Arthropoda Flashcards
What symmetry is Arthropoda?
Bilateral
Are Arthropoda segmented?
Yes - often somites (parts) fused together = tagmata
Explain the exoskeleton on Arthropoda. What has to happen to it?
Cuticle secreted by epidermis
Molted at intervals = ecdysis
Explain the coelom of Arthropoda
It’s reduced with most of body cavity consisting of hemocoel = filled with blood
What are the 2 different excretory glands in Arthropoda?
1- homologous to nephridia of Annelids
2- malpigian tubules
What do many Arthropoda undergo? 2 types
Metamorphism - complete or incomplete
What is the cuticle of Arthropoda made out of? (3)
Complex protein, chitin and lipids
How is the cuticles secreted in Arthropoda?
By single layer of epidermis cells
How is the cuticle strengthen in Arthropoda? (2)
1- calcification in crustaceans
2- sclerotization in insects
The chitin that makes up the cuticle in Arthropoda insolvable to what? (5)
Water, alcohol, diluted acids, alkalis, nor attached by digestive enzymes of mammals
What can breakdown the chitin in the cuticle of Arthropoda? (3)
Snails, some insects (cockroaches) and some bacterias
What are the 4 subphylums of Arthropoda?
1- Trilobitomorpha
2- Chelicerata
3- Uniramia
4- Crustacea
What is the 1 class under the subphylum Trilobitomorpha? What does this include?
Trilobita includes trilobites
Why are they called trilobites in the class Trilobita?
Body segmented into 3 parts = axial and lateral regions
How are the class Trilobita similar to ancestral Arthropoda?
Have paired jointed limbs
What time range did the class Trilobita exsist?
Fossils range from early Cambrian (600 MYA) to being extinct by Permian (275 MYA)
What does the subphylum Chelicerata lack?
No antennae
Explain the body of the subphylum Chelicerata
No distinct head - body with 2 tagmata
1- Prosoma (cephalothorax or anterior)
2- Opisthosoma (posterior)
What are the 1st pair of appendages on the subphylum Chelicerata? Called?
On prosoma and abated for feeding = chelicerae
What does the opisthosoma have in the subphylum Chelicerata?
Up to 12 segments and a postanal telson (Appendage attached to last segment)
What does the subphylum Chelicerata lack?
No antennae
Explain the body of the subphylum Chelicerata
No distinct head - body with 2 tagmata
1- Prosoma (cephalothorax or anterior)
2- Opisthosoma (posterior)
What are the 1st pair of appendages on the subphylum Chelicerata? Called?
On prosoma and abated for feeding = chelicerae
What does the opisthosoma have in the subphylum Chelicerata?
Up to 12 segments and a postanal telson (Appendage attached to last segment)
What are the 3 classes for the subphylum Chelicerata?
1- Merostomata
2- Archnida
3- Pycnogonida
What is the only example in the class Merostomata of the subphylum Chelicerata?
Horseshoe crabs
How does the class Merostomata (horseshoe crabs) differ from the rest of the subphylum Chelicerata?
Where other Chelicerata appendages are reduced or absent - horseshoe crabs have large plate like limbs and book gills used for locomotion and gas exchange
So what happens to other the Chelicerata appendages if they re reduces or lost unlike horseshoe crabs?
Become other Chelicerata limbs = special structures like spinnerets in spiders
What are the 4 examples of the class Arachnida of the subphylum Chelicerata?
Spiders, mites, ticks and scorpions
Explain the prosoma of the class Arachnida of the subphylum Chelicerata
(Cephalothorax) covered by carapace-like shield (hard shell)
Explain the opisthosomal of the class Arachnida of the subphylum Chelicerata. 2 examples
Appendages have been modified or absent
Spinnerets (spiders)
Pectines (scorpions)
What are the 2 things involved in gas exchanged for the class Arachnida of the subphylum Chelicerata?
Tracheae and book lungs
How does the class Arachnida of the subphylum Chelicerata feed?
Mites = parasitic Rest = predators - food partially digested externally then suck up by action of pumping stomach
What is the only example of the class Pycnogonida of the subphylum Chelicerata?
Sea spiders
What are the 3 things that the class Pycnogonida have in common with the rest of the subphylum Chelicerata?
1- claws on 1st appendages
2- tubercles with simple eyes
3- lack antennae
What are the 3 classes of the subphylum Uniramia?
1- Chilopoda
2- Diplopoda
3- Insecta
What are the examples of the classes Chilopoda and Diplopoda of the subphylum Uniramia?
Chilopoda = centipedes Diplopoda = millipedes
What are the 2 subclasses of the class Insecta of the subphylum Uniramia? How are they divided up?
1- Apterygota = wingless insects
2- Pterygota = winged insects
What are the 2 orders of the subclass Apterygota of the class Insecta? Examples
1- Collembola - springtails
2- Thysanura - bristletails
Explain bristletails of the order Thysanura of the subclass Apterygota (3)
Small, flattened and covered with scales
For the subclass Pterygota of the class Insecta, what are the 2 super orders and how are they divided up?
1- Hemimetabola - incomplete metamorphism or exopterygota
2- Holometabola - complete metamorphism or endopterygota
What are the 2 growth stages that both super orders of the subclass Pterygota go through?
1- growth and molting
2- metamorphosis
Explain molting (4 things it includes)
Shedding of the outer surface of the body, lining of tracheae, lining of anterior and posterior parts of the guts
Explain simple or incomplete or exopterygota metamorphosis (4)
Wings develop externally
Compound eye present
No resting stage for adults
Young called nymphs = similar but smaller to adults
Explain complete or endopterygota metamorphosis (stages + 4)
Egg -> larva -> pupa -> adult Larva is grub like Some have legs and others don't No compound eyes Wings start to develop internally
What are the 4 orders of the super order Hemimetabola of the subclass Pterygota of the class Inescta of the subphylum Uniramia? Give an example for each.
1- Odonata - dragonflies
2- Ephemeroptera - mayflies
3- Orthoptera - grasshoppers
4- Blateria - cockroaches
What are the 4 orders of the super order Holometabola of the subclass Pterygota of the class Inescta of the subphylum Uniramia? Give an example for each.
1- Coleoptera - beetles
2- Diptera - true flies
3- Lepidoptera - moths and butterflies
4- Hymenoptera - ants, bees, and wasps
Explain the body of the subphylum Crustacea
5 segmented regions = head and long trunk with thorax and abdomen
Explain the head of the subphylum Crustacea (2)
Head has 5 pairs of appendages including 2 pairs of antennae
Cephalic shield or carapace present
Explain the larval form of the subphylum Crustacea
Nauplius (unsegmented w/ single eye) larva with 3 pairs of appendages (even species that hatch later will still go through this stage)
What are the 5 class of the subphylum Crustacea? Give examples
1- Branchiopoda - brine shrimps and water fleas 2- Ostracoda - ostracods 3- Copepoda - copepods 4- Cirripedia - barnacles 5- Malacostraca - crabs and shrimps
Explain the body of the class Malacostraca of the subphylum Crustacea (3)
Thorax has 8 segments
Abdomen has 6-7 segments and telson (last segment)
Appendages on 6th abdominal segment is flattened to form uropods (tail fan)