Saturday, 19 April 2014

First female “penis” discovered in cave-dwelling insects

Neotrogla aurora female penis
Image showing the female penis of N. aurora
Credit: Current Biology, Yoshizawa et al.
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Psocoptera
Family: Prionoglarididae
Genus: Neotrogla
Species: N. aurora, N. curvet and 2 other

This Thursday, researchers announced that they have discovered several insect species that display the "world's first" known instance of gender-reversed genitalia. In simple words, they have found 4 insect species with female... "penises" and male "vaginae"!

All four species live in dry Brazilian caves and feed on bat guano. They belong to the genus Neotrogla, of the Psocoptera order which is commonly known as booklice or barklice. They are small -2.7 mm to 3.7 mm long- and look like flies, with nothing particularly strange about their appearance other than their bizarre reproductive system.

"Although sex-role reversal has been identified in several different animals, Neotrogla is the only example in which the intromittent organ is also reversed." said leading author, Kazunori Yoshizawa from the Hokkaido University in Japan.

Prolonged and reversed mating
The researchers found that these insects mate for an impressive 40 to 70 hours, during which, the female inserts an elaborate, penis-like organ -called gynosome- into the male's vagina-like opening.

According to co-author Rodrigo Ferreira, the females may forcibly hold on the males for such long periods of time to get as much of their sperm and seminal fluid as possible.

"One of the couples copulated for around 73 hours." said Ferreira.

The spikes along the female penis anchors it to the male's "vagina" so strongly that when the researchers tried to separate one of the couples, they tore apart the male’s body without affecting the genital coupling.

N. curvet mating
Female N. curvet (top) mates with a male
Credit: Yoshizawa Kazunori

The researchers speculate that the prolonged copulation and the genitalia reversal may be an evolutionary trait guided by the resource-poor cave environment in which these insects live. Males provide females with nutritious seminal fluids in addition to sperm, making it advantageous for the females to mate for prolonged periods.

The findings on Neotrogla offer new opportunities to test ideas about sexual selection, conflict between the sexes, and the evolution of novelty, claim the researchers, who now plan to look into studies of behavior, physiology, and more. First on their list is to establish a healthy population of the insects in the lab.

"It will be important to unveil why, among many sex-role-reversed animals, only Neotrogla evolved the elaborated female penis." said Yoshitaka Kamimura from Keio University in Japan. 

It has a penis, so it should be a male, no?
Contrary to what common sense may tell you, the presence or absence of certain genitalia isn't the determining factor to whether an individual is male or female. Gametes are.  

By definition,male gametes are small, motile, and optimised to transport their genetic information over a distance, while female gametes are large, non-motile and contain the nutrients necessary for the early development of the young organism.

It just happens that males usually have a penis and females a vagina. Usually..

- Yoshizawa, K., Ferreira, R., Kamimura, Y., & Lienhard, C. (2014). Female Penis, Male Vagina, and Their Correlated Evolution in a Cave Insect Current Biology DOI: 10.1016/j.cub.2014.03.022

Monday, 7 April 2014

Illacme plenipes - World's leggiest creature

Image showing a Illacme plenipes specimen
Illacme plenipes
Credit: Paul Marek et. al.
Kingdom: Animalia
Phylum: Arthropoda
Class: Diplopoda
Order: Siphonophorida
Family: Siphonorhinidae
Genus: Illacme
Species: Illacme plenipes
Conservation Status: Not officially assessed, possibly threatened by extinction
Common Name: None

Despite their name, we have yet to discover a millipede species that has one thousand legs. However, the rare Illacme plenipes comes very close to this number, with one recorded specimen having 750 legs.

The species has only been found in a patch of grassy oak woodlands, spanning about 1.7 square miles near Oakland and Berkeley, California.

I. plenipes History
This millipede was first discovered by Orator Fuller Cook (1867–1949), an American botanist, entomologist, and agronomist. On November 27, 1926, O. F. Cook collected several specimens in San Benito County, California. He found only one colony, in a small valley of a northern slope wooded with oaks, under a rather large stone.

Since then, the species was not seen again and was thought to have gone extinct. However, it was rediscovered about 80 years later, in November 2005, by Paul Marek, who was conducting research on millipede systematics and evolution in San Benito County.

This specimen had 662 legs

I. plenipes Description
Their body is slender and flexible, filiform, strongly and evenly convex. The largest recorded specimen was a female, with 192 segments, a length of 36 mm and a width of 0.7 mm. Other specimens were 26 to 29 mm. long, 0.5 to 0.6 mm. wide, and had 136 to 152 segments. Each segment features 4 four legs.

On average, they have over 600 legs, which is twice the average for millipede species. Females grow to just over an inch while males are slightly smaller and have fewer legs. The body is covered by little hairs that secrete a viscous silk-like substance.

Despite having more legs than any other known species on Earth, they are actually quite small, even by millipede standards. For comparison, the monstrous Archispirostreptus gigas which grows up to 38.5 centimetres (15.2 in) in length has "only" 256 legs.

image showing Archispirostreptus gigas
Archispirostreptus gigas

They have a whitish colour, move very slowly and roll themselves into spiral coils when disturbed. Essentially, they look like white pieces of thread.

They have no eyes, disproportionately long antennae and a rudimentary fused mouth adapted for sucking and piercing plant structures.

Scanning electron micrograph image of Illacme plenipes' head and antennae,
showing the little hairs that cover its body.
Credit: Paul Marek et. al.

I. plenipes Leg Use
Millipedes typically use their numerous legs to burrow around obstacles, each pair of legs acting to push and propel their bodies through in the earth. Marek and his team speculate that the exceptionally large number of legs of I. plenipes is a beneficial adaptation for subterranean tunnelling and possibly for clinging to the undersides of the sandstone boulders found exclusively in its habitat.

The aforementioned sticky, silk-like secretions may help to adhere them to the boulders and perhaps act as a defence mechanism that clears bacteria off the millipedes’ bodies.

Illacme plenipes legs
Scanning electron micrograph of Illacme plenipes
showing the millipede's four legs per segment.
Credit: Paul Marek et. al.
The diet of I. plenipes remains a mystery. Given the shape of the mouth accessories, the typical millipede diet in which decaying organic matter is mechanically fragmented is unlikely for the species. Instead it indicates a water or nutrient-poor diet.

I. plenipes Conservation Status
Although not officially assessed, Marek and his team believe the future of the species is bleak, as the constant development is destroying its limited habitat and apparently low population numbers. His team's attempts to breed the species in laboratory conditions remain fruitless.

He believes that the species may go extinct over the next years if no measures are taken for its protection.

Female specimen

I. plenipes Interesting Facts
- Its name means "the acme of plentiful legs"
- DNA analysis has revealed that its closest living relative is the Nematozonium filum which lives in Africa. The two species’ ancestors apparently split apart sometime after the breakup of Pangea, more than 200 million years ago.

References & Further Reading
Marek PE, & Bond JE (2006). Biodiversity hotspots: rediscovery of the world's leggiest animal. Nature, 441 (7094) PMID: 16760967
- Marek, P., Shear, W., & Bond, J. (2012). A redescription of the leggiest animal, the millipede Illacme plenipes, with notes on its natural history and biogeography (Diplopoda, Siphonophorida, Siphonorhinidae) ZooKeys, 241, 77-112 DOI: 10.3897/zookeys.241.3831
- O. F. Cook & H. F. Loomis (1928). "Millipedes of the order Colobognatha, with descriptions of six new genera and type species, from Arizona and California". Proceedings of the United States National Museum 72 (18): 1–26, f. 1–6, pls. 1–2.

Thursday, 27 March 2014

Orangutan goes spearfishing

Just came across this extraordinary photo, taken by Gerd Schuster co-author of Thinkers of the Jungle: The Orangutan Report, showing an orangutan spearfishing in Borneo.

Apparently, the orangutan had witnessed some of the locals fishing with spears and attempted to do the same, albeit with not much success. Monkey see, monkey do..

The description of the photo in the book reads:

"…a male orangutan, clinging precariously to overhanging branches, flails the water with a pole, trying desperately to spear a passing fish…

The extraordinary image, a world exclusive, was taken in Borneo on the island of Kaja… 

This individual had seen locals fishing with spears on the Gohong River. Although the method required too much skill for him to master, he was later able to improvise by using the pole to catch fish already trapped in the locals’ fishing lines."

The book also reports that the orangutans were able to swim across a local river to get food. This is notable since it has been widely believed that orangutans can walk in water but can't swim.

Of course, this is not the first recorded incident of tool-use by Orangutans, or primates in general. The species was first observed using tools in the wild in 1982 - by anthropologist  Biruté Galdikas - in wild Bornean orangutans in the Tanjung Puting National Park.

In Borneo, there have been sightings of orangutans using handfuls of leaves as napkins to wipe their chins while orangutans in Sumatra have been seen to use leaves as gloves, helping them handle spiny fruits and branches, or as seat cushions in spiny trees. There have also been reports of individuals, both in captivity and in the wild, using tools held between the lips or teeth, rather than the hands. Orangutans in captivity have been taught to chip stone hand-axes.

- Galdikas, B. (1989). Orangutan tool use Science, 243 (4888), 152-152 DOI: 10.1126/science.2911726
- O'Malley RC, & McGrew WC (2000). Oral tool use by captive orangutans (Pongo pygmaeus). Folia primatologica; international journal of primatology, 71 (5), 334-41 PMID: 11093037
- Schaik, C., Fox, E., & Sitompul, A. (1996). Manufacture and use of tools in wild Sumatran orangutans Naturwissenschaften, 83 (4), 186-188 DOI: 10.1007/BF01143062
- van Schaik CP, Ancrenaz M, Borgen G, Galdikas B, Knott CD, Singleton I, Suzuki A, Utami SS, & Merrill M (2003). Orangutan cultures and the evolution of material culture. Science (New York, N.Y.), 299 (5603), 102-5 PMID: 12511649

Further Reading

Wednesday, 26 March 2014

Saiga antelope

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Genus: Saiga
Species: Saiga tatarica
Conservation Status: Critically Endangered
Common Name: Saiga antelope, Saiga

Saigas are nomadic animals, best known for their distinctive enlarged noses that hang down over their mouth. The species originally inhabited a vast area, covering the steppes and semi-desert regions of south-eastern Europe and Central Asia from the Precaspian steppes to Mongolia and western China. The species also lived in North America during the Pleistocene period.

At present, the one of the two surviving subspecies (S. t. tatarica) can be found in one location in Russia (steppes of the northwest Precaspian region) and three areas in Kazakhstan (the Ural, Ustiurt and Betpak-dala populations). The other (S. t. mongolica) can only be found in western Mongolia.

The species became extinct in China by the 1960s, and in Ukraine during the 18th century.

Saiga antelope Description
An average saiga stands 0.6–0.8 m (2 ft 0 in–2 ft 7 in) at the shoulder and has a weight of 36 to 63 kg (79 to 139 lb). Males are larger than females. Adult males have two almost vertical, semitranslucent horns which are ringed in the bottom sections.

Saigas are easily recognisable by their distinctive mobile proboscis, an  unusual, over-sized, flexible nose structure. The proboscis is believed to filter out airborne dust during the dry summer migrations and to enable cold air to be warmed before it enters the lungs during the winter.

They have long, thin legs and a slightly robust body. The tail is short and the eyes are large with a dark brown iris. 

During the summer, their coat is short and yellowish red on the back and neck. The coat takes a white colour and becomes thicker and longer during the winter, being about 70 percent thicker compared to the summer. The underbelly is light in colour throughout the year, and there is a small mane on the underside of their neck.

Not much is known about the average lifespan in the wild. One wild born specimen was about 10.5 years old when it died in captivity while there have been recorded to live up to 12 years in the wild. Females reach sexual maturity one year after birth and males after a year and 9 to 10 months.

They can reach speeds of up to 50 miles an hour (80 kilometres/hour) during their long migrations.

Newborn saiga

Saiga antelope Behaviour & Reproduction
They are diurnal, migratory and nomadic animals that form large herds.

They undertake seasonal migrations in large groups from summer pastures in steppe grassland to winter pastures in desert areas, being able to cover considerable distances (exceeding 72 miles/day). They can swim across rivers, but they avoid steep or rugged areas.

The rut begins late in November when males fight for the possession of females. During this period, the noses of males swell up while the hair tufts below their eyes are covered in a sticky secretion. Males don't feed much during rutting and continuously take part in violent fights and often deadly fights. Up to 90 % of males may die during this time, with most casualties occurring from exhaustion. The surviving winners lead "harems", consisting of 5 to 50 females.

At the end of April, females give birth to usually two youngs  (2/3 ratio). When born, they have an average weight of 3,5 kg (~7.7 lbs).  All females of the herd give birth within a week of each other. The calves are initially concealed in vegetation. The herd begins to disperse into smaller herds, once the calves are a few days old. The smaller groups then head northwards to the summer feeding grounds. Then, the small groups break off, to reform once again for the journey to come next autumn.  It takes about  2.5 to 4 months for the calves to wean.

The gestation period lasts about 140 to 150 days. In captivity, young saigas have been recorded to occasionally nurse from unrelated adults, however, this has never been observed in the wild.

Male saiga antelope
Male saiga antelope

Saiga antelope Diet
They are herbivore animals, grazing on more than one hundred different plant species, with the most important being grasses, prostrate summer cypress, saltworts, fobs, sagebrush, and steppe lichens

Saiga antelope Predators
Wolves are the main natural predator of adult and new born saigas. Foxes and stray dogs prey on newborn calves.

Female Saiga tatarica
Female Saiga

Saiga antelope Conservation Status and Threats
Their overall population has experienced a major decline of over 80%, during the last decades and the decline is continuing. In the 1996, the species was listed as Vulnerable by the IUCN whereas today -since 2007- the species is classified as Critically Endangered.

Uncontrolled illegal hunting for horns (which are exported for traditional medicine in China) and meat since the break-up of the USSR, selective hunting of young males (with the subsequent distortion of the sex ratio) and poaching in general have resulted in a significant reduction of their numbers. 

Another major threat is the destruction of key habitats and traditional migration routes. 

In some areas, agricultural abandonment is also a problem. Specifically, cattle grazing formerly maintained the grassy species but land abandonment allowed another species (Stippa sp.) to intrude, which the Saiga cannot eat. 

Droughts, severe winters, diseases and natural predation from wolves also put some pressure on the population, however their contribution on the overall decline is minimal.

The population of the S. t. tatarica subspecies was estimated to be around 50,000 in 2003, down from around 1,250,000 in the mid-70s. Most individuals are found in Kazakhstan (decline from about 1,000,000 to 30,000 in 2003). The Mongolian population is estimated at around 1,500 individuals.

Video about the declining populations of Saiga

Conservation Measures
In 1990, "The Saiga Conservation Alliance" was established, a network of researchers and conservationists working to study and protect the now critically endangered Saiga Antelope and its habitat. 

The Mongolian Saiga subspecies has been legally protected since 1930. Two protected areas, Sharga NR (286,900 ha) and Mankhan NR (30,000 ha), were designated in 1993 to protect most of the remaining areas of occurrence.

The organisation "Rewilding Europe" has plans for reintroducing saiga to Europe.

The Kazakhstan government has allocated substantial funding to anti-poaching patrols and aerial surveys, and has passed legislation that strengthens rangers' powers of arrest. The Russian government has issued a order for emergency measures for the species conservation in Kalmykia, and also funds annual population surveys.

A successful captive breeding herd has been established at the Centre for the Study and Conservation of Wild Animals in Kalmykia. Hopefully, the research carried out there will be used to set up similar captive herds in other areas of the species’ natural habitat.

Saiga antelope In Captivity
There are currently two zoos where you can see a Saiga:
  • Moscow Zoo, in Moscow, Russia 
  • Askania-Nova,  in  Kherson Oblast, Ukraine

Saiga antelope intresting facts
- This strange ungulate species proved to be a problem for early taxonomists. Its true phylogenetic position is still debated.  When it was first named in 1766, the animal was placed in the genus Capra along with goats, later it was moved to the genus Antilope, and then to Gazella
Despite their common name, they are thought to be an intermediate species between antelope and sheep.
- The Saiga was protected in former Soviet Union and was the subject of several conservation programmes. This is why the population reached almost one million individuals and this is why the numbers started to greatly decline after its dissolution.

Male Saiga tatarica

References & Further Reading & Useful links
Arylov, Y., Badmaev, V., Bekenov, A., Chimeg, J., Entwistle, A., Grachev, Y. A., Lhagvasuren, B., Lushchekina, A., Mallon, D., Milner-Gulland, E. J. and Ukrainsky, V. 2004. The saiga antelope – teetering on the brink but still cause for hope. Oryx 38(3): 250–251.
- Milner-Gulland., Kholodova., Bekenov., Bukreeva., Grachev., Amgalan., & Lushchekina. (2001). Dramatic declines in saiga antelope populations Oryx, 35 (4), 340-345 DOI: 10.1046/j.1365-3008.2001.00202.x
- Bekenov, A., Grachev, I., & Milner-Gulland, E. (1998). The ecology and management of the Saiga antelope in Kazakhstan Mammal Review, 28 (1), 1-52 DOI: 10.1046/j.1365-2907.1998.281024.x

- Rubin, E., & Michelson, K. (1994). Nursing behavior in dam-reared Russian saiga (Saiga tatarica tatarica) at the San Diego wild animal park Zoo Biology, 13 (4), 309-314 DOI: 10.1002/zoo.1430130404
- Hashiguchi K, Hashimoto K, & Akao M (2001). Morphological character of crystalline components present in saiga horn. Okajimas folia anatomica Japonica, 78 (1), 43-8 PMID: 11552290
- Young, J., Murray, K., Strindberg, S., Buuveibaatar, B., & Berger, J. (2010). Population estimates of Endangered Mongolian saiga Saiga tatarica mongolica: implications for effective monitoring and population recovery Oryx, 44 (02) DOI: 10.1017/S0030605309990858
- Saiga antelope playlist video (youtube)

Tuesday, 11 March 2014

Royal Penguins - Amazing Video by BBC

I just stumbled upon a short but amazing BBC clip. The video is all about the annual visits that elephant seals and royal penguins pay to the MacQuarie Island,Tasmania for breeding purposes. The last 60 seconds really blew my mind. Enjoy:

The clip comes from BBC series South Pacific (Wild Pacific in the US).

Thursday, 6 March 2014

Giraffe Weevil (Trachelophorus giraffa)

image showing a Giraffe weevil
Giraffe weevil
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Attelabidae
Genus: Trachelophorus
Species: Trachelophorus giraffa
Conservation Status: Not assessed
Common Name: Giraffe weevil, leaf-rolling weevils (used for all Attelabidae species)

The giraffe weevil is a weevil species endemic to the forests of Madagascar. It was discovered in 2008, hence little is known about it. As you have probably guessed, its named this way due to having an extended neck, much like giraffes do.

Giraffe weevil Description
The giraffe weevil is sexually dimorphic, meaning that there is a great phenotypic difference between males and females of the same species. Specifically, males have a neck that is 2 to 3 times longer than their female counterparts. The extended neck is an adaptation that is used for intraspecific combat and nest building.

Males have a length of almost an inch (2.5 cm), making them one of the longest Attelabidae species.

Most of their body is black, except for their distinctive red elytra that cover their wings. The species is capable of flight.

Giraffe weevil Diet
They are herbivore insects, with adults feeding on a tree that is commonly known as the "giraffe beetle tree"
(Dichaetanthera arborea). They spend most of their lives on these small trees, venturing far from them only on rare occasions.

They are peaceful insects, showing no aggression towards other species.

Video showing a Giraffe Weevil

Giraffe weevil Reproduction
Males use their long necks to fight with other males to win the right to mate with a nearby female. They use them as a weapon to push and wrestle with the opponent.

The winner then mates with the female. The female then secures a leaf - from Dichaetanthera arborea - and uses it to build a cigar-like nest. To do so, she will fold and curl it multiple times. Then, she lays a single egg inside the leaf. Finally, she snips the leaf  from the plant, which falls to the forest floor. The leaf will provides sustenance to the newly-hatched larvae during its first days of life.

This leaf-rolling behaviour is not unique to the giraffe weevil, its something all Attelabidae species do and this is why they are commonly known as the leaf-rolling weevils.

It is rare for males to kill each other during courtship. Most of the times, the loser simply retreats.

Video showing the reproduction habits of the Giraffe Weevil 

Conservation Status
Due to its recent discovery, the species conservation status has yet to be assessed. However, their population is believed  to be healthy and not threatened by human activity.

They have no known predators, although it is suspected that the eggs may be occasionally eaten by smaller bugs.

Giraffe weevil Interesting Facts
- Despite their somewhat frightening appearance, they are not dangerous to humans
- Lasiorynchus barbicornis is an unrelated species from New Zealand that is also called Giraffe weevil

Image of Lasiorynchus barbicornis
The unrelated Lasiorynchus barbicornis
References & Further Reading
- Legalov, A. A. (2004). New data of the leaf-rolling weevils (Coleoptera: Rhynchitidae, Attelabidae) of the world fauna with description of 35 new taxons. Baltic Journal of Coleopterology
- Kobayashi, C., Okuyama, Y., Kawazoe, K., & Kato, M. (2012). The evolutionary history of maternal plant-manipulation and larval feeding behaviours in attelabid weevils (Coleoptera; Curculionoidea) Molecular Phylogenetics and Evolution, 64 (2), 318-330 DOI: 10.1016/j.ympev.2012.04.006
- Giraffe Weevil Youtube Search

Monday, 3 March 2014

Promachoteuthis sulcus - The squid with the human like teeth

Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Teuthida
Family: Promachoteuthidae
Genus: Promachoteuthis
Species: Promachoteuthis sulcus
Conservation Status: Unknown
Common Names: The squid with human teeth

This weird, alien looking creature is called Promachoteuthis sulcus. It is a rare, newly discovered deep-sea squid, best known for its human-like mouth. The species is only known by one specimen that was caught in 2007, in the nets of the German research vessel "Walther Herwig", near the Tristan Da Cunha islands, at a depth of 1,750 to 2,000 m (5,740–6,560 ft).

Don't be frightened by its appearance. It's barely one inch long! As for the human like-teeth.. Well, they are actually lips!
image showing the Walther Herwig research vessel
The Walther Herwig research vessel 

Promachoteuthis Sulcus Description
As aforementioned, the little knowledge we have for the species comes from a single, immature female, 25 mm long specimen.

P.sulcus ventrolateral view
Image of the P.sulcus specimen - ventrolateral view 

It has eight arms, two large tentacles, and what looks like to be a mouth with human-like teeth. The species is distinguished from related taxa on the basis of several morphological features, including:
  • Nuchal fusion between the head and mantle 
  • Arm suckers are way larger compared to club suckers 
  • Greater width of tentacle base than arm base 
  • A recessed club base 
  • The presence of an aboral tentacle groove

P.sulcus dorsal and ventral view sketch
P.sulcus drawing -  dorsal and ventral view

For more info and close up images of the various body accessories (head, arms, tentacles etc) please use the first link in the references section.

About the Teeth
Squids often have tough, razor-sharp beaks that they use to chop and chew their prey. P. Sulcus is no exception. As for the creepy teeth, they are actually circular, folded lips, with only the upper and lower portions visible. The beak lurks just behind them.

A close up of the p. sulcus mouth
Mouth close-up 

Promachoteuthis sulcus Interesting Facts
The creature has gained a small following as an internet meme, for obvious reasons.

References & Further Reading
- Young, Richard E. and Michael Vecchione. 2007. Promachoteuthis sulcus Young, Vecchione and Roper, 2007. Version 15 November 2007. in The Tree of Life Web Project
- Young, R., Vecchione, M., & Roper, C. (2007). A new genus and three new species of decapodiform cephalopods (Mollusca: Cephalopoda) Reviews in Fish Biology and Fisheries, 17 (2-3), 353-365 DOI: 10.1007/s11160-007-9044-z