Module 11 Spiders

Question 1

taxonomy of spiders

Answer 1

Kingdom Animalia
Phylum Athropoda
Subphylum Chelicerate
Class Merostomata
Class Arachnida

Question 2

subphylum Chelicerata key characteristics

Answer 2

chelicera: 1st paired appendage before mouthparts
lack antennae
tagmata: cephlathorax (head/thorax fusion) and abdomen
4 pairs of legs

Question 3

class Merostomata species and characteristics

Answer 3

horseshoe crab: Limulus polyphemus
copper-based blood
limulus amebocyte lysate (LAL) is extracted from blood and used to test for presence of bacteria in blood
red knot birds feed on their eggs

Question 4

class Arachnida species and characteristics

Answer 4

spiders, ticks, mites, scorpions
prosoma (cephlathorax): pair of chelicerae, pair of pedipalps, 4 pairs of walking legs
opisthosoma (abdomen)

Question 5

order scorpiones

Answer 5

ancient group
tropical/subtropical or arid environments
carry young on back
most not aggressive
nocturnal

Question 6

scorpion anatomy

Answer 6

venemous sting (25 sp)
large pedipalps with telson to crush prey and inject venom

Question 7

medical importance of scorpions

Answer 7

localized swelling or pain, blood-filled blisters, and sloughing of skin
18 spp in texas
systemic: pain, numbness, difficulty swallowing, muscle spasms
allergic reactions

Question 8

prevention and control of scorpions

Answer 8

remove debris
slightly raise homes
borax and diatomaceous earth
protective clothing

Question 9

order Uropygi

Answer 9

whip scorpions/Vinegaroons
whip-like tails
not poisonous but can spray vinegar-like acid

Question 10

order Solifugae

Answer 10

solpugids, sun-spiders, etc
typically nocturnal
urban legends for large size but actually only 5 in
rapid movement
powerful chelicerae
can bite but not poisonous

Question 11

order Araneae

Answer 11

spiders
all produce silk for webs
8 eyes

Question 12

mating for spiders

Answer 12

sperm stored in palp in male then transferred to spermatheca duct in females
males perform special dances to attract females but then die shortly after

Question 13

development of spiders

Answer 13

occurs within silken egg sac
egg - spiderlings - adult
live only about 1 year

Question 14

spider envenomation

Answer 14

araneism: being bit by spider

venom injected by chelicerae but varies greatly among taxa

Question 15

tarantulas

Answer 15

most not very toxic
Texas Brown Tarantula (pet)
urticating hairs: barbed hairs on abdomen can penetrate human skin and cause mild reactions

Question 16

Austrialian Funnel-web spider

Answer 16

considered one of most deadly spiders in world
Genera Atrax and Hadronyche
atracotoxins
envenomation: reaction to the toxin and pain from the bite; fangs are hardened and large (can go through a toenail)

Question 17

loxosceles

Answer 17

aka Fiddle-back, Brown recluses, or violin spiders

behavior: nocturnal, rely on venom not webs

Question 18

loxoscelism

Answer 18

disease from being bit by a brown recluse
tissue damage (sphingomyelinase D destroys cells)
systemic: fever, nausea/vomiting, joint pains, hemolysis intravascular coagulation, renal failure

Question 19

black widow

Answer 19

Latrodectus mactans
sexual dimorphism
shy, close to ground, messy webs
reproduces 200 eggs per sac (10 in lifetime)

Question 20

brown widow

Answer 20

Latrodectus geometricus
sexual dimorphism
dorsal: 3 pairs of irregular spots
ventral: hourglass (dull orange)
less severe symptoms than Black widow

Question 21

latrodectism

Answer 21

syndrome caused by bite of any Latrodectus sp
pain, nausea/vomiting, faintness, cramps, profuse sweating, spasms of jaw muscle
fatality in 5% of cases

Question 22

prevention and control of spiders

Answer 22

don't handle spiders!
remove spider webs
pesticides
protective clothing
be cautious of standing material