Comments on: Dishonest Crabs

By: Cheyennne G.

Cheyennne G. — Fri, 03 Sep 2010 16:08:00 +0000

I think this is a great post! very interesting and thought out. I never thought about this. Well I sort of did because my dog isn’t always honest but anyway great job on the post.

By: Joseph

Joseph — Fri, 12 Mar 2010 00:42:15 +0000

This is a really cool post. Fiddler crabs are interesting animals for many reasons. As the male grows to maturity, the relative weight of its large claw, or cheliped, changes from 2% to 65% of its total body weight. They are brown in color, with the front of the shell and eyestalks ranging from blue to turquoise. The large claw of the male is usually yellowish orange to yellowish white, and its walking legs are dark and banded. Here is more information on the fiddler crab: http://www.dnr.sc.gov/marine/mrri/acechar/specgal/fiddler.htm
There are many other animals that lie. One of them is the anglerfish. Dangling from a spine on the tip of its snout is a built-in fishing lure. When the angler fish is hungry, it searches around for prey and dangles around its “bait” so it looks like a fish swimming. When the anglerfish’s prey comes by to get the “bait”, it eats it.
Besides the dangler fish, there are animals that fake other animals in courtship rituals. For example a certain type of male firefly sends out a certain signal when it wants to mate. A female firefly then mimics this signal. When the male comes over to her because he thinks that she wants to mate, she kills him and eats him. There are many more examples. For more, got to: http://www.britannica.com/bps/additionalcontent/18/22604917/DO-ANIMALS-LIE

By: Michael L.

Michael L. — Fri, 12 Mar 2010 00:14:15 +0000

Nice post Collin! When I read this post it reminded me of something similar that humans do. Some people will take steroids to enhance the size of their muscles to seem more intimidating to others and also to attract a mate. Fiddler crabs are able to regenerate their big claw after molting a few times. The reason they are bigger and lighter than the original is to be more successful for reproduction. If they seem like a good mate they will reproduce and pass on their genes. So through natural selection crabs with the “cheap” claw gene began to appear more in the species.

http://www.anu.edu.au/BoZo/backwell3/Fiddler%20Crabs.htm

By: bobby

bobby — Thu, 11 Mar 2010 16:35:26 +0000

this is really cool, i never wouldve though that animals could be this smart. i found that a horned lizard when its being attacked takes its horns and increases its sinus presssure so that its eyes pop out and squirt blood at its predator. here are a bunch of differnt defense mechanisms.
http://scienceray.com/biology/zoology/strange-defense-mechanism-of-animals/

By: Alec

Alec — Thu, 11 Mar 2010 15:17:38 +0000

Many animals have qualities that appear to be intimidating, however, most of these animals are bluffing. For example, bluffing occurs when two crayfish fight over a mate. The larger claw that a crayfish has is not it’s most important weapon. In fact, the other claw does more damage. However, there is an evolutionary advantage to possessing the big claw. If two crayfish are ready to fight, and if one frayfish as a significantly larger claw than the other, then the crayfish with the smaller claw will flea. The anglerfish is another animal that bluffs. On the tip of the anglerfish’s snout a rod that has a glowing end which acts as fish bait. The glowing tip looks like a worm, or even a clump of alge to nearby fish. The nearby fish think it is a tasty snack, when in fact the anglerfish jiggles the bait in front of it’s so lure the fish as close as possible. Then, right when the smaller fish takes a bite at it’s “snack”…SNAP, the anglerfish has dinner!

the information from the post was found on: http://www.livescience.com/animals/070726_crayfish_bluffing.html
http://findarticles.com/p/articles/mi_qa4128/is_200610/ai_n17194550/

By: Justin

Justin — Thu, 11 Mar 2010 00:45:42 +0000

I find it very interresting that fiddler crabs can easily regenerate limbs.Regeneration is the process off growing a limb after it is lost.No mammals are known to regenerate limbs but salamanders are one of the few organisms with this ability.Salmanders when approached by their prey make their tail fall off,this distracts the predator for long enough to allow the salamander to get away.
http://www.sandiegozoo.org/animalbytes/t-salamander.html

By: Michael L.

Michael L. — Wed, 10 Mar 2010 15:23:47 +0000

This is a great thing for evolvement in the crab because they say that it is a learned trait. Since the claw keeps growing and getting larger they have a better chance of producing offspring. Therefore, they have chances to always reproduce. I also found out something interesting, because the Vervet Monkey has this emergency call that it uses to distract its predator. Its main predators are Leopards and Eagles. Vervet Monkeys later have an amazing memory and then they know how to escape its predator. There have also been studies about how they do their call to bring nearby family and monkeys. They do this to be protected.

http://www.outtoafrica.nl/animals/engvervetmonkey.html?zenden=2&subsoort_id=1&bestemming_id=1

By: CHRISTIAN

CHRISTIAN — Wed, 10 Mar 2010 15:22:46 +0000

great post collin. fiddler crabs are really cool, their claws and ability to regenerate is awsome. i did some research on the regeneration process of a starfish, and found that, when a starfish loses an arm or leg the regeneration process is just a structure rebuilding every cell.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692227/
here is a video of starfish regeneration.
http://www.youtube.com/watch?v=f7cXeWxxfD4

By: Charlot

Charlot — Tue, 09 Mar 2010 22:45:21 +0000

I never knew that fiddler crabs could grow back claws after losing one. What really interests me is that every time they re-grow a claw, it gets bigger and bigger but has less physical use and is more for show. I was also interested in how Mike mentioned the idea of limb regrowth in humans.

I found an article about the possibility of humans regenerating limbs. The study shows that salamanders can regrow limbs, but most other animals and humans can’t. Scientists did an experiment on a chick that was still in its embryo. They took off a part of one of the wings and activated the Wnt signaling system. This is a system that plays a role in cancer cell spreading. The chick grew back its wing. This method could be useful in the future for human limb regrowth, but there are some serious consequences. If the Wnt signaling stays on for too long, it can cause cancer.

http://www.scienceagogo.com/news/20061019233435data_trunc_sys.shtml

By: Rohit

Rohit — Tue, 09 Mar 2010 15:01:04 +0000

This was a very interesting post. I never knew that fiddler crabs were dishonest. It’s also amazing how fiddler crabs produce another claw after losing it. The new claw looks similar but it is not the same. Dr. Lailvaux and scientists from Australian National University measured the size of the major claw in male fiddler crabs, and two elements of fighting. They found out that the size of an original claw accurately reflects its strength and the crab’s ability to avoid being pulled out of its burrow. This is not the same for a regenerated claw. This is the site I found the study on.

http://www.terradaily.com/reports/Fiddler_Crabs_Reveal_Honesty_Is_Not_Always_The_Best_Policy_999.html