Thursday, 12 January 2012

Pinta Island Tortoise

This week’s Epic Creature is one of (if not THE) rarest living animal on the planet today; there is only one known Pinta Island Tortoise (Chelonoidis nigra abingdoni) left alive. As far as we know, the only Pinta Tortoise left is a male – His name is Lonesome George. There is a reward of $10,000 offered by Darwin Station to whom ever finds a female to mate with George and save this species.

The Pinta Island Tortoise is a subspecies of the Galapagos Tortoise that evolved separately on the Pinta Island. A tortoise is a land dwelling reptile - this is what makes the tortoise different from the turtle. Turtles are amphibian (start their lives in water) whereas tortoises are land dwelling only. These tortoises are large, weighing about 400Kg(880lb) and reaching 1.8m(5.9ft) in length. They have four legs, a tail and a head on a long neck. The body of the tortoise is protected with a thick shell, which these creatures are very famous for.

Pinta Island tortoises are “keystone creatures”, meaning they eat vegetation and fruit on the island and defecate the seeds which helps the plant life cycle and allows  sustainable food for the tortoise. These tortoises started to become endangered because feral goats were introduced to the island and started devouring all the vegetation, not leaving enough for the tortoises to survive. The tortoises had not encountered such a problem before and did not have any adaption to help survive and they started dying.
Tortoises are also known to be able to live a very long time - Lonesome George is believed to be about 100 years old and is very healthy. The feral goats that destroyed most of the species have since been removed from the island and the vegetation has start to grow back, giving Lonesome George his food back and a chance to live a little longer.

Lonesome George has mated with other species of tortoise but they were not successful. If we cannot find a female for Lonesome George to mate with then this species of tortoise will finally become extinct.

This week’s creature is Epic because it is the rarest known creature on the planet (though I wish I were writing about it for a better reason.) I hope that sometime in the future Lonesome George can have the family he’s always dreamed of and I can scratch this creature off the list!

Thursday, 5 January 2012

Ophiocordyceps unilateralis

I know I have not posted in a while. I got lazy over the holidays and basically forgot to post so I will be back on track this year. So here is the first post of the New Year!

This creature is something straight out of science fiction – only it’s real! This is a creature that will infect an ant and alter its behavior, basically zombifying the ant and killing it to spread and infect more ants.

The Ophiocordyceps unilateralis is a parasitoid fungus (meaning it requires another living creature to live off of) that targets a specific host. This one targets the carpenter ant, though there are many different parasitoid fungi that target other insects as well. The ophiocordyceps unilateralis (I am going to call it the fungus from here on out as the name is too long) spores enter the ant’s body and begin to consume the non-vital soft tissue. Then the fungus begins the yeast stage of it development spreading in the ant’s body, which starts to affect the brain and change its behavior. Scientists are not sure how the fungus can do this but it basically highjacks the brain and makes the ant do what it wants. The fungus makes the ant climb up a plant and bite into it to hold itself there. The fungus makes the ant bite with abnormal strength leaving a telltale bell-shaped mark, there have been similar bite marks left in 48 million year old plant fossils suggesting these fungi have been around for 48 million years.

Now that the ant is where the fungus wants it, the fungus kills the ant and continues to invade the soft tissue more, fortifying the exoskeleton. The fungus continues to spread out of the ant’s body into the plant to fortify itself even more and when it is ready to reproduce it will grow a stem with a ball on it called a fruiting body out of the ants head. This will burst open and spread the spores of the fungus to infect more ants. This whole process will only take 4 to 10 days.

The ants always seem to bite into plants about 25cm off the ground with 94-95% humidity and a temperature of about 20°C to 30°C. When the fungus does not find the requirements it needs to grow it results in undersized or abnormal reproductive structures (fruiting bodies).

There you are, zombies are real. They are just not what you thought they would be - they only affect insects and in this case the carpenter ants. Too bad Shaun and Ed are not there to help save them.

Quite an Epic Creature to kick off the New Year with!