Arthropods Flashcards
What makes Arthropods so successful?
1) Adaptable body plan
2) Thrive in a range of environments
3) Segmented body - “blocks”
4) Segments are fused allowing greater control
5) Exoskeleton with joint appendages
Tagmatisation/tagmosis
Fusion of segments producing “super-segments”
Arthropod Features (9)
1) Exoskeleton
2) Segmentation
3) Tagmata
4) Appendages
5) Respiratory structures
6) Circulatory system
7) Ventral nervous system
8) Complex excretory system
9) Sexual reproduction
what type of respiratory system do arthropods have?
Haemocoel system
Means they have an open system
Ecdysis
Moulting, allows for growth
Temporary vulnerability
Energetically expensive
Exoskeleton of arthropods are made of what? (2)
1) Protein
2) Chitin
What are the 5 lineages of Arthropods (both extinct and living): [5]
1) Trilobites - extinct
2) Chelicerates
3) Hexapods - (insects/6-legged relatives)
4) Crustaceans
5) Myriapod
What are the two categories of mouthparts
1) Chelicerate
2) Mandibulate
Chelicerae
Group of mouthparts
Chelicerate mouthparts are for grasping
Mandibules
Group of mouthparts
Mandibles are for chewing
What are the two groups are chelicerae and what are their functions
1) Chelicerae: Paired feeding structures modified into fangs (spiders) or pincers
2) Pedipalps: [palps] Feeding or sensory
Chelicerates
Group of organisms including
1) Spiders
2) Scorpions
3) Ticks
4) Mites
*4 Pair of legs, 8 legs total
How many legs to chelicerates have?
4 pairs of legs, 8 legs total
Two types of ticks with veterinary importance (2)
1) Babesia –> Tick fever
2) Ixodes holocyclus –> neurotoxin -> Tick paralysis
3) Boophilus –> Cattle tick
What are three ways ticks impact host
1) Anaemia –> Blood loss
2) Secrete toxins
3) Transmit pathogens
Boophilus life cycle
Cattle tick
1) Adult ticks on cattle
2) Engorged female lays 3000 eggs, and dies
3) Larval development: 2 months in summer; 7 months in winter; leads to “spring rise”
4) Larva quests
5) Attaches to host, feeds, moults
Why is it so difficult to remove a tick?
They have a hypostome
Hypostome
Toothed hypostomes are parts of the tick attachment mechanism which have backwards projecting teet
Pulling out can cause an anaphalactic reaction
Mites General Features
Ectoparasite
Transmission: Predominantly by contact
Ex) Scabies
Scabies
Ectoparasite Transmission by contact Cause mange Associated with severe dermatitis Characterized by hairloss, scabs, keratenized skin with mites
How many legs do Mandibulates have?
3 pairs of legs, 6 legs in total
Mandibulates general features
3 pairs of legs, 6 legs total
2 pairs of wings
Beetles are most abundant
Complex bodies - 3 tagmata (head-thorax-abdomen)
Features of Insecta
Hexapods - 6 legs
1) Exoskeleton
2) Excretory system
3) Advanced respiratory system
4) Advanced nervous system
5) Advanced sensory system
6) Internal fertilization
7) Resistant eggs
Apterygotes
Primitively wingless insects
Mostly simple mouths
