Four sub-phylum of Arthropods

PHYLUM ARTHROPODATRILOBITES CHELICERATES

CRUSTACEANS

UNIRAMIANS

UNIRAMIANS• Insects (the most species)

– Grasshoppers– Butterflies– Bees– Moths– Beetles– Ants– Termites

• Centipedes• Millipedes

Uniramians- Insects• 3 part body (head, thorax, abdomen)• 3 pairs (6 total) of legs• 1 pair of antennae, 2 pairs of wings, compound eyes• Mouthparts are often adapted to the food source

e.g. grasshoppers cut and chew plant tissue(Female) mosquito sharp tube to pierce skin and suck bloodButterfly retractable “straw” for sucking nectarFly spongy mouth part to soak up foodBee chew pollen

• Many are social insects:– Form colonies of

individuals doing different jobs (division of labour)

– “Caste” (levels)– Each member of the

castes develop a body specialized for their jobs

• Use pheromones (chemical messengers) to communicate

Uniramians- Insects

ANTS!

• Read• Clip:

..\..\..\Lesson Videos\Biology 11\Arthropods and Echinoderms\Leafcutter Ants - the First Agriculture.flv

• Please do a species file on the “leaf cutter ant” from video above

• Movie: http://www.youtube.com/watch?v=wKbj3ZDmvdU

Crustaceans

• Nearly all are suspension filter-feeders• Larger species predator/scavengers• Appendages specialized for cutting, tearing,

collecting• Respiration• All Crustaceans have gills• median simple eye or compound eyes • Sensory hairs for mechano- and chemoreception

• The class includes a wide variety of familiar animals, such as barnacles, crabs, crayfish, copepods, shrimp, prawns, lobsters, water fleas, and wood lice.

• More than 30,000 species of crustacea have been identified, the majority of which live in water.

• Species that live in moist habitats on land, such as wood lice and pill bugs, are believed to have evolved from marine species.

Species File (Gooseneck barnacle)

• Gooseneck Barnacle Pollicipes polymerus• So called because of its resemblance to a

goose neck and head• Barnacles anchor themselves to rocks by a

tough, flexible stalk (peduncle), which also contains the ovaries

• GEOGRAPHIC RANGEThe gooseneck barnacle is found from the southern region of Alaska to Baja, California.

PHYSICAL CHARACTERISTICS

• The gooseneck barnacle can be distinguished by its long neck, or stalk. This part of its body is usually one inch long. The stalk has a leathery appearance with a texture of small bumps.

FOOD HABITS

• The gooseneck barnacle is a filter feeder.• Since its head is attached to a usually rocky surface, it feeds

by extending its legs, or cirri, from its "shell.• Food is caught in a lassoing action of the cirri. Six pairs of cirri

contract and force the food down towards the mouth. • Since food may be hard to come by at low tide, the

gooseneck barnacle can use some of its cirri to pass food to its mouth while using others to catch and hold onto new prey when food is abundant

REPRODUCTION• The gooseneck barnacle is a hermaphrodite• Although it is hermaphroditic, it usually will not self-

fertilize unless there are no other barnacles within about eight inches

• Once a female lays eggs, a pheromone is released letting those surrounding males know that she is ready. One barnacle will release sperm into the shell

• Thousands of free-swimming larvae are then released into the ocean

• These larvae are weak swimmers that spend their time feeding mostly on phytoplankton.

Reading

• Gooseneck barnacle

• Video: ..\..\..\Lesson Videos\Biology 11\Arthropods and Echinoderms\Project Kaisei - Jim Leichter Finds Barnacle Fouling Community - The Garbage Patch - Scripps.mp4