Bilateral gynandromorph: the fate of a half-male, half-female bird

By on December 24th 2014 in Animals science

bilateral-gynandromorph-1

Yes I know what you are thinking, this photo must be photoshopped. However it is not! It is a gynandromorph, an organism that contains both male and female characteristics.

Even more interesting, this particular bird, a Northern Cardinal (Cardinalis cardinalis) is a bilateral gynandromorph, with its left side appearing as a male cardinal, and the right side as a female. The demarcation is so clear that only when both halves of the bird were observed simultaneously was it evident that the bird was a bilateral gynandromorph.

Bilateral gynandromorphy arises very early in development, typically when the organism is still only a few cells large. This happens when one of the dividing cells does not split its sex chromosomes as normal, leading to one of the two cells having sex chromosomes that cause male development, and the other cell having chromosomes that cause female development.

bilateral-gynandromorph-2

Researchers have long known such split-sex gynandromorphs exist in a range of animals such as insects, crustaceans, and birds but rarely have scientists been able to study them. For this particular bird two scientists were able to follow it for more than 40 days and to document how it interacted with other birds and responded to various bird calls.

What they found is that the cardinal did not have a mate nor was it ever heard singning, the researchers report this month in The Wilson Journal of Ornithology. The observers luckily also observed that the bird’s unusual looks did not raise any fierce aggression in its fellow cardinals.

References

Peer, B. D., & Motz, R. W. (2014). Observations of a Bilateral Gynandromorph Northern Cardinal (Cardinalis cardinalis) The Wilson Journal of Ornithology, 126 (4), 778-781 DOI: 10.1676/14-025.1

New species of woolly sea cucumber named after scientist’s dog

By on October 9th 2014 in Animals science
The "woolly" looking Phyrella mookiei, a newly discovered sea cucumber named after pet dog "Mookie"

The “woolly” looking Phyrella mookiei, a newly discovered sea cucumber named after pet dog “Mookie”

Scientists have discovered a new species of sea cucumber with a woolly look. What is great about this discovery is the researchers creativity in labelling it. Phyrella mookiei got its name from its resemblence to Mookie, the pet dog of one of the research assistants on the project! Quoting the paper:

Named after Mookie, the dog of our collection assistant Ms. Mandy Bemis, because the “woolly” appearance and color of this species is similar to the soft coat of wheaten terriers, the breed to which Mookie belongs.

This beautiful and relatively rare species is only known from the island of Guam. Already back in 2010 the team collected what they thought was a new sea cucumber species, but it took them four painstaking years to finally describe it.

Top view of the beautiful Phyrella mookiei sea cucumber

Top view of the beautiful Phyrella mookiei sea cucumber

With that they not only described this fascinating new species, they fully revised the whole genus of Phyrella for which they had to read through loads of old taxonomic descriptions and examine specimens from all around the world. This turned into a large and very detailed paper of over 40 pages long. Here is a section of the paper to give you an idea:

Description. External morphology. Body wall soft, fairly thin, densely covered with tube feet. Beige (UF 4770, UF 11539) to off-white (UF 10336), with well-defined burgundy (UF 4770, UF 10336) to dark brown (UF 11539) spots either restricted to venter (UF 4770) or across entire body (UF 10336, UF 11539); area around introvert and cloaca with diffuse burgundy coloration in UF 10336 (Fig. 11A). Coloration in preservative similar to live after 3 years. Oral disc marbled with burgundy and white (Fig. 10, Fig. 11B). Tentacles dendritic with long- stalk, with small dark spots at their extremities (Fig. 10, Fig. 11B). Body relatively straight when fully relaxed, contracting to U-shaped. Holotype 60 mm long along dorsum, 64 mm along venter and 18 mm wide; UF 4770, more contracted, 40 mm long along dorsum, 57 mm long along venter, and 23 mm wide; UF 11539 very contracted, 37 mm long along dorsum, 45 mm long along venter, and 16 mm wide. Introvert retracted in all pecimens, 4 mm (UF 10336), 6 mm (UF 4770), and 12 mm (UF 11539) long. Tube feet abundant, evenly dispersed across radial and inter-radial areas, slightly denser ventrally, generally same color as body wall near base, lightening distally. Eighteen tentacles (10 on outer circle, 8 on inner circle) in UF 4770, ~17 tentacles in holotype based on live pictures (introvert retracted and not dissected). Cloacal membrane white; surrounded by 5 calcified anal teeth.

Taxonomy helps to understand the evolutionary history of species by giving a rough idea of the position of species on the tree of life. Where scientists first mainly used morphological characteristics to characterise species, now DNA techniques play an important role to infer which species are related to one another. This study is a prime example of that as before this study all Phyrella were thought to have 20 tentacles, but a painstaking counting of the tentacles of many specimens revealed that this number is highly variable, even within a species.

close-up of sea cucumber

The head of Phyrella-mookiei showing the oral region.

I love it when researchers add a bit of humour to the often serious science and a sea cucumber named after a pet dog is a great example of that!

You can download the full article here and read more about the discovery by Francois’ and his team here.

References

Michonneau F, & Paulay G (2014). Revision of the genus Phyrella (Holothuroidea: Dendrochirotida) with the description of a new species from Guam. Zootaxa, 3760, 101-40 PMID: 24870076

Three new species discovered in tropical northern Australia

By on November 2nd 2013 in Animals science

Earlier this year, a team of scientists and filmmakers funded by National Geographic explored the depth’s of north Australia’s Cape Melville misty rain forest in search for the amazing animals that inhabit it. The team decided to discover this isolated rainforest in the tropical north of Australia as it has been cut off for millennia and therefore could well harbour unique species that live nowhere else.

Cape Melville

Pockets of rain forest dot the boulder fields of the mountain range on Cape Melville. Photo by Tim Laman, National Geographic.

The team including photographer Tim Laman and tropical biologist Conrad Hoskin discovered three species new to science: an amazing-looking leaf-tailed gecko with spindly legs and unusually big eyes [1], a new frog species [3] and a skink [2]!

Cape Melville Leaf-tailed gecko

The new species of leaf-tailed gecko sitting on a tree in Cape Melville’s rain forest. Photo by Tim Laman, National Geographic.

The Cape Melville leaf-tailed gecko (Saltuarius eximius) is very different from its tropical relatives because of its long legs—likely used to scramble around rocks—and large eyes, which helps it see in the gloomy habitat. They have an amazing leaf-like tail that enables them to camouflage very well amongst the foliage.

Cape Melville Gecko

The incredibly well camouflaged Cape Melville leaf-tailed gecko. Photo by Tim Laman, National Geographic.

The geckos the team found had likely never seen people as they were very docile. Conrad Hoskin about his discovery:

I ran up through the rocks and this beautiful, strange-looking gecko was sitting on the tree looking at me. I was utterly blown away by the gecko and remember holding it in disbelief

See-through gecko

An x-ray of the newfound gecko shows an animal’s tail after regeneration—many lizards will shed their tails in an effort to escape predators.

Within two two days, the team discovered another two new species. A golden-brown species of skink living amongst the mossy boulders and frog species that lives on top of the boulder fields, nicely named the blotched boulder frog, Cophixalus petrophilus. What is unusual about this frog is that, in the absence of water, the tadpole actually develops within the egg, resulting in fully formed frogs to hatch out of the eggs.

Cape Melville skink

Dr Hoskin holds the newfound Cape Melville shade skink, Saproscincus salts. Photo by Tim Laman, National Geographic.

The blotched boulder frog

The blotched boulder frog, Cophixalus petrophilus. Photo by Tim Laman, National Geographic.

It is exciting that in a place like Australia which many people think is fairly well explored, there are still places like this where there are new species to discover! Read more about the discovery here, or find the papers using the links below.

CONRAD J. HOSKIN1 & PATRICK COUPER (2013). A spectacular new leaf-tailed gecko (Carphodactylidae: Saltuarius) from the Melville Range, north-east Australia Zootaxa DOI: 10.11646/zootaxa.3717.4.6

CJ HOSKIN (2013). A new frog species (Microhylidae: Cophixalus) from boulder-pile habitat of Cape Melville, north-east Australia Zootaxa DOI: 10.11646/zootaxa.3722.1.5

CONRAD J HOSKIN (2013). A new skink (Scincidae: Saproscincus) from rocky rainforest habitat on Cape Melville, north-east Australia Zootaxa DOI: 10.11646/zootaxa.3722.3.7

New snail species discovered with semi-transparent shell

By on November 1st 2013 in science
See through snail

The cave-dwelling snail Zospeum tholussum. Photo by J. Bedek.

Scientists have discovered a fascinating new species of snail, deep down in one of the deepest cave systems in the world, Lukina Jama–Trojama in Croatia. The new species, named Zospeum tholussum, is not only extremely tiny (1.4 to 1.8 mm tall), it’s beautifully shaped dome-like shell is translucent, enabling you to see its guts! As many cave-living species, these snails are blind and have a limited ability to move.

Transparent snail

Close-up of the shell of Zospeum tholussum. Photo by J. Bedek.

Although scientists discovered a number of shells of this new rare species, just one specimen was found alive during an expedition of the Croatian cave system. The living specimen was found at the remarkable depth of 980 m where air temperature was around 3 degrees Celsius and air humidity 100%.

The fact that only one living specimen was found makes proper taxonomy a bit questionable as it is very difficult to distinguish variability in shells of the same and closely related species. Nevertheless, by using a molecular technique known as DNA barcoding, the author of this study published in Subterranean BiologyDr Weigand, could confirm this tiny snail is indeed a new species.

Lukina Jama Trojama cave

The chamber where the living snail specimen was found, almost 1k below the earth’s surface. Photo by Darko Baksic.

The Lukina Jama–Trojama where this fascinating new species was found is the deepest cave system in Croatia. It is unusual for its vertical shape, long pits and great depth of almost 1.4km and from an ecological point of view is very interesting for having different microclimatic layers, which provide unusual living conditions.

Alexander M. Weigand (2013). New Zospeum species (Gastropoda, Ellobioidea, Carychiidae) from 980 m depth in the Lukina Jama – Trojama cave system (Velebit Mts., Croatia) Subterranean Biology DOI: 10.3897/subtbiol.11.5966

Watching cute animal pictures boosts performance

By on October 4th 2012 in science

A lot of you fellow readers will be happy to hear the following: Japanese scientists have demonstrated that watching cute animal pictures may actually boost your work performance by inspiring more attention and careful behaviour!

Cute picture of puppy and baby rabbits

“Mmm you to rabbit pillows are so nice and fluffy!” Photo by Jane Burton

It is not surprising that this study comes from researchers in Japan since in particular Japan’s culture accepts and appreciates cuteness and childishness at the social level, think of for example Helly Kitty and Pokemon! They love cute animal pictures there!

In the first experiment subjects performed a children’s game that tests players’ hand-eye coordination and fine motor skills (similar to the ‘operation game). Using tweezers, the participants were asked to remove 14 small pieces from holes on the patient’s body depicted on the game board without touching the edges of the holes. Those who looked at photos of cute baby animals before performing the test tests ended up with a performance score 44 per cent higher on average than the group who had looked at adult animals.

Performance improves considerably more after seeing pictures of cute animals than adult animals or pleasant food.

Further experiments showed that visual performance was also considerably improved by cute images, while looking at images of nice food affected subject’s performance very little. Furthermore, the researchers found the cute-picture-viewing participants were better at honing in on local features than identifying big-picture elements of visual stimuli.

These results thus show that perceiving cuteness not only improves fine motor skills but also increases perceptual carefulness. “For future applications, cute objects may be used as an emotion elicitor to induce careful behavioral tendencies in specific situations, such as driving and office work” the authors conclude.

What better way to start the day than by watching pictures of cute animals!

Cute grey pets

Okay, one more! Photo by Jane Burton

Cute animal picture pets

“I like to lick you rabbit..” Photo by Jane Burton

Cute animal picture - fluffy pets

“Oow this rabbit is so nice and fluffly” Photo byJane Burton

Cute animal picture - pets playing

“C’mon rabbit, let’s play!” Photo by Jane Burton

Cute animal picture - dog playing

“Get away from me you cute rabbit” Photo byJane Burton

Cute animal picture - dog and rabbit

“Rabbit, I feel a bit uncomfortable…” Photo by Jane Burton

Cute animal picture - tiny dog and rabbit

Tiny dog + same coloured rabbit = cute! Photo by Jane Burton

Cute animal picture - puppy and rabbit

Cute picture of a dog and rabbit. Photo by Jane Burton

Cute animal picture - black and white pets

Same-coloured dog and rabbit. Photo by Jane Burton

Cute animal picture - baby rabbits and kitten

More cuteness, black and white kitten and rabbits! Photo by Jane Burton

Cute animal picture - sleeping dog

Cute picture of a dog and rabbit. Photo by Jane Burton

Cute kitten likes rabbit

“I like you mr big rabbit!” Photo by Jane Burton

Now back to work, but fully concentrated!

Hiroshi Nittono, Michiko Fukushima, Akihiro Yano, Hiroki Moriya (2012). The Power of Kawaii: Viewing Cute Images Promotes a Careful Behavior and Narrows Attentional Focus PLOS ONE, 7 (9) DOI: 10.1371/journal.pone.0046362

Bar-headed geese cross Himalayas in one night

By on June 4th 2011 in science
Bar-headed geese migration

Beautiful photo of two bar-headed geese migrating. Photo by John Downer.

Bar-headed geese are known for their exhausting migration route over the Himalayas, reaching extreme heights up to 10,175m and traveling distances of 1500km in a single day. Although it was already known these high-flyers are physiologically and biochemically adapted to flying at these altitudes where oxygen levels and temperatures are both extremely low, it remained unclear how they performed this incredible energy-costly feat.

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Humpback whale culturally transmit their songs

By on April 28th 2011 in science

Humpback whales are famous for their extraordinary songs, which are amongst the most complex in the animal kingdom. Now researchers from the University of Queensland have revealed that multiple song types spread rapidly and repeatedly like cultural waves, eastward across the Pacific Ocean.

Humpback whales

The plaintive song of the humpback whale can travel for great distances underwater. Photo by Dr. Louis M. Herman/NOAA

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World record non-stop flight for the Bar-Tailed Godwit

By on July 16th 2010 in science
Bar-tailed godwit

Bar-tailed Godwit’s make world record flights across the world.

Alaskan Bar-Tailed Godwits just look like an ordinary shorebird. Recent research however has discovered that these waders are the new world record holders for non-stop flight. Every autumn, these extreme migrators fly an astonishing 11.000km from Alaska to New Zealand without any stopovers to rest or refuel. This roughly doubles the previous maximum known non-stop distance for migratory birds.

The non-stop flight of the godwit’s is even more impressive if one takes into account that the current world-record for a manmade flying device is 82 hours, less than half that of the godwits.

Gill and colleagues (2009) used satellite telemetry to track 23 birds on their trip across the pacific. By this relatively new technique in which the position of each individual bird is sent to a satellite every six hours, the authors found out the birds need on average 8 days to make the crossing.

Bar-tailed godwit record flight

Southward flight tracks of nine bar-tailed godwits fitted with satellite transmitters.

These extraordinary non-stop flights establish new extremes for the flight performance of birds. There are birds however with even longer migrations than that of the Alaska Bar-Tailed Godwit. For example the pectoral sandpiper which flies 16000km with at least one break in between, and the impressive 24000km northbound spring migration of the arctic tern. The difference is that these birds have the opportunity to feed and rest at sea as they go and thus do not need to fly non-stop.

So how are these birds able to fly non-stop for 8 days across the pacific? Professor Hedenström assessed the unbelievable aerial feat in a interesting paper published in PLoS Biology this spring. He calculated that the birds only use some 0.41% of their body mass per hour which is the lowest value thus far for any powered animal flight. This is important because the godwits have to take just as much on board before departure to sustain them for the 8 day flight. Furthermore, it is important the birds have exactly the right body weight to size and have an aerodynamic body shape. Very crucial for the godwit’s journey is their high flight speed which makes them relatively immune for crosswinds.

Bar-tailed godwit

A bar-tailed godwit standing in the grass.

Gill and colleagues propose that the reason why these birds travel along this transoceanic route because it may function as a safe corridor, providing a wind-assisted passage relatively free of hungry predators and harmful pathogens.

The amazing feat of the bar-tailed godwit leaves us with many new questions. How can the birds orientate while flying over the vast stretches of ocean? How do they manage to exert such high levels of exercise for such an amount of time? And how do they deal with dehydration and sleep deprivation? This is a good example again of how new scientific discoveries will often lead to even more unsolved questions. That’s the beauty of science.

Gill, R., Tibbitts, T., Douglas, D., Handel, C., Mulcahy, D., Gottschalck, J., Warnock, N., McCaffery, B., Battley, P., & Piersma, T. (2009). Extreme endurance flights by landbirds crossing the Pacific Ocean: ecological corridor rather than barrier? Proceedings of the Royal Society B: Biological Sciences, 276 (1656), 447-457 DOI: 10.1098/rspb.2008.1142

Hedenström, A. (2010). Extreme Endurance Migration: What Is the Limit to Non-Stop Flight? PLoS Biology, 8 (5) DOI: 10.1371/journal.pbio.1000362

Sloths bizarre feeding habit: eating toilet contents!

By on June 10th 2010 in science

Sloths are mostly known as rather slow-moving adorable creatures that spend their days eating leaves and sleeping. However, a recent paper in the journal Mammalian Biology shows they might actually have a side to them that makes them a little less adorable. Heymann and colleagues (2010) reported that two-toed sloths were found to have developed the charming habit of climbing into an outdoor toilet and eating its contents! This unusual feeding habit was observed at a research station in the Amazon rainforest of North-eastern Peru.

Sloth in toilet

A sloth coming out of a toilet, just having had a dirty meal..

On the first occasion in 2001, a researcher wanting to use the toilet discovered a sloth was inside the toilet, hanging upside down underneath the wooden bars. “The sloth was scooping with one hand from the semi-liquid manure composed of faces, urine, and toilet paper and then eating from the hand”, as the authors nicely describe.

A total of more than 25 of these sloth excursions were observed during the following years. On one occasion even a mother holding her baby was seen visiting the toilet! (see picture below).

Baby sloth in toilet

A female sloth and her baby entering a toilet. Photo by M. Stojan-Dolar.

Although this peculiar behaviour might at first glance look like a bizarre anecdote, the authors speculate that in this way sloths might be vulnerable to human diseases since sloths often live close to people.

So why would these sloths prefer human waste material to fresh leaves?

Normally sloths hardly ever come down from the trees in which they live. They only descend to the forest floor to change trees or once to twice a week to defecate, making the behaviour even more surprising.

The authors put forward three possibilities for the sloths radical behaviour: they might feed on faeces as a direct source of nutrients, they may gulp the semi-liquid contents of the toilet to acquire salt and minerals, or they may be eating insect larvae that are present.

Sloth eating toilet contents

A dirty sloth that just had a nice evening meal in the camp toilet. Photo by M. Stojan-Dolar.

I think the sloths might indeed feed on human faeces because if often contains a lot of wasted nutrients. It may not even be that rare, since most dogs can be found doing ‘something’ similar (although not actually entering a toilet ;) ). However, I guess the people at the research station were probably not eating a very nutrient-rich diet, since they were living at such a remote location.

Although sloths may be a little less adorable now, they have become even more fascinating because of this bizarre behaviour! What do you think about sloths and their unusual feeding habit?

Heymann, E., Flores Amasifuén, C., Shahuano Tello, N., Tirado Herrera, E., & Stojan-Dolar, M. (2010). Disgusting appetite: Two-toed sloths feeding in human latrines Mammalian Biology – Zeitschrift fur Saugetierkunde DOI: 10.1016/j.mambio.2010.03.003