had been languishing in a museum collection for some time, and texted a picture of it to his colleague Dr. Erik Seifert, at the University of Southern California. That text message eventually inspired a new field expedition to search for a surviving population on Bioko Island, off the coast of Equatorial Guinea. Thus, while this is anything but a “new” species, the expedition’s discovery of an island population of “living fossils” was a new and noteworthy revelation.

imrs-php

Zenkerella insignis specimen (Credit: Steven Heritage)

 

2. New species of basslet named in honor of President Obama (Tosanoides obama)

hawaiisnewes

Tosanoides obama (Credit: Richard L. Pyle, Bishop Museum)

While this small tropical fish doesn’t have an official common name yet, its Latin name has made it an immediate celebrity: Tosanoides obama was named in honor of U.S. President Barack Obama, in honor of his contributions to marine conservation. This basslet was discovered in Papahānaumokuākea Marine National Monument (PMNM), surrounding the far northwest Hawaiian islands. When Obama expanded PMNM in August 2016, he made it the largest protected wildlife reserve in the world–marine or terrestrial– covering 582,578 square miles (1,508,870 square km). That is approximately twice the size of Texas.

In addition to T. obama, PMNM is home to around 7,000 species, including endangered sea turtles and marine mammals. With the expansion of the park, we can look forward to a wealth of new research from that part of the Pacific.

2-hawaiisnewes

Credit: Brian Skerry

 

3. Ruby seadragon (Phyllopteryx dewysea)

image_2515-phyllopteryx-dewysea

Phyllopteryx dewysea (Credit: Western Australia Museum)

Here there be dragons. The list of known sea dragon species increased by 50% this year, with the discovery of only the third species known to science. The ruby sea dragon (Phyllopteryx dewysea), found off the coast of Western Australia, is the first new sea dragon species to be described in over 150 years.

What is a sea dragon, anyway? It is a highly derived fish, and is closely related to the sea horses. They are not strong swimmers, and tend to “go with the flow,” gliding along in the ocean waves.  Phyllopteryx dewysea is a deeper red color than the other two known species of sea dragon, leading researchers to believe that it may spend its time deeper in the ocean waters than its relatives. Red wavelengths of light are absorbed underwater, making red a better and better camouflage the deeper one dives. This preference for deeper waters could also explain why the species hadn’t been discovered until this year.

4. Peacock spider (Maratus spp.)

Peacock spiders are gorgeous and entertaining little arachnids. This year not one but seven new peacock spider species were described, all in the genus Maratus. These jumping spiders are known for the bright, iridescent patterns that adorn the males. As with peacocks, males use these colorful features as part of elaborate courtship displays, and females are drab in comparison.

My personal favorite from the Peacock Spider Class of 2016 is M. bubo: “Bubo” is genus name for horned owls and eagle-owls, in honor of the colorful pattern on this spider that looks like a tiny owl portrait.

99933028_a_specimen_of_the_newly-discovered_australian_peacock_spider_maratus_bubo_shows_off_his_col-large_transeo_i_u9apj8ruoebjoaht0k9u7hhrjvuo-zlengruma

Maratus bubo (Credit: Jürgen Otto)

See video of peacock spiders dancing

Check out the peacock spider Facebook page

5. Ghost octopus (Latin name TBD)

ghost-octopus

In February of 2016, scientists at the National Oceanic and Atmospheric Administration (NOAA) unveiled a surprise character from deep-sea rover footage: a round, pale little octopus that was previously unknown to science. Living at a depth of over 4,000 meters (13,123 feet, or about 2.5 miles), this creature is thought to be not only a new species, but an entirely new genus.

And it’s cute: this cephalopod charmed the world, becoming an internet sensation overnight, frequently being compared to Casper the friendly ghost.

The “ghostopus” is so unique that more analysis must be done before it can be officially described and named. Meanwhile, more exploration of the sea floor around the Hawaiian islands may turn up more individuals, and even more species not yet known to science.


Leave a comment

The Lemur Underground

hibernation_header

From bears slumbering in their dens to frogs sinking into muddy tombs of suspended animation, a wide spectrum of animals use hibernation to survive inhospitable seasons.

We tend to associate hibernating creatures with cold, wintry environments – just a mention of hibernation conjures images of snow-blanketed forests and ice-covered ponds. A group of small tropical primates is breaking the trend, however—recent research has revealed that dwarf lemurs in Madagascar hibernate for up to eight months of the year.

madagascar_smap

Madagascar (in red box)

furryeareddwarflemurwimruitenbeek

Cheirogaleus crossleyi

While scientists already knew that that the western fat-tailed dwarf lemur (Cheirogaleus medius) spends seven months of the year hibernating in tree holes (Dausmann et al. 2004), until recently there was no evidence that any other primate species on earth undertakes significant hibernation periods. A recent paper in Nature’s open access journal, Scientific Reports, presents new evidence of hibernation in two other primate species, the Sibree’s dwarf lemur (C. sibreei) and the Crossley’s dwarf lemur (C. crossleyi), both of which occur in east-central Madagascar’s high altitude forests (Blanco et al. 2013). While it may not seem as though primates would need to hibernate on a tropical island, Madagascar’s mountainous regions can indeed experience temperatures that dip below freezing—a significant thermoregulatory challenge for a squirrel-sized primate. Thus, a research group from Duke University Lemur Center decided to see if the overwintering strategies of eastern dwarf lemurs resembled that of the western species.

The researchers managed to trap dwarf lemurs prior to hibernation season, and outfitted each animal with a collar that featured both a radio transmitter and a temperature sensor. The collars allowed the animals to be located after they had retreated to their hibernacula, in addition to tracking fluctuations in body temperature while the lemurs were hibernating.

madagascar_forests_110356_356027

Eastern Madagascar

The researchers found that not only do these tropical lemurs hibernate for 3-6 months out of the year, the arboreal creatures actually spend their hibernation underground, despite their lack of adaptations for a fossorial (digging and burrowing) lifestyle. The lemurs nestled 10-40 cm (4-16 inches) beneath a the forest’s floor of secondary roots and humus, no small feat for an animal that appears to be optimized for life in the treetops. Each lemur denned up alone, and they used just one or two hibernacula sites per season.

This underground hibernation habit is intriguing; the other lemur species known to hibernate, C. medius, uses tree hollows exclusively. The researchers suggest that this difference in hibernation sites could be partially due to constraints imposed by soil type: soil in C. medius’ habitat is hard and dry, unlike the soft soils of the eastern forests. Another interesting point about hibernacula choice is that the eastern species use tree hollows, rather than burrows, for their normal resting periods during the non-hibernation season, meaning that hibernation is an event with a very specific site selection pattern, rather than just an extended rest in their usual shelters.

Temperature data from the collars showed that C. sibreei and C. crossleyi tend to keep their body temperatures more stable than C. medius, which may highlight another advantage of subterranean hibernation. Soil provides more resistance to ambient temperature fluctuations than hollow trees, meaning that the eastern species are better insulated during hibernation than their western relative.

A final noteworthy aspect of this study is that C. sibreei and C. crossleyi are basal species (less derived than many other species) within their branch of the lemur phylogeny. This raises the question of whether their hibernation patterns may be an ancestral condition for dwarf lemurs. In the mean time, you never know what could be underfoot in the forest . . .

Sources:

Blanco, M. B., Dausmann, K. H., Ranaivoarisoa, J. F., Yoder, A. D. 2013. Underground hibernation in a primate. Science Reports. 3:1768.

Dausmann, K. H., Glos, J., Ganzhorn, J. U., Heldmaier, G. 2013. Hibernation in a tropical primate. Nature. 429:825-826.

 

 

 


Leave a comment

From Carrion to Carriers: Crows Transmit Infectious Prions

Most of us recall learning the basic rules of protein structure and folding in high school science classes (if not, see neat interactive animations here). Basically, form equals function, and a protein must be correctly folded in order to perform its duties. The critical nature of this process cannot be overstated, and the results of misfolded proteins in the brain—also known as prions—can be gruesome.

pdb_1b10_ebi

Rabies, “mad cow disease,” foot-and-mouth disease, kuru, chronic wasting disease—all of these ghastly illnesses are caused by prions, which are more technically known as transmissible spongiform encephalopathies (TSEs). Foaming at the mouth, loss of muscle control, hallucinations, hydrophobia . . . the symptoms of prion disorders can lead to truly tragic and painful deaths, all ultimately due to a few misshapen proteins.

Despite the Hollywood-worthy symptoms of prion disorders, the most disturbing part of a TSE is the ‘T’ part: “transmissible.” The specter of such a devastating brain disease being passed from one individual to another seems like something out of a cheap horror novel—and yet it happens every day.

We typically think about TSE infections as resulting from direct contact with an infected animal. However, what if you could become infected simply from exposure to feces left by an exposed yet unsymptomatic vector? A recent PLoS ONE paper describes a study on passive transmission of infectious prions by crows, highlighting a form of prion dissemination that is little-known, yet potentially very important from a disease ecology perspective. What happens when prions can hitch rides on non-symptomatic, aerial hosts?

Crows are notorious scavengers, and feed upon carcasses that may have died from any number of traumas or diseases. It is already known that TSE diseases can be spread by the consumption of flesh: kuru, a lethal form of encephalopathy found amongst the Fore people of Papua New Guinea, is transmitted through ritual cannibalism during funeral rites. Given that prion disorders such as chronic wasting disease and rabies are not uncommon amongst wildlife, there is a realistic possibility that scavengers will be exposed to TSE-infected flesh. The risks to scavengers are obvious, but the hazards extend beyond these animals. Will the prion strains remain infective after the infected food has been digested and excreted? This is a critical question that must be answered if we are to understand the role that scavengers play in transporting pathogens from place to place after feeding on carrion.

AMERICAN_CROW_(7143675301).jpg

In the recent experiment reported by VerCauteren and colleagues, 20 American crows (Corvus brachyrhynchus) were fed mouse brain material infected with scrapie prions, to simulate feeding upon prion-infected carcasses. Next, the researchers obtained feces samples from the birds, and injected them into lab mice (the CF+ treatment group) to see if the disease remained infectious after passing through the birds’ digestive systems. Another set of mice (the MB+ treatment group) was injected directly with infected mouse brain material—the same substance that had been fed to the crows.

The results were striking. There were a handful of fatalities due to toxicity from uric acid in the bird feces, but all of the mice that survived for at least three days after the inoculations  exhibited neurological dysfunctions characteristic of prion disorders. They also all tested positive for prion infection during their postmortem examinations.

Mice that were injected directly with mouse brain material (the MB+ group) developed neurological symptoms 15 days earlier than those infected through crow fecal material (CF+ group), suggesting that indirect infection may provide a smaller dose, although still enough to be ultimately lethal. Between 83-100% of the crows were estimated to produce feces capable of infecting mammals with the prion disorder.

It is important to keep these results in perspective. This study was designed to provide conservative estimates of post-digestion prion infectivity. The type of scrapie that was used in this study, the RML Chandler strain, is more sensitive to enzymatic activity than many others. This means that more robust strains of prion disorders may be even more infective after ingestion and excretion by birds – an ominous scenario indeed.

The implications of these results are important and fascinating. The takeaway message of this study was that prions can remain lethally infectious after they have been digested and excreted by an avian scavenger. Crows produced infective feces within four hours of feeding, and in that amount of time a crow can travel a nontrivial distance from its initial feeding site.

This kind of transmission by volant scavengers could turn a TSE outbreak from a local, individually transmitted event into a much broader outbreak. Further research on how long prions remain infective in the feces under different environmental conditions will provide additional insights into how avian scavengers may affect the transmission dynamics of these diseases.

USFWS_crow_(23557832520).jpg

 

Source:

Prion Remains Infectious after Passage through Digestive System of American Crows (Corvus brachyrhynchos). Vercauteren, K. C., Pilon, J. L., Nash, P. B., Phillips, G. E. , and Fischer, J. W. PLoS ONE. http://dx.doi.org/10.1371/journal.pone.0045774