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