Arthropoda (largest group of animal Kingdom)

Arthropoda

1. ARTHROPODA General characteristics and classification upto classes . Eco morphological Notes on : Limulus , Paleomon , Cancer, Scolopendra , Julus , Bombyx , Periplanata , Palamnaeus

2. General Characteristics Endocrine system Reproduction Development Arthros =Joint, podos =foot Largest and most successful phylum Comprises more than 80%of known animal species Body form Symmetry Germ layers Level of organization Head Appendages Body Wall Endoskeleton Body cavity Digestive tract Respiration Circulatory System Excretory System Nervous System

3. CLASSIFICATION Mandibulata Body: Head, Thorax, Abdomen Head appendages: 1 or 2 pair of antennae Compound eyes common Has seven Subphyla. Of these only Trilobitomorpha , Chelicerata and Mandibulata are definitely arthropods. Trilobitomorpha Fossil trilobites Cambrian to Permian period Body three lobed Head distinct, with one pair of antennae. Appendages Body Wall Chelicerata Body: Cephalothorax and Abdomen Cephalothorax: 6 pair appendages Ist pait : chelicerae with claws 2 nd pair: pedipalps 4 pairs: walking legs Antenne and true jaw absent

4. Classes of Chelicerata I. Merostomata Marine with median simple and lateral compound eyes 5 to 6 pairs of abdominal appendages Abdomen ending in a sharp telson or spine Excretion by Coxal gland . Example : Limulus

5. II. Arachnida (Scorpions, Spiders, ticks) Terrestrial or aquatic Eyes simple no compound eyes Cepahalothorax with two chelicerae, two pedipalps and 4 pairs of walking legs Abdomen without appendages Respiration through tracheae, book lungs or both Excretion by coxal glands and malphigian tubules Dioecious . Mostly oviparous courtship, before mating Example: Palamnaeous , Achaearanea , Sarcoptes

6. SCORPIONIDA 12 segmented 4 pairs of book lungs telson ARANEAE Chelicerae 2 jointed Opisthosoma with 3 pairs of spinnerets, no telson ACARINA Prosoma and opisthosoma indistinct Largest arachnid order

7. Classes of Mandibulata I. Crustacea Cephalothorax Exoskeleton chitinous and hard Head 5 segmented (2 pairs antennae, 1 pair mandibles, 2 pairs maxillae. Appendages usually biramous . Respiration by gills or body surface. Excretion by antennal glands Sexes separate, development has nauplius larva Example : Daphnia (Water flea) , Cyclops ( Copepods) , Argulus (Lice)

8. II. Myriapoda ( Chilopoda and Diplopoda ) Exclusively Terrestrial Body worm like, made of head and elongated trunk with many similar leg-bearing segments. Antennae 1 pair, jaws 3 pairs, legs more than 11 pairs. Respiration by tracheae. Spiracles arranges segmentally. Excretion by 1 or 2 pair of malphigian tubules Example: Julus , Scolopendra

9. II. Insect Body made of head (6 fused segments), Thorax (3 segments) and abdomen (up to 11 segments) Head with compound eyes (1 pair), antennae (1 pair), mandibles(1 pair) and Maxillae (2 pairs) Mouth parts modified for different feeding habits. Thorax with 3 pairs of joined legs and 1 or 2 pairs of wings which may be absent. Respiration by tracheae. Spiracles lateral. Excretion by malphigian tubules Unisexual. Fertilization internal. Development usually with metamorphosis. Example: Lepisma , Poecilocercus , Schistocercus , periplaneta , Gryllus , mantis, Ephemera, Termite, Forficula , pediculus , Cimex , Aphids, Beetles, Butterflies, Moths, Musca , Culex , Drosophila, Apis , Ants, Peripatus