Arthropods. “Jointed-legs”. Arthropods . Chitinous exoskeleton Paired of jointed appendages Growth accompanied by ecdysis or molting Open circulatory system Ventral nervous system Complete digestive tract Metamorphosis . Types of arthropods. Arachnids Crustaceans Chilopods
The female black widow is one of the most poisonous creatures with venom more potent than coral snakes, cobras or rattlesnakes. However her bite is rarely fatal in humans. Why not?
The sexes are separate. Eggs are attached to the swimmerets (swimming legs) of the female. The first pair is enlarged in the male (it is used to pass sperm to the female).