Animal Diversity Lecture 5

Moulting of the cuticle layer

Ecdysis

Round worms

Nematoda

aquatic habitats, soil, and within the tissues of plants and other animals, parasitic or free-living

Nematoda

Unsegmented Worms

Nematoda

Model organism for development, aging, regeneration

C. Elegans

Trichinellosis

Trichinella

Heart Worm

Dirofilaria

Arthropoda Characteristics

coelomates, exoskeleton, segmented bodies, jointed appendages

Occur in almost all habitats on earth

arthropoda

Arthropoda Classification

Trilobita, Cheliceriformes, Myriapoda, Crustacea, Hexapoda

Trilobites

Trilobita

Spiders, mites, and scorpions

Cheliceriformes

Millipedes and Centipedes

Myriapoda

Lobsters, crabs, barnacles, crayfish, shrimp, amphipods, isopods

Crustacea

Insects

Hexapoda

Extinct by Permian-Triassic boundary, all marine

Trilobita

All terrestrial, "extinct by the end of Permian

Cheliceriformes

Spiders have a _______ and a _________

Abdomen, Cephalothorax

Single pair of legs per segment

Centipede

Multiple pairs of legs per segment

Millipede

Carnivorous

Centipedes

Herbivorous

Millipedes

nearly 1 million described species, actual diversity may be between 2 million to 50 million

Hexapoda

In arthropods each stage called an instar

Ecdysis

Arthropod beneficial Function?

pollinators

Trouble with some arthropods?

plant destruction, invasive species, vectors,