Arthropods Flashcards
What subphyla exist in the arthropoda?
How are they organised?
- Chelicerata (A)
- Myriapods (B)
- Crustacea (paraphyletic) (C)
- Hexapods (D)
- Trilobites (extinct) (E)
(E, A,(B,C,(A)))
(B,C,(A)) = Madibulata
Describe the generalised structure of arthropod?
- segmented
- joint appendages
- exoskeleton cuticle
- circulatory system
- ventral nerve cord
- musculature
- through gut
What are the different cuticles called that make up the arthropod skeleton?
Ventral side: Sternite
Dorsal side: Tergite
Appendage interface: Plurite
Describe the arthropod circulatory system.
Heart on dorsal side
Hemocele fills body cavity to help nutrient and gas exchange to all body parts
Why do most arthropods have heterogeneous segmentation?
Segments have been:
- lost
- fused
- specialised
What is tagmosis?
The grouping of segments with similar function /structure over evolutionary time
Tagmosis occurred independently between insects, crustacean and chelicerates
What distinct body areas have been made due to tagmosis?
- Head region
- thorax
- abdomen
OR
- Cephalothroax
(fused head and thorax)
What appendage muscles do arthropods have?
- Flexor allow appendage to be bent
- Extensor muscle allow appendage to be extended
- Protractor muscles appendage to be pulled away from body
- Retractor muscles appendage to be pulled towards body
What is ecdysis?
The process of moulting
Stages:
- Pre-moult
(new cuticle developes under dead-old cuticle)
- Moult
(shedding of old cuticle) - Post-moult
(new moult gets harder through sclarotization) - Inter-moult
(periods between moulting)
Describe the structure of Myriapods.
- head and trunk region
- single antennae
- open tracheae
(thus limited to humid environments)
Describe the general structure of Chaliserates.
- two tagmata
cephalothorax and abdomen - compound eyes
What are the many uses of silk to spiders?
- reproduction
(sperm web) - feeding
- sensing
- locomotion
- dispersal
(spiderlings produce silk from spinnerets and balloon around)
What are the six major classes of crustacea?
- Maxillopoda (polypheytic)
Tongue worm
Fish lice - Ostracoda
Sea shrimp - Branchiopoda
Fairy shrimp
Water fleas
- Malacostraca (and Maxillopoda) Crabs Krill Woodlice Barnicles (the rest of the maxillopods)
- Remipedia
- Cephalocarida
What is the general crustacea body plan?
- two paired antennae
- metamorphosis
(with nauplius larvae) - No general body plan
(but at least two tagmata)
What is the standard tagmosis of malacostraca?
- Head, thorax, abdomen
- Appendages on each
What is the general hexapod body plan?
- 3 tagmata
(head, thorax, abdomen) - tracheal system
(abdominal spiracles, waxy cuticles, hyperosmotic excreta)
What are the two main classes of hexapod?
- Enthognatha
- Insecta (Ectognatha)
What are the two Insecta subclasses?
- Apterygota (wingless)
- Pterygota (winged, 2 in adult)
What are the four major superorders of the pteragota
- Paleoptera
Mayflies
Dragonflies
Damselflies - Polyneoptera
Grasshopper
Termites
Mantises - Paraneoptera
True bugs
Lice - Holometabola
Major four
What is the mode of development in the holometabola?
holometabolous development
- Egg
- Larva
- Pupa
- Adult
What are the major four
Lepidoptera
Hymenoptera
Coleoptera
Diptera
What is hemimetablous development?
- Egg
- Nymph
- Adult
What are the different specialised appendages of insect?
Curosial foreleg
(walking)
Saltartory hind leg
(jumping)
Fossorial forelegs
(digging)
Natatorial hing leg
(swimming/diving)
Raptorial foreleg
(catching)
What are the different specialised mouth parts of insect?
Chewing
Lapping
Siphoning
Piercing
