Journal. Differentiate between pleopods and periopods in a crayfish. Please turn in Crayfish Dissection Lab if you haven’t already done so. Journal. Choose one of the questions below to answer: How are hunting spiders different from web spinning spiders?
a. Chelicerae- first pair, pincer-like, feeding/fangs
b. Pedipalps- second pair, sensing, feeding, reproduction
3. No antennae
4. 8 walking legs
7. Dioecious- male fertilizes eggs as female sheds them into a shallow hole. No brooding occurs.
Horseshoe crab vision
EX: Spiders, mites, ticks, scorpions
** Water conservation is a major concern for many terrestrial animals. Most wastes excreted in solid form to prevent water loss.
4. 6-8 Simple eyes- sense light & movement
a. Black widow- shiny black w/red hour glass on ventral surface of abdomen.
b. Brown Recluse- violin shape on cephalothorax
Myth: Daddy long legs are the most venomous spiders in the world but lack mouthparts to inject venom.
Scorpions world but lack mouthparts to inject venom.
b. Venom gland & stinger in tail
c. Modified pedipalps- pincers for grasping food/defense
d. Courtship dance where male “lays” sperm case and female “sits” on case to pick up sperm
e. 20-40 young brooded by mother on her back for about 1 month
Mites- 1mm or less in size female “sits” on case to pick up sperm
a. Many are ectoparasitic- feeding on blood or tissue
b. Some permanent (follicle mite)
c. Some temporary (chigger)
Ticks- up to 3cm in length female “sits” on case to pick up sperm
a. All ectoparasites.
b. Bodies expand as they feed.
c. Breeding occurs on host.
d. Female drops off & lays eggs.
e. Can carry disease.
Economic/Environmental Significance female “sits” on case to pick up sperm
a. Carry/cause disease
1. Rocky Mountain Spotted Fever- ticks
2. Lyme’s Disease- ticks
Brown Recluse female “sits” on case to pick up sperm
Day 1 female “sits” on case to pick up sperm
Day 10 female “sits” on case to pick up sperm