Saturday, 22 November 2014

Hammerhead Slug: World's Largest Flatworm

Bipalium kewense, the weird hammerhead slug
Bipalium kewense
Notice the distinctive hammer-like head
By Ajaykuyiloor (Own work) [CC-BY-SA-3.0],
via Wikimedia Commons
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Turbellaria
Order: Tricladida
Suborder: Continenticola
Family: Geoplanidae
Subfamily: Bipaliinae
Genus: Bipalium
Species: Bipalium kewense
Common Names: Hammerhead slug, Greenhouse Planarian

Nicknamed as the "hammerhead slug" due to its half-moon shaped head, Bipalium kewense is not your everyday flat worm. Not only does it hold the record for world's largest flatworm but it's also one of the few flatworms that live on land. Oh, did I mention that it defecates from its mouth?

Distribution & Habitat
The hammerhead slug is believed to originate from Southeast Asia. However, it appears that the species has become cosmopolitan with recordings coming from many different tropical and subtropical countries. It's especially common in greenhouses, thus its second common name, the "greenhouse planarian".

The species has been found spanning the entire southern portion of North America. Verified recordings include:
  • Encanto, California 
  • Jersey City, New Jersey 
  • Nashua, New Hampshire 
  • New Orleans & Baton Rouge, Louisiana 
  • Puerto Rico, near Silver Springs 
  • Savannah, Georgia 
  • Urbana, Ohio 
  • Washington DC

Bipalium kewense is also common in the Hawaiian Islands and in the tropical parts of South America. It has also been sighted in the UK, China, Japan, New Zealand and many other countries. This widespread occurrence is the result of horticultural practices, mainly the commercial dispersion of potted plants.

Like earthworms, hammerhead slugs prefer to burrow in moist soil.


Description
Fully mature adults routinely reach 40 cm (10 in) in length, with the maximum recorded length being about 60 cm (23 in). The body is covered by a layer of mucus that prevents it from losing too much water to the environment. The mucus is also important for locomotion.

They usually come in dark colors, like gray, brown and black and have two distinctive dorsal stripes that run the length of the body.

One of the species' weirdest traits is the half-moon shaped head. The mouth is located mid-way down the body (on the ventral side) which also serves as the.. anus since they don't have one. Yum! They also have no respiratory and circulatory system, skeleton and legs.

Hammerhead slug (Bipalium kewense) in Hawai
Hammerhead slug, crossing a road near Hilo, Hawaii.
By Dick Culbert from Gibsons, B.C., Canada (Bipalium kewense, a Hammerhead Worm.) [CC-BY-2.0], via Wikimedia Commons

Diet
The Hammerhead slug is predatory, primarily feeding on earthworms although it will turn to cannibalism when food is scarce. The species dietary patterns have not been extensively studied, and it possibly feeds on other organisms, like slugs and insect larvae.

To eat, it will follow trails left behind by earthworms until it finds one. When prey is caught, it will lay atop of it, as the sticky slime helps to hold it down to the soil. Then it protrudes its pharynx and sucks out the body fluid of the earthworm. Surely, not a good way to die..


Hammerhead slug attacking an earthworm

Reproduction
Bipalium kewense is hermaphroditic (like all Bipalium species) and capable of both asexual and sexual reproduction. However, the latter has rarely been observed and apparently fragmentation is the preffered form of reproduction.

This is done by chipping off about 1cm of the tail. The tip first attaches itself to something in the soil, and then the parent worm pulls away. The new worm can move immediately and develops a head within 10 days.

As for sexual reproduction, they lay eggs in a bright red cocoon. After one day the cocoon turns black and the eggs hatch about 20 days later, depending on temperature and moisture conditions.


Is it dangerous?
Over half of all known flatworm species (Platyhelminthes) are parasitic and some do enormous harm to humans and their livestock. However, this is not the case with the majority of the flatworms in the Turbellaria class, including B. kewense.

Production of Tetrodotoxin  
Tetrodotoxin (or TTX) is a potent neurotoxin that among others induces paralysis. Recent research revealed that Bipalium kewense and the closely related B. adventitium have small amounts of it in their body, most probably used during predation to subdue large prey items. As of 2014, they remain the only known terrestrial invertebrates capable of producing this toxin.

Interesting and Weird Facts Sum-Up
- Half-moon shaped head
- Mouth also serves as anus
- All individuals are hermaphroditic and capable of sexual and asexual reproduction. They usually reproduce by chipping a small part of the tail
- It is considered a pest to farmers because they predate on earthworms
- Non-parasitic, harmless to humans
- Along with the closely related B adventitium, the only known terrestrial invertebrate to produce the Tetrodotoxin toxin

Wednesday, 19 November 2014

Video: Seals Caught Raping Penguins !

Seal forcefully coerces with penguin
Someone's having a really bad day!
In a study published a few days ago, researchers from the Mammal Research Institute at the University of Pretoria, South Africa reported three incidents of fur seals (Aptenodytes patagonicus) sexually harassing and coercing with king penguins!

The authors even took footage of the large mammals forcefully putting the birds to the ground and attempting to mate with them! The incidents took place at the sub-Antarctic Marion Island, on Goodhope Bay and Funk beach.

These observations are similar to a previously published observation (2006) that occurred in the same island on Trypot beach. All four incidents followed a similar pattern. The male seal first chases, captures and mounts the penguin and then "attempts copulation several times with periods of rest in between".


Seal having sex with penguin #1

In three of these incidents the penguins were released relatively unharmed (although one was bleeding from the cloaca due to penetration) but the fourth got really, really unlucky. It was killed and then eaten by the seal. This may have been because unlike the others he was "energetically opposing the seal’s actions".

The incidents lasted anywhere from 10 to a whooping 85 minutes!

"Honestly I did not expect that follow up sightings of a similar nature to that 2006 one would ever be made again, and certainly not on multiple occasions." said Nico de Bruyn, one of the authors, to BBC.

Why fur seals are engaging in these bizarre sexual activities is puzzling. Initially it was hypothesized that "the sexual coercion event [in 2006] was a result of the seal’s predatory behavior towards the penguin being redirected into sexual arousal". But in the 2011 incident, the seal was killed and eaten which makes this hypothesis less plausible.

For now the most prevailing theory is that the whole sex with penguins thing has become a learned behaviour. But how did this behavior originally begin still remains a mystery.

"Determining the drivers of the unusual bebehaviorescribed here is nearly impossible.", an extract from the stydy.

Seal having sex with penguin #2



Notes
- The paper and videos are available for free at Springer.com


References
- de Bruyn, P., Tosh, C., & Bester, M. (2008). Sexual harassment of a king penguin by an Antarctic fur seal Journal of Ethology, 26 (2), 295-297 DOI: 10.1007/s10164-007-0073-9
- Haddad, W., Reisinger, R., Scott, T., Bester, M., & de Bruyn, P. (2014). Multiple occurrences of king penguin (Aptenodytes patagonicus) sexual harassment by Antarctic fur seals (Arctocephalus gazella) Polar Biology DOI: 10.1007/s00300-014-1618-3

Sunday, 16 November 2014

Sunday's Nudibranch: Ardeadoris cruenta

Ardeadoris cruenta, red spots visible
Ardeadoris cruenta
By Chad Ordelheide (Own work), [CC-BY-SA-3.0],
via Wikimedia Commons
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Doridoidea
Family: Chromodorididae
Genus: Ardeadoris
Species: Ardeadoris cruenta (Synonym: Glossodoris cruenta)

Ardeadoris cruenta is a beautiful and colorful nudibranch that occurs in the tropical Western Pacific Ocean. Sightings are relatively rare and the species has been recorded in Queensland of Australia, the Lembeh Straits in northern Sulawesi and the Solomon Islands in Oceania.

The genus name "cruenta" is derived from the feminine form of the Latin "cruentus", which means "stained with blood", a reference to the distinctive red spots on its upper dorsum. It has a pale-lemon colored body with a bright yellow and white lined frilly mantle and foot.

By Heike Wägele & Annette Klussmann-Kolb
[CC-BY-2.0], via Wikimedia Commons

The red dots follow a circular pattern on its dorsum next to the mantle edge. Both the rhinophores (the antennae-like structures) and gills have the same pale-lemon color as its body, although there is some color variation among individuals. Adults reach a length of at least 5 cm (~2 in).

A. cruenta looks very similar with Ardeadoris rubroannulata, however the two are easily distinguished by the latter's lack of red spots.

Like many nudibranchs, it feeds on sponges.


 Ardeadoris cruenta Video

Photographer: Crawl_ray
[CC BY-SA 3.0]
Photographer: Crawl_ray
[CC BY-SA 3.0]
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Saturday, 15 November 2014

7 Strange Two-Headed Animals

Two-headed animals are the saddest, weirdest and for some the most intriguing "wonders" of nature. Polycephaly is a greek-derived term, from the words "πολύ" meaning "multiple" and "κεφάλι" meaning "head". There is also a variation of the condition, diprosopus, in which the animal has two faces on a single head.

Here is a collection of some of the weirdest two-headed animals you can find on the internet:

1. Frankenlouie the cat with two faces


First we have Frankenenlouie, a cat with the diprosopus condition. Frankenlouie was born with two faces, three eyes, two noses and two mouths. What's so interesting about this cat is its remarkable longegivity. Most diprosopus cats die within a matter of days or months after their birth. According to the last update I could find on Frankenenlouie, the cat lived to be at least 12 years old. Who knows, it may still be alive!

2. Albino snake with two heads



This snake(s) is truly one in a billion, maybe more. Two-headness and albinism, all in the same package. How efficient! As you can see from the title of the video, it can be yours for 50,000$

3. Two headed turtle 



Meet Thelma and Louise, a two headed turtle born last year at the San Antonio Zoo. The turtle was born "healthy" and  had no problems with walking and swimming. Unfortunately, she is no longer with us. On July 29, 2014 officials announced that it died due to unknown reasons.

4. Two headed calf



This poor animal was born three years ago, in a small village in western Georgia. The mother refused to allow her strange offspring to suckle and as a result the owners had to bottle-feed it to keep it alive. Apparently it has one personality as everything is shared. When the right head suckles the left head is making the same suckling action. When one head blinks, so does the other. There has been no update on the calve's status.

5. Two headed dolphin 

Dolphin with two heads

The two-headed dolphin you see in the image was discovered by a tourist in the city of Izmir, Turkey and is only the fifth recorded case of conjoined twins in the dolphin family. Click here to learn more about the story.

6. Two headed pig


This is Rudy, a two-headed pig born in the farm of Scott and Vicki Vorwald in Iowa in 1998.  It was purchased from its owner for $5,000 by Los Angeles-based animal rescue group "Pigs Without Partners", who renamed it Ditto. Rudi died in the same year, just two months after getting to its new home. 

7. Two headed bearded dragon 



This is Bert and Ernie, a two-headed bearded dragon. At the second video they are two months old. The owner who comes by the nickname "Valley DragonRanch" sold Bert and Ernie to The Venice Freak Show in California. The transaction took place in 2009

And finally some honorable mentions:

1. Triple Headed Frog


This three-headed amphibian was discovered in Weston Super Mare, England 2004. It was found near a nursery and was kept in a container for several hours but hopped away to freedom later while nursery staff were showing it to curious parents.

2. Two headed dogs made in Russia


Two-headed dogs can occur naturally but Soviet scientist Vladimir Demikhov actually created two headed dogs via dog-head transplantation. He also did several similar transplantations in the 1930s and 1950s, lung and heart transplantation.

It should be noted that his work on dogs and other animals is considered by many as pioneering, contributing in the long run in the saving of thousands of lives.  For instance, Christiaan Barnard, who performed the world's first heart transplant operation from one person to another person in 1967, twice visited the Demikhov's laboratory in 1960 and 1963 and he considered Demikhov as his teacher. But even with this in mind, I still feel very sick watching the video.

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  • Octogoat: The story of Octogoat, a goat born with 8 legs
  • Cy: Cy, short for cyclops, was a kitten born with one eye and no nose

A two headed calve at the Museum of Lausanne.
Credit: By Rama (Own work) [CC-BY-SA-2.0]
via Wikimedia Commons

Wednesday, 12 November 2014

Zooborn Pangolin Video That Will Melt Your Heart

Super cute pangolin baby from Taiwan
Meet Gung-Wu, a cute baby pangolin born on 9/30/2014, in Taipei Zoo, Taiwan. Gung-wu was born healthy but it had problems breast-feeding its mother and soon its weight dropped from 133 to 113 grams.

On October 2, the zookeepers began hand-feeding it artificially using a pipette. For now all appears to go well and the cub will most probably have a full and healthy life.




This is the latest update given by the zoo on a YouTube comment four days ago:
"Failed to work with her mother for feeding, the keepers took her away for bottle feeding. Starting from hourly feeding, her weights came up to 313g from 113g. Now she is used to be feed every 4 hours, a little pat on the back, special shower treatment, a little explore as exercise, arm climbing as she should do naturally with her mom to move around, she will roll herself up and becomes a ball to sound sleep."

Monday, 10 November 2014

The Dancing Kiwa Puravida (Yeti Crab)

Kiwa Purevida, one of the three yeti crab species
Kiwa Puravida
Credit: Andrew Thurber
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Malacostraca
Order: Decapoda
Infraorder: Anomura
Family: Kiwaidae
Genus: Kiwa
Species: Kiwa puravida
Conservation Status: Not assessed
Common Name: Yeti crab

Meet Kiwa puravida, a recently discovered deep-sea dwelling decapod and one of three species informally known as "yeti crabs". The other two are Kiwa hirsuta and a creature commonly known as the "Hoff crab" which has yet to be described.

What is most interesting about this species is that individuals "dance" in unison to cultivate their own food! Wait...Whaaat? Keep on reading!

Discovery
The species was discovered in June 2006, during a geological research cruise off the coast of Costa Rica, which aimed to study the ocean floor that belches out methane and hydrogen sulphide gas. Head of the expedition was Andrew Thurber, marine ecologist and now Assistant Professor at the Oregon State University.

While exploring the ocean floor Gavin Eppard, pilot of the submarine, noticed dozens of smalls crabs rhythmically waving their claws over active methane seeps and decided to collect one.

"He came up and just handed me this new species." said Thurber.

The discovery was made on a depth of about 1.000 meters (~3.280 ft).

The area where Kiwa Purevida was discovered
The area where K. Puravida was discovered

Description
K. puravida and the other two yeti crab species are called this way due to the white, hair-like bristles that cover their claws and body. The bristles are full of symbiotic bacteria, which derive energy from the inorganic gases expelled by the seeps. The species is blind.

The female specimens collected to date had a carapace length between 4.9 and 24.5 mm, whereas collected males had a carapace length ranging from 7.4 to 38.6 mm.

Overall, K. puravida looks a lot like K. hirsuta, but differs in it at least ten anatomical features. The range of occurrence of the two species is about 6500 km away and the two occur in different habitats and depths. K. puravida was collected from a methane seep at 1000 meters deep whereas K. hirsuta was observed and collected at a greater depth (more than 2200 meters), next to a hydrothermal vent.

Kiwa Puravida specimen
Credit: Andrew Thurber

Diet
K. Puravida  feeds on the symbiotic bacteria, using comb-like mouthparts to harvest them from its bristles. In turn, these bacteria metabolise the hydrogen sulfide and methane produced by the seeps to feed themselves.

"It looks like the bacteria may use the seeps as stepping stones, to create this global connected population that consumes the energy coming out of seeps and vents." said Thurber.

Among other deep-sea creatures that make use of such symbionts, K. Puravida is unique in that it appears to actively wave its appendages over the vents in order to provide the bacteria with more nutrients. Actually, the crabs wave their claws in unison, in what seems to be a rhythmic dancing-like performance. This rhythmic movement stirs up the water around the bacteria, ensuring that fresh supplies of oxygen and sulphide wash over them and helping them to grow.

You can see this rhythmic movement in the video down below:


00:02 to 00:15, yeti crab feeds from the bacteria on its claws and body
00:15 to 00:24 Kiwa puravida  demonstrating the rhythmic waiving of the chelipeds.
00:24 to 00:32 Two individuals performing either a courtship or competitive display


Carbon isotopes and fatty acids in the body of K. Puravida match organisms that get their nourishment without the sun’s energy, rather than those that rely on photosynthesis. This suggests that K. puravida's feeds exclusively or primarily on seep bacteria, rather than surrounding photosynthesizing plankton.

"We clearly showed that this species isn’t using energy from the sun as its main food source. It’s using chemical energy from the sea floor." said Thurber.


Behavior
Very little is known about the species' behavioral patterns. Thurber and his colleagues reported that the species demonstrates "intriguing intra-species interactions":

"An individual that appeared to have recently molted due to its minimal bacterial covering, began grappling with a larger specimen that it approached. This ended in a dominance display where the challenged individual forced the challenging individual off the carbonate outcropping while both individuals had their chelipeds spread apart. As decapods commonly reproduce after molting, as has also been observed in the hydrothermal vent S. crosnieri, the individual that was forced off may have been inseminated during this display or this may have been a behavior demonstrating how this species competes for space in areas of active seepage." extract from the study

Other Interesting Facts about  Kiwa Puravida
- Puravida derives from a Costa Rican Spanish saying (used to answer "How are you doing?" or to say "Thanks") and translates to "pure life". Thurber gave this name to pay homage to the place it was discovered.

Sunday, 9 November 2014

Sunday's Nudibranch: Jorunna funebris

Jorunna funebris, black and white nudibranch
 Jorunna funebris
Photo by © Mark Rosenstein  [CC BY-NC-SA 3.0]
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superfamily: Doridoidea
Family: Discodorididae
Genus: Jorunna
Species: Jorunna funebris
Common Name: Dotted nudibranch, Polka Dot

When I was writing my "14 Most Amazing Nudibranchs" post I had a really hard time choosing which species to include and which not.

This animal group is very diverse and full of beautiful, alien-like or simply weird looking creatures. One post can't make them enough justice.

So, from now on, every Sunday I will introduce you to a different species of nudibranch. Usually there is little research on individual species and as a result the posts will be short in information but rich in photos and images. Hope you enjoy them.

Today's nudibranch is Jorunna funebris which for some reason reminds me of Oreos.





Distribution & Habitat
The Dotted nudibranch occurs in the Red Sea and in the Indian Ocean along East Africa. It inhabits seagrass meadows, coral rubble, and coral reefs and can be found in depths ranging from 10 to at least 21 meters. 

Description
Adults have an oval body and are 2 to 6 cm long. They are easily identified by their white body and random black-brown spots, made of tiny tubercles which give them a fuzzy appearance.

The six, black-brown branched gills form a complete circle around the anus.

Credit: By Steve Childs from Lancaster, UK (Flickr)
[CC-BY-2.0], via Wikimedia Commons


Diet
The species has been recorded to feed on blue sponges (Neopetrosia sp.).

Reproduction
The Dotted nudibranch is a hermaphrodite that lays egg masses. .The genital openings lie on the right side of the body, so they have to position themselves side-by-side in opposite directions before mating.

 In captivity, the egg masses ranged from 17.1–48.0 cm in length, and between 0.4 cm and 0.7 cm in width. The density of egg capsules varied from 27–64 egg capsules/mm2 of egg mass with each egg capsule having 1 to 4 larvae inside.

Two Jorunna funebris having some sexy time
Mating Jorunna funebris
Credit: © Ria Tan, [CC BY-NC-SA 2.0]

More Photos and Videos

Purple Jorunna funebris
Credit: By Katia Ferrer
[CC-BY-SA-3.0], via Wikimedia Commons
Jorunna funebris (polka dot) nudibranch
Photo taken in Jorunna Funebris, Shark Island, Ko Tao, Thailand
Credit: By yeowatzup from Katlenburg-Lindau, Germany
[CC-BY-2.0], via Wikimedia Commons
Jorunna funebris in Thailand
Credit: Marine Life in the Koh Phangan vicinity, Thailand
[CC BY 3.0]
Beautiful Jorunna funebris (Lautem, East Timor)
Credit: Nick Hobgood, Location: Lautem, East Timor
[CC BY-NC 2.0]
Credit: Nick Hobgood
[CC BY-NC-SA 3.0]

Video shot in Sailrock, Thailand


Location:  Seth's Point, Kapota Island, Wakatobi, South East Sulawesi, Indonesia


Jorunna funebris feeding on blue sponges