Uploaded byAnzaDar3
Lecture 9 (arthropoda)
Arthropods are segmented animals with jointed appendages, an exoskeleton, and a body divided into three parts. They include insects, spiders, crabs, and others. Arthropods have a complete digestive system, respiratory systems like gills or trachea, and open circulatory systems. They are found worldwide and are important as food, for agriculture, and unfortunately can transmit diseases. The phylum is divided into subphylums including Trilobitomorpha, Chelicerata, Myriapoda, Crustacea, and Hexapoda.
More Related Content
Similar to Lecture 9 (arthropoda)
Lecture 9 (arthropoda)
- 1.
- 2. General Characteristics • Segmented •Jointed appendages • Hard external skeleton • 3 parts-head, thorax, abdomen (arachnids exception) • Exoskeleton-hard, external skeleton made of chitin • Molting- shed old exoskeleton and secrete a larger one, very vulnerable after molting • Complete digestive tract ( mandible -chewing or proboscis - sucking) with a dorsal heart and a ventral nervous system
- 3. • Respiration throughgills, trachea, book lungs or body surface • Sensory organs include antennae and hairs, simple and compound eye • Reproduces (mostly sexually), one to several larval stage • The muscle system is more or less assisted by hydraulics originated from the blood pressure created by the heart • Respiration through gills, trachea, book lungs or body surface • With open circulatory system. Haemolymph that contains haemocyanin , a copper-based oxygen- carrying protein General Characteristics
- 4. Distribution and Abundance Arthropodsare found in almost all of the habitats that cover the Earth’s surface, even in your own room!
- 5. Importance • The largercrustaceans- shrimps, lobsters, and crabs- are used as food throughout the world. • Although many species of insects and mites attack food crops and timber, arthropods are of enormous benefit to human agriculture. • The stings and bites of arthropods may be irritating or painful, but very few inject dangerous toxins. • Medically, arthropods are more significant as carriers of diseases.
- 6. Arthropod relation tous.. Medical Arthropod: • Arthropods related with human health. Medical Arthropodology: • Morphology, taxonomy, life cycle, ecology, transmission of the diseases, control measures. Examples: • Flea Bubonic Plague • Soft tick Q fever • Mosquito Malaria
- 7.
- 8. Subphylum Trilobitomorpha General characters •Primitive arthropod • Extinct form • Abundant during Paleozoic era • Body is divided into three lobes, hence the name trilobitomorpha • Body division; head, abdomen and pygidium • Head bears a pair of antenna and eye • Eyes were compound • Appendages biramous • Structural differentiation of body parts absent Classes Trilobita (extinct)
- 9. Subphylum Chelicerata General characters •Presence of chelicerae (modified anterior most appendages) • Cephalothorax or prosoma with anterior six segments • Abdomen or opisthosoma with thirteen segments • Abdomen is divided into mesosoma and metasoma • Antennae completely absent Classes • Arachnida; spiders and scorpions • Merostomata; Horseshoe crabs • Pycnogonida; Sea spiders
- 10. General characteristics • Includemillipedes and centipedes • All are terrestrial arthropods • Usually contain many legs • Single pair of antenna • Eyes simple • Mouthparts lie on the underside of head • Upper lip of mouth with epistome and labrum • Lower lip with pair of maxillae • A pair of mandibles present • Breathe through spiracles that connect tracheal system similar to insects • Excretion through malpighian tubules Subphylum Myriapoda
- 11. Classes This subphylum includefour classes • Chilopoda; centipedes • Diplopoda; millipedes • Pauropoda; • Symphyla; Subphylum Myriapoda
- 12. Subphylum Crustacea General characteristics •Usually marine aquatic arthropods • Head and thorax fused to form cephalothorax • Cephalothorax usually covered by single large carapace • Eyes are compound • Two pairs of antenna, five pairs of cephalic appendages • Respiration through gills • Excretion by green glands or antennal glands • Paired gonopores • Development is usually indirect • Larval form is called nauplius
- 13. Classes This subphylum includesix classes a) Branchiopoda; Brine shrimps b) Remipedia; Bind crustaceans c) Cephalocarida; Horseshoe shrimps d) Maxillopoda; Barnacles e) Ostracoda; Seed shrimps f) Malacostraca; lobsters, crabs, shrimps Subphylum Crustacea a b c d e f
- 14. Subphylum Hexapoda General characteristics •A large taxa include insects and a group of wingless arthropods • Body plan; three parts, head, thorax and abdomen • Head with six segments • Thorax with three pairs of jointed legs (hence the name hexapoda) • Head contains a presegmental acron which bears compound eye • Head segments are closely fused • Antennae present • Mouth lie between the 4th and 5th segment of head • Thorax with three segments, each bears a pair of legs
- 15. General characteristics • Abdomenusually with 11 segments • Abdomen appendages are absent or extremely reduced • Abdomen contain most of the internal systems such as respiratory, excretory and reproductive system • Respiration through tracheal system • Excretion through malpighian tubules • Development always indirect • Larval stages present which undergo metamorphosis Subphylum Hexapoda
- 16. Classes Hexapoda is dividedinto two classes • Insecta; winged insects • Entognatha; wingless insects Subphylum Hexapoda