Trench Warfare !

SHINDERJEET KAUR — Fri, 21 Mar 2008 06:36:00 GMT

If you thought Trench Warfare was a military tactic of the French and Germans of the past, you might want to you might want to reassess this hasty conclusion. A species of ants, known as the Allomerus decemarticulatus employs a somewhat similar tactic to catch its prey. These ants are masters in taking cover in the ground and setting up the ideal trap which is extremely successful in luring insects of a much bigger size than themselves. To find out the details of their master “torture” plan and of how they deceive their unsuspecting victims, have a look at the links at the end of this short write-up and the images provided should help you better visualize this unique and indeed ingenious method of feeding. Here is a quick summary of their grand plan:

Using plant fibers and fungus, the ants engineer the perfect trap.
They leave holes in the trap, big enough to poke their heads through.
Its victim happens to land at this strategic spot.
It finds its legs or antennas, or anything that the ants can grab being pulled and torn from it. This causes the victim impairment or even death.
The ants in this colony, have earned themselves a meal and will carve out their winning which they will share amongst themselves.
Here’s a limiting factor to their tactic though, the victim’s legs, hands or antennas have to be able to fit into these holes to for the plan to be successful.

I find this article particularly interesting because it is relevant to the topic of cooperative hunting we saw in the Harris Hawks as discussed in lecture. Because these ants work in a colony, they are able to feed on such a large insect which would otherwise not be possible if they were to attempt this feat alone.In fact, there is no doubt that the prey they caught collectively could be a predator if not for this method of kill.Pretty interesting reversals of prey and predator !

Besides that, the articles also mention that these ants work in a hierarchy of which we encountered during lecture again. Apparently, the oldest ants in the colony will do the work of trap building. It must come from experience that they are chosen to carry out this critical task. Any loopholes will evidently result in a failed plan which the ants overcome with the division of labor.. The younger ants will learn from their elders and the tradition will then pass down the successive generations. Reminds us a little about the archer fish too with regards to learning the exact positing from which it should sprout water and get its prey !

In sum, these articles have highlighted both feeding and predatory behavior and the importance of hierarchy in ants.

Ants; traps; torture; prey; cooperative hunting; feeding; colony; hierarchy; division of labor; group30

References

Amazing Ants Ambush Prey from Foxholes

By Robert Roy Britt, LiveScience Senior Writer ,20 April 2005

http://www.livescience.com/animals/050420_ant_trap.html

Fierce ants build 'torture rack', 23 April 2005

http://news.bbc.co.uk/2/hi/science/nature/4472521.stm

"Torture Racks" Are First Known Traps Made by Ants, James Owen, 20 April 2005

http://news.nationalgeographic.com/news/2005/04/0420_050420_ant_trap.html

The Stinging Sailor

LIAU QINGYE EILEEN — Fri, 21 Mar 2008 06:10:00 GMT

Now, what could this be?

a) An inflatable float.

b) A breathing apparatus.

c) A Jellyfish.

Answer: d) None of the above.

What this inflatable jellyfish like animal is an invertebrate, the Man- of –war. It does have a rather impressive name, but IS IT impressive?

As I have found out from this article, it is indeed extraordinary.

The Man- of – war is not exactly ONE animal, but is actually a floating hydrozoan, which consists of four types of polyps. The four different simple animals that form the Man- of – war are the float, the tentacles, the feeding zooids and the gonozooids which produce gametes for reproduction.

Click here for more information on polyps.

These different polyps work together to form an intelligence system that functions as a whole. Each polyp has a different function, which helps in the survival of the Man- of – war. For example, the float polyp helps in the locomotion of the Man- of – war. It is like a sac filled with nitrogen, and acts as a “sail” to drift the animal in the direction of the wind and tide. This is also where the Man- of – war derived its name from, as it resembles an olden day battle ship.

With all these different animals living “under the same roof”, one must wonder why they do so and how they do not feel a competition for resources.

Each polyp has different needs and functions. Other than the “sail”, one other part is for reproduction, while the remaining two parts function as the hunting and digesting tool.

Man- of – wars are hermaphrodites; each individual gonozooid consists of male and female parts. The fertilised egg develops into a planktonic larva which then reproduce in large quantity by asexual budding.

The most powerful part of this combined animal is the tentacles, not only do they contain a painful sting which can be fatal, they are also used to catch and trap small sea creatures which will then be slowly dissolved by enzymes secreted from the underside of the float.

As you can see, these four simple animals coexist as “one organism” because the benefit of doing so greatly outweighs the cost involved. Although a single animal has a function by itself, it will never be able to survive alone, as it lacks other necessary functions for survival.

I find this animal really amazing because it has managed to survive even without doing much. There’s no need to swim as the “sail” helps in drifting. Eating for this animal is also like a simple task as it simply traps and dissolves its prey; absolutely no need for foraging or stalking. In addition, there is no need for MATE- SELECTION, a process which many other animals spend alot of time and energy engaging in.

At this point, we wonder what could possibly lead any fish to swim through the deadly tentacles of the Man-of –war.

The answer?

The Nomeus gronovii.

This fish shares a symbiotic life with the Man-of-war.

Want to see the Man- of- war in action?

Man-Of-War Podcast!

Remember to look out for the Man-of –war fish, as well as the enemies of the Man-of-war.

Here's some trivia:

As compared to a jellyfish, the man-of-war is a giant.

As compared to a grown man...

it STILL is a giant!!

See also:
Man Of War Fact-file
Team Transformation Rule 2: Cultivate Team Intelligence
What to do when you get stung by a Man-Of-War??

Reference:
Websites:
Kurlansky, Mindy B. (2002). Physalia physalis. Retrieved March 20, 2008, from Animal Diversity Web Web site: http://animaldiversity.ummz.umich.edu/site/accounts/information/Physalia_physalis.html

Polyp. (2008, March 17). In Wikipedia, The Free Encyclopedia. Retrieved March 21, 2008, from http://en.wikipedia.org/w/index.php?title=Polyp&oldid=198944134

Portuguese Man-of-war. In National Geographic. Retrieved March 20, 2008, from http://animals.nationalgeographic.com/animals/invertebrates/portuguese-man-of-war.html

Pictures:
Man-of-War Fish - Nomeus gronovii. In thejump.net. Retrieved March 20, 2008, from http://www.thejump.net/id/man-of-war-fish.htm

Portuguese Man-of-war. In aloha.com. Retrieved March 21, 2008, from www.aloha.com/~lifeguards/portugue.html

Nomeus gronovii- Man-of-war fish. In FishBase. Retrieved March 21, 2008, from http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=2461

Video:
Portuguese man-of-war. In National Geographic. Retrieved March 20, 2008, from http://podcastmedia.nationalgeographic.com/ngvideos/pc62_PortugueseManowar.mp4

LSM1303 Animal Behaviour Student Blog : colony

Trench Warfare !

The Stinging Sailor