Module 11 Spiders Flashcards
taxonomy of spiders
Kingdom Animalia Phylum Athropoda Subphylum Chelicerate Class Merostomata Class Arachnida
subphylum Chelicerata key characteristics
chelicera: 1st paired appendage before mouthparts
lack antennae
tagmata: cephlathorax (head/thorax fusion) and abdomen
4 pairs of legs
class Merostomata species and characteristics
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
class Arachnida species and characteristics
spiders, ticks, mites, scorpions
prosoma (cephlathorax): pair of chelicerae, pair of pedipalps, 4 pairs of walking legs
opisthosoma (abdomen)
order scorpiones
ancient group tropical/subtropical or arid environments carry young on back most not aggressive nocturnal
scorpion anatomy
venemous sting (25 sp) large pedipalps with telson to crush prey and inject venom
medical importance of scorpions
localized swelling or pain, blood-filled blisters, and sloughing of skin
18 spp in texas
systemic: pain, numbness, difficulty swallowing, muscle spasms
allergic reactions
prevention and control of scorpions
remove debris
slightly raise homes
borax and diatomaceous earth
protective clothing
order Uropygi
whip scorpions/Vinegaroons
whip-like tails
not poisonous but can spray vinegar-like acid
order Solifugae
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
order Araneae
spiders
all produce silk for webs
8 eyes
mating for spiders
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
development of spiders
occurs within silken egg sac
egg - spiderlings - adult
live only about 1 year
spider envenomation
araneism: being bit by spider
venom injected by chelicerae but varies greatly among taxa
tarantulas
most not very toxic
Texas Brown Tarantula (pet)
urticating hairs: barbed hairs on abdomen can penetrate human skin and cause mild reactions
Austrialian Funnel-web spider
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)
loxosceles
aka Fiddle-back, Brown recluses, or violin spiders
behavior: nocturnal, rely on venom not webs
loxoscelism
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
black widow
Latrodectus mactans
sexual dimorphism
shy, close to ground, messy webs
reproduces 200 eggs per sac (10 in lifetime)
brown widow
Latrodectus geometricus sexual dimorphism dorsal: 3 pairs of irregular spots ventral: hourglass (dull orange) less severe symptoms than Black widow
latrodectism
syndrome caused by bite of any Latrodectus sp
pain, nausea/vomiting, faintness, cramps, profuse sweating, spasms of jaw muscle
fatality in 5% of cases
prevention and control of spiders
don't handle spiders! remove spider webs pesticides protective clothing be cautious of standing material
