Invertebrates 4 Phylum Arthropoda Phylum Arthropoda jointed foot
Invertebrates 4 Phylum Arthropoda
Phylum Arthropoda: “jointed foot”
Basic Arthropod Features (cont. ) § Paired, jointed appendages § § joints allow for flexibility Segmentation § § In some, have similar segments throughout body In most: Segments combined into specialized body regions § § § Crustaceans have 2 regions: cephalothorax, abodomen Insects have 3 regions: head, thorax and abdomen Exoskeleton § Same materials also in mouthparts, wings, eye lens
Focus on Molting § § Function: growth New exoskeleton built under old § § § stretching by water or air in the digestive system and hemocoel vulnerable to predators while hardening mating can coincide with soft shell in female crabs Some arthropods grow all life Hormonal control
Subphylum Crustacea § Examples: Lobsters, crabs, shrimp, barnacles, copepods, etc. .
Subphylum Unirama § Insects, centipedes, millipedes
Subphylum Chelicerata § Spiders, mites, scorpions, horseshoe crabs
Various aspects of anatomy, physiology and behavior § Feeding § § Class Crustacea Class Insecta Subphylum Chelicerata Circulation/gas exchange § § Open circulatory system Respiration varies amongst subphyla and classes § § Class Crustacea: gills Class Insecta: tracheal system. CARRIES OXYGEN AND CO 2 Subphylum Chelicerata: tracheal system, book gills and book lungs Water/ion balance and ammonia excretion § § Crustacea: gills and green glands Insecta and Chelicerata: Malpighian tubules
Various aspects of anatomy, physiology and behavior § Nervous system § Cerebral ganglia § Ventral nerve cord (paired, fused) § Ganglia in each segment , or one ganglion for several segments § Reproductive systems § Usually internal fertilization § Spermatophores § Sperm storage
Review: Features
- Slides: 10