动物生物学-节肢动物.pptxVIP

Arthropods 节肢动物General Characteristics? Heteronomous metamerismArticulatory appendages (most can fly) Mixocoel, open circulatory system? Chitinous exoskeleton? Highly adaptive? Highest diversityHeteronomous metamerism / tagatization异律分节Specialization of body regions for specific functionsThe development of groups of body segments fused into functionally distinct body regions? Head: feeding, sensing? Thorax: locomotion? Abdomen: reproductionIn the primitive forms?? Body is composed of a series of similar segments, each bearing a pair of appendages? No septa divide the body cavity? Organ systems are not metamerically arranged? head + thorax + pygidium 尾板thrilobite 三叶虫? head + trunksubphylum Myriapods 多足类? cephalothorax 头胸部 + abdomensubphylum Chelicerata 螯肢类 , subphylum Crustacea 甲壳类? head (6 segments）+ thorax (3 segments）+ abdomen (11 segments)subphylum Hexapoda 昆虫类（六足亚门）cephalothorax 头胸部 + abdomensubphylum Chelicerata 螯肢类 , subphylum Crustacea 甲壳类head (6 segments）+ thorax (3 segments）+ abdomen (11 segments) subphylum Hexapoda 昆虫类Articulatory appendages 分节的附肢Each appendage is divided into several segments, which are connected with jointsAppendages specialized in morphology and function? Antenna? Mouthparts? Structures aiding respiration and reproductionEvolutionary advantagesImprovement of flexibility in movement?? contributing to their successparapodia and setae 鼓膜触须气门Chitinous exoskeleton 几丁质的外骨骼几丁质：N-乙酰D-氨基葡萄糖聚合物? Location - all body surfaces and invaginations内陷 of the body wall? Origin - secreted by single-layered epidermal cells? Structure - two layersWater conservation?? a major concern for any terrestrial organism1. Outer layer ? epicuticle 上角皮: made of a waxy lipoprotein 脂蛋白?? impermeable不渗透的 to water?? hard due to sclerotization 硬化Sclerotization: a process in which layers of protein are chemically linked with one another2. Inner layer ? procuticle 原角皮 : made of chitinchitin = polysaccharide + proteins?? no sclerotization and deposition of calcium carbonateFu