Arthropoda Flashcards
Summarize phylum arthropoda
Coelomate protostomes
Most diverse
Segmented bodies , a chitinous cuticle and jointed appendages
Summarize subphylum trilobita
Extinct
Chitin exoskeleton
3 tagmata- Head, Trunk and pygdium
head has antennae, eyes, mouth 4 pairs of appendages and a hypostome instead of mouthparts
Summarize subphylum Chelicerata
Very old group
Spiders, mites, ticks, horseshoe crabs and sea spiders
2 tagmata
Describe subphylum cheliceratas tagmata
- prosoma/cephalothorax
used for feeding
eyes, no antennae 3 types of legs - chelicerae, pedipalps and walking - opithosoma/abdomen
Digestive, respiratory and reproductive organs
What are the 3 classes in subphylum chelicerata?
Pycnogonida
Merostomata - horseshoe crabs
Arachnida - mites/ticks/etc.
Summarize class arachnida
Very diverse
Diverse body types
Terrestrial
2 tagmata
True or false: Most arachnids are predaceous
True
What are the 4 orders of arachnida?
Araneae - spiders
Scorpiones- scorpions
Opiliones - harvestmen
Acarina - mites and ticks
List key points of Araneae body
Compact
Unsegmented cephalothorax and abdomen
Chelicerae with terminal fangs
poison glands
pedipalps
4 walking legs
How do Aranea catch prey?
They are all predaceous, but methods vary: they may chase, ambush or trap prey in web
What is unique about Aranea digestion?
Begins externally, their venom liquifies the inside of prey and is then brought into the stomach and absorbed in the gut
What are the sensory organs found in Araneae?
Simple eyes, lens optic rod and retina
Sensory satae- hair like projections that help with sensing vibrations and other stuff
briefly describe Araneae mating practices
The courtship ritual takes place first where the male spins a small web and then deposits a drop of sperm which is stored in pedipalp
Pedipalp is then inserted into the females genital opening and the female lays eggs in a cocoon
Briefly describe the process of web spinning
There are 6-8 spinnerets with silk glands, they produce different types of silk for different types of webs
Silk is stronger than steel
Briefly describe the anatomy of order Scorpiones
Short cephalothorax with the chelicerae, pedipalps legs and eyes
Chelicerae are enlarged and pincerlike
Opisthosome - pre abdomen and then post abdomen with stinger
Stinger that inject venom
Pectines which are used in sex recognition and to explore the ground
Briefly describe scorpiones mating
Courtship is long, involves a dance where the female tests the males strength and then the male places his sperm down and puts the female overtop
Briefly describe scorpione development
Vivparous, females brood young in reproductive tract
can produce upwards of 100 young
Spend the first year on mothers back
Summarize Order opiliones body structure
Prosoma broadly joins the opisthosoma, body presents ovoid
4 pairs of long and spindly legs with tiny claws
Predatory
Summarize Acari anatomy
Completely fused cephalothorax and abdomen
Capitulum with chelicerae, pedipalps and hypostome
adults have 8 legs and larvae have 6
List some unique features of ticks
Parasites for life
Feed on blood
Larger than mites
Why are female ticks less sclerotized than males?
To allow for more expansion as more blood is needed for them to have energy for reproduction, which occurs on host before they drop down to lay eggs
What are the 4 classes of myriapoda?
Diplopoda - millipedes
Chilopoda - centipedes
Symphyla
Pauropoda
How many tagmata are present in Myriapoda?
2, head and trunk, paired appendages on most if not all trunk segments
What are key differences between millipedes and centipedes?
Centipedes have 1 set of legs/ segment and millipedes have 2
millipedes are less active
Centipedes are flatter
