Тип Arthropoda Подтип Chelicerata Terrestrial almost

Тип Arthropoda

Подтип Chelicerata • Terrestrial (almost all) • Cephalothorax (8 segments) and abdomen (up to 12 segment and telson) • First 2 pairs of appendages - chelicers and pedipalps. • Excretory system – coxal glands (water animals); Malphigian tubes (terrestrial) • Digestive system – have a pair of outgrowth – “liver” • Respiratory system – gills on abdominal legs/ tracheae and lung • Development without larval stages

Spider’s chelicers and pedipalps

Класс Xipnosura • Marine, up to 90 cm • Abdomen ends with a long spike • Cephalothorax without antennae, covered with carapace, has 7 pairs of appendages, which have a small claw

Class Arachnida

Оrder Scorpiones • • • Ancient terrestrial order of Chelicerata Big pedialps with claws Abdomen has 12 segments, flexible metasoma Poison gland Lung

О. Pseudoscorpiones • Small arachnids (2 -3 mm), wide abdomen (11 segments), breath with tracheae, prey on small invertebrates

Оrder Aranei • Widely distributed, 0, 8 мм - 11 см • Web glands • Lungs and tracheae

Оrder Acariformes • • Small (0, 2 -0, 3 мм) Joint body (cephalothorax fused with abdomen) Breath through their skin or tracheae Metamorphosis

Оrder Parasitiformes • Feed on vertebrate blood, pierce host’s skin with chelicers. Inflate while feeding – abdomen grows multiple times. Transmit Rickettsia, Lime’s disease, encephalitis