Exam 2 (Tropical Arthropods) Flashcards
1
Q
Phylum: Arthropoda
A
- segmented body plan with hardened exoskeleton composed of alpha-chitin
- tagmosis of segments into body regions
- paired jointed appendages
- compound eyes
2
Q
Arthropods are ancient
A
- origins in Cambrian
- first true scorpions and insects
- most likely the first animals to conquer land
- first in flight
- survived two major mass extinctions
3
Q
Arthropods Today
A
- over 3/4 of all species on earth
- have near global distribution
- found in nearly all habitat types (except terrestrial arctic situations)
- integral members of nearly all food-chains and ecosystems
4
Q
Tropical Arthropods
A
-have the highest diversity of arthropods
5
Q
How are arthropods distinguished primarily?
A
by mouthparts
6
Q
Tropical Arachnids
A
- two body regions prosoma and opisthosoma
- chelate mouthparts
- 8 legs
- pedipals
- largest groups (araneae, acari)
- several smaller arachnid orders have highest diversity in tropics
7
Q
Order: Araneae
A
- Chelicerae modified into fangs
- abdomen with silk producing spinnerets
8
Q
Mygalomorphiae
A
Tarantulas and relatives
- fangs point straight down and stab during prey capture
- greatest diversity in tropics
9
Q
Araneomorphiae
A
typical spiders
- fangs come together in a pinching motion
- greatest diversity in the tropics
10
Q
Tropical Insects
A
- three body regions
- six legs
- 1 pair of antennae
- dicondylic jaws
- most with 2 pairs of wings
- many insects have close co-evolution with plants
11
Q
Order: Blattodea
Infraorder: Isoptera
A
Termites
- citizen roaches: highly social and morphologically reduced cockroaches
- cast systems (workers, soldiers and reproductive King and Queen)
- digest cellulose via endosymbiotic microbionts
- consume an estimated 50-100% of the dead wood in forests
- absolutely essential in mineralization of plant material
12
Q
Coleoptera
A
- the largest order of eukaryote animal
- recognized by hardened wing cases called elytra
- ecologically diverse (predators, herbivores, fungivores, parasitoids)
- most belong to the family: Curculionidae: the weevils
13
Q
Order: Hymenoptera
Family: Formicidae
A
- easily recognized by constricted abdomen: petiole
- geniculate antennae
- highly social
- cast system: reproductive queen and workers
- the larger the colony, the more cast polymorphism
14
Q
Why are ants the master of the tropics?
A
- sheer biomass (30% of all animal biomass)
- more than 2,000 species in 50 families of arthropods mimic ants
- hundreds of plants in 40 families have evolved special structures to house ants
- thousands of hemipteran species form a special alliance of safety in exchange for honey dew
- clear keystone consumers having affected the evolution of so many other species
15
Q
Keystone Species
A
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
