Sunday, March 29, 2009

Coconut Crab

For Biology Class
The Coconut Crab
Phylum:
Crustacea
Class:
Malacostraca
Order:
Decapoda
Family:
Anomuridae
Genus
Birgus

Spesies:
latro

Wanted For:

Coconut Crabs will eat almost anything organic. In their ecosystem they act as scavengers eating dead animals, however, they also occasionally eat unwary prey, including other crabs, or rarely a rat. Also, as their name implies, they eat coconuts. Incredibly enough, they will climb up a coconut tree, cut a coconut from the tree, and return to earth to eat. Using their massive front claws, they rip away at the husk, and eventually crack it open. They also eat other fruit such as figs, in return spreading the fig seeds through fickle matter.
When in their Laval stage, still in the ocean, they also provide a food source to many species of fish. The adult crab has virtually no predators.

Last Known Whereabouts:They live among the islands of the Indian and Pacific Oceans mostly around Asia between the Tropic of Cancer and Tropic of Capricorn. As adults they must live on land and require fruit trees for their diet. They are largely nocturnal thrive in moist climates. The crabs need water to survive but will drown if submerged in water, so they make burrows in moist soil, and use their large claws and other gathered material to seal the entrance and keep moisture in. During the young larval stages, the crabs live in the tropical waters around the islands.

Considered Armed and Dangerous
:
The crab has several defensive tools and skills. It rarely uses its "weapons" for hunting. On the crabs back it has a carapace for protection. The crab also Has two large claws on its front side which are normally used for feeding and cracking open tough coconuts, but can be used for defense.

Description: The Coconut Crab is a decapod (10 legs) and its body consists of a thorax, abdomen and head, six powerful walking legs, two powerful claws (one of which is larger) , and a very small pair of claws near the rear which are used to brush water over the respiratory organs. the respiratory organs consist of gills, and spongy tissue laced with blood vessels that cover the gills and act as lungs. Another awesome feature of the crab is a sense of smell. The nose organ on the Coconut Crab is an cool example of convergent evolution, due to the fact the organs are exceptionally similar to the sensilia of other terrestrial insects, tho the crab originated from water crabs separately from other insects. The ability to smell greatly helps the crab to find carcasses and other food. The Color of the Crab varies greatly, and can be dark purple to bright yellow.

Last Seen Traveling: The Coconut Crab has 10 legs total, but only really uses 6 for walking. It typically walks sideways, but will sometimes move backwards to face a predator with its claws. It also has the ability to climb trees.

AKA: Other names are "Robber Crab" and "Palm Thief" due to its funny tendency to steal shinny objects.

Known Associates: During the juvenile stage, the crabs will typically make a home out of an old snail shell, and occasionally a coconut or other object. Other then this they are relatively independent. Mating occurs often between May and September. The male fights with the female pushing the her on her back and places a sperm sack on her9(using the tiny rear laws). She caries it for a few months during which she creates and fertilizes eggs, which she caries on her abdomen. she then releases the zoea into the water. The females sometimes do this in huge groups along the coast during the night.

Human Impact: The Crab is an endangered species due to human activity. Roads are often built through habitats and migration routs used during mating season. Cars often kill these crabs. Deforestation also affects them as they rely on trees for food and shelter. They are also apparently quite tasty and are eaten. However, being scavengers, the crabs do enjoy our trash and any leftover food, and often live near humans acting like giant clawed rats.

Brought To Life!!! Here is a video I created of a pretty accurate Coconut Crab brought to life via Spore(TM). About 20-30 seconds in, reality slips a little.


Work Cited:
pictures:

1:
http://www.flickr.com/photos/salpet/1118870692/
2: http://www.finerareprints.com/animals/histoire_naturelle/9151.jpg
3: http://biodiv.sinica.edu.tw/~coconutcrab/web/a_intro.html
4: http://www.teamteabag.com/wp-content/uploads/2008/02/coconut_crab.jpg

Scouces: - http://cookislands.bishopmuseum.org/species.asp?id=7038
- http://biodiv.sinica.edu.tw/~coconutcrab/web/a_intro.html
- http://web.ebscohost.com/ehost/detail?vid=1&hid=116&sid=c8c79615-c80a-4bbd-9c63-3d1f4c323300%40sessionmgr104&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=ani&AN=9500100792