Phylum Arthropoda

Jointed Legs

Number of species Mollusca Chordata Platyhelminthes Nematoda Arthropoda Porifera Annelida Echinodermata Sarcomastigophora Apicomplex Ciliophora

Characteristics of Arthopods Segmented, bilateral body Jointed appendages Exoskeleton Open circulatory system Ventral nerve cord Compound eyes

Arthropods Most Successful Animals Number of species Diversity Distribution Longevity

Reasons for Success Versatile exoskeleton Segmentation Oxygen piped directly to cells (terrestrial) Highly developed sensory organs Complex behavior Metamorphosis

Fig. 19.10

Modifications of Exoskeleton Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Modifications of Exoskeleton From A Life of Invertebrates, Copyright © 1979, W. D. Russell-Hunter.

Compound Eye

Metamorphosis

Monarch Butterfly

Echinodermata Uniramia Chelicerata Vertebrata Crustacea Other Chordata Lophophores Crustacea Other Chordata Arthropoda Annelida Hemichordata Mollusca Other pseudocoelomates Nemertea Platyhelminthes Nematoda Ctenophora Cnidaria Mesozoa Placozoa Sarcomastigophora Ciliophora Porifera Apicomplexa Microspora Myxozoa

Arthropod Groups Subphylum Trilobita Subphylum Crustacea Subphylum Chelicerata Subphylum Uniramia

Subphylum Trilobita Extinct One pair of antennae Biramous appendages 200 MYA One pair of antennae Biramous appendages

Subphylum Chelicerata Chelicerae No antenna No mandibles 4 pair of walking legs 1 pair of pedipalps

Class Merostomata Limulus Carapace Telson Dates back to Triassic 245 MYA Carapace Telson

Fig. 18.2a

Fig. 18.2b

Class Arachnida Spiders Scorpions Ticks Mites

Class Arachnida 4 pair of legs 2 body segments Most are predators Except mites & ticks Most are predators Inject enzymes into prey Suck fluid into pharynx

Arachnid Body Regions Prosoma or Cephalothorax Ophisthosoma or Abdomen

Order Scorpionida Large pedipalps Abdominal stinger Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Order Scorpionida Large pedipalps Abdominal stinger Photo (a) © SS#11/PhotoDisc

Order Araneae Spiders Fangs with poison glands Silk glands

Fig. 18.4

Fig. 18.5

Copyright © The McGraw-Hill Companies, Inc Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Arachnid Book Lung

Dugesiella Tarantula

Latrodectus mactans Black widow spider Neurotoxin

Loxosceles reclusa Fiddle back spider Necrotoxin Brown recluse Brown Violin Necrotoxin

Loxosceles reclusa Necrosis of tissue

Day 3

Day 4

Day 5

Day 6

Day 9

Day 10

Order Acari Ticks Mites Body segments fused

Rocky Mountain Spotted Fever Ticks are vector High fever Headache Muscle pain Rash BEGINS ON EXTREMETIES 25% fatal without antibiotics

Dermacentor variabilis Dog tick Dermacentor andersoni Wood tick

Fig. 18.16

Dermatophagoides Dust mite Allergies to fecal products 1 gram of dust holds 250,000 droppings

Trombicula Chigger mite Larva feed on skin Dermatitis

Subphylum Crustacea

Subphylum Crustacea Two pair of antennae Biramous appendages

Fig. 19.3

Fig. 19.1

Crayfish

Fig. 19.2a

Fig. 19.2b

Fig. 19.5 Fig. 19.5

Fig. 19.6

Fig. 19.7 Fig. 19.7

Lobster

Shrimp

Crab

Pill Bug

Fig. 19.15c

Fig. 19.16c

Copepod

Barnacles

Barnacle Cirri Testis Penis Anus Mouth Stomach Ovary Cement gland

Fig. 19.24a Fig. 19.24a

Subphylum Uniramia One pair of antennae Uniramous appendages

Class Chilopoda One pair of legs per body segment Poison fang Flattened bodies Carnivores

Class Diplopoda Two pair of appendages per body segment Cylindrical body Herbivores

The End