Animal Portal : Information on animals
Animal Resources
  Endangered Animals New!
  Animal Information New!
  Animal List
  Baby Animals
  Desert Animals
  Rainforest Animals
  Extinct Animals
  Extinct Birds
  Extinct Mammals
  Animal Cells
  Animal Sounds
  Animal Names
  Animal Group's Name
  Animal Crossing
  Stuffed Animals
  Animal Shelters
Cats & Dogs
  Dog as a friend
  Cats
  Cat Care
Animal Issues
  Animal Testing
  Animal Behavior
  Animal Cruelty
  Animal Rights
  Animals In Danger
  Animal League
Animal Pictures and Wallpapers
  Animal Pictures
  Animal Wallpapers
  Cute Animal Pictures
  Stuffed Animal Pictures
Animal Port Partners and Links
  Animal Port Partners
  Sitemap

Arachnids


Arachnids General Anatomy

Arachnid, term for animals in the class including the scorpions, spiders, daddy longlegs, mites, and ticks, and certain other eight-legged land invertebrates. Fossils suggest that arachnids were among the first animals to live on land, perhaps in the early Devonian Period, nearly 400 million years ago. About 60,000 species are known, although many, especially mites, remain undiscovered or undescribed. Arachnids are found throughout the world in nearly every habitat, but they reach their greatest size and diversity in warm arid and tropical regions.

Characteristics


The arachnid body is divided into two parts: anterior and posterior. The anterior part, called the cephalothorax, contains sense organs, mouthparts, and limbs in pairs. The first pair of limbs-the chelicerae-may form pincers or poison fangs, and the second pair-the pedipalps-may serve as pincers, feelers, or legs. The other limb pairs, generally four, are used for walking. The posterior part of the body, the abdomen, bears the genital opening and other structures. It is usually equipped with modified gills called book lungs. Most arachnids are solitary except at the time of mating, when a variety of complex behavior patterns may be observed. Females may guard eggs or young, which are often born live.

Behavior and Importance


Arachnids are usually predaceous. Often they hunt or lie in wait for small animals such as insects. Food may be partly or wholly broken down by secreted fluids and then sucked in. Arachnids have simple eyes and various prey-subduing structures, such as the segmented, stinging tail of scorpions and the abdominal spinnerets with which spiders construct elaborate insect traps (orbs or webs). Mites constitute the largest and most diverse order of arachnids, followed by the spiders. Some mites feed on plants and a few species are serious agricultural pests. Some are predaceous, often feeding on other species of mites. Parasitic lifestyles are common among mites and many are of veterinary and medical importance. Ticks are a distinct bloodsucking subgroup of mites specialized for parasitizing reptiles, birds, and mammals. Ticks carry organisms that cause serious human diseases, such as Lyme Disease. The bites of some spiders and the stings of a few species of scorpions are dangerously poisonous to humans (see Black Widow Spider, Brown Recluse Spider). However, most arachnids are harmless and contribute to the balance of nature by controlling the populations of the insects they prey on or the plants, reptiles, birds, or mammals that serve as their hosts.

Scientific classification


Arachnids constitute the class Arachnida, in the phylum Arthropoda. The class is divided into 11 orders: the Acari or Acarina (mites and ticks), Amblypygi (tailless whipscorpions), Araneae (spiders), Opiliones (daddy longlegs), Palpigradi (palpigrades), Pseudoscorpiones (false scorpions), Ricinulei (ricinuleids), Schizomida (micro whipscorpions), Scorpionida (true scorpions), Solpugida (windscorpions), and Uropygi (whipscorpions).

List Of Animals
Aardvarks
African Clawed Frog
African Elephants
African Grey Parrots
African Wild Dog
Africanized Bees
Albatross
Amazon River Dolphin
Anacondas
Anadromous Fish
Anadromous Fishes Chinook Salmon
Anadromous Fishes Coho Salmon
Anadromous Fishes Steelhead
Andean Condors
Anemone Crab
Anemone Shrimp
Angel Shark
Angelfish Breeding
Angelfish
Annelids Earthworms
Annelids Leeches
Annelids
Antelopes
Antlions
Ants
Apes
Arachnids
Arctic Terns
Armadillos
Arowana
Arrow Crab
Arthropods
Asian Barbets
Asian Elephants
Asiatic Black Bear
Atlantic White Sided Dolphins
Australian Brush Turkey
Australian Fur Seal
Avocets
Axolotls
Babirusa
Baboons
Badgers
Bald Eagles
Baleen Whales
Ball Pythons
Banded Coral Shrimp
Bandicoots
Barn Owls
Basilisks
Basking Shark
Bass
Bats
Bearded Dragons
Bears
Beavers
Bed Bugs
Beluga Whales
Bengal Tigers
Betta Splendens
Betta Splendens
Bilbies
Bird Eating Spiders
Bird Eating Spiders
Black Howler Monkeys
Black Bear
Black Dogfish Shark
Black Howler Monkeys
Black backed Three toed Woodpecker
Blood Red Fire Shrimp
Blue Crabs
Blue Shark
Blue Whale
Bluebirds
Boa Constrictor
Boa Constrictor
Bobcats
Bogong Moth
Bongo
Bonobos
Boobies
Bottlenose Dolphins
Bottlenose Whales
Bowhead Whales
Brine Shrimp
Brine Shrimp
Broad Winged Hawks
Broad Winged Hawks
Brown Pelican
Brown Bear
Brown Pelican
Brydes Whales
Buffalo
Bull Shark
Bull Shark
Burrowing Owls
Burrowing Owls
Button Quail
Button Quail
Caenorhabditis elegans
California Condors
California Quail
California Red Legged Frog
California Sea Lion
California Condors
California Quail
California Red Legged Frog
California Sea Lion
Camel Spiders
Camel Spiders
Camels
Canada Goose
Canada Goose
Canaries
Cane Toad
Cane Toad
Capuchin Monkeys
Capuchin Monkeys
Capybaras
Caribou
Carpenter Bees
Carpenter Bees
Cassowary
Catfish
Centipedes
Cephalopods
Chatham Island Taiko
Cheetahs
Chickens
Chiggers
Chimpanzees
Chinchillas
Chinese Mitten Crab
Chipmunks
Cicadas
Cichlid
Clownfish
Cnidarians
Cobras
Cockatiels
Cockroaches
Coelacanth
Common Dolphin
Common Loons
Cookie Cutter Shark
Coopers Hawks
Copepods
Copperheads
Cougars
Cow
Cowbirds
Coyotes
Crab
Crane Fly
Crane
Crayfish
Crickets and Grasshoppers
Crocodiles and Alligators
Crustaceans
Cuscus
Daddy Long Legs Spiders
Dama Gazelle
Deer
Degu
Desert Pupfish
Desert Tortoise
Devils Hole Pupfish
Dik Diks
Dingoes
Discus
Dodo
Donkey
Downy Woodpecker
Dusky Shark
Eagles
Earthworms
Eastern Cougar
Eastern Mole
Echidna
Egrets
Finback Whales
Giant Panda
Golden Eagles
Great White Shark
Hairy Woodpecker
Harlequin Shrimp
Harpy Eagles
Humpback Whales
Minke Whale
North Atlantic Right Whale
Northern Flicker
Northern Three toed Woodpecker
Oceanic Whitetip Shark
Orca Killer Whale
Palm Cockatoos
Pileated Woodpecker
Polar Bear
Porbeagle Shark
Portuguese Shark
Purple Shore Crab
Red Bellied Woodpecker
Red headed Woodpecker
Rough Sagre Shark
Sand Tiger Shark
Scarlet Skunk Cleaner Shrimp
Sei Whale
Sharks
Sharpnose Shark
Shortfin Mako Shark
Slipper Lobster
Sloth Bear
Smooth Dogfish Shark
Smooth Hammerhead Shark
Spectacled Bear
Spiny Dogfish Shark
Spiny Lobster
Starfish
Sun Bear
Thresher Shark
Tiger Shark
Wallabies
Walruses
Wasps
Water Dragons
Waterbucks
Weasels
Western Yellow billed Cuckoo
Whale Shark
Whales
White Beaked Dolphins
White Pelican
Whitetip Reef Shark
Whooping Cranes
Widow Spiders
Wild Canids
Wild Cats
Wild and Feral Horses
Wildebeest
Wildlife
Wobbegong Shark
Wolf Spiders
Wolverines
Wolves
Wombats
Wood Storks
Woodpeckers
Worms
Yaks
Yellow Bellied Marmot
Yellow bellied Sapsucker
Zebra Finches
Zebrafish
Zebras
camels adaptations
camels australia
camels biology
camels information
camels life
camels people
camels uses
lis
template



© 2003-2004 - animal information - All Rights Reserved