ARTHROPODS BIO 104 Exam 3

Phylum Arthopoda “Joint Foot”

Largest Animal Phylum - One million+ species and growing

Major Characteristics of Arthropoda

Joints

Exoskeleton - external skeleton that hardens over time, does not digest well, starts as a liquid carbohydrate made of chitin

Ecdysis - process of secreting a new skeleton

Sclerotization - hardening after the new skeleton emerges

Habitat of Arthopods

Live everywhere

Adult

Sexual maturity/ability to reproduce

Larvae

Eat to store calories and energy

Nymph

Looks like tiny miniature adults that gradually get bigger as they eat

Pupae/Chrysalis

Change over, metamorphic phase into an adult

Ancestor of Arthropods

Phylum Onycophora

Peripatus “Velvet Worms”

Between a segmented worm and arthropod

Subphyla of Velvet Worms

Trilobitamorpha “Trilobites”

Extinct, marine

Subphyla: Chelicerata

“Spiders, Ticks, Scorpions, Mites, etc”

Chelicera

Piercing sucking mouthparts - fangs

Leg # - 8/10 legs

Merostomata (Chelicerata)

“Horseshoe crab” - not an actual crab

Has chelicera

Pycnogonia

“Sea spider” Not an actual spider

Arachnida “Spiders”

Injects, venomous/disease vectors - an animal that when it bites you, it’s saliva delivers a micro-organism that gives you some kind of disease

4 Major Orders of Arachnids

Scorpiones

Opiliones

Acarina

Araneae

Spider that writes name in its web

Web-building spider/Garden Spider

Scorpiones

Scorpions - stinging is not lethal

Opiliones

Daddy long legs/Harvest Men - spider-like but not actual spiders, perfectly harmless, used to be believed to point to where things are

Acarina

Disease vectors, most are blood sucking parasites, causes lyme disease, bite area turns into a bullseye-like mark

Araneae

Silk products (not actual silk) - spiders are ambitory/ambush predators. Does not produce actual silk, is a very resilient protein that can resist the strain of stretching and tearing

Two True Venomous Spiders

Latrodectus mactans - Black Widow

Locosceles reclusa- Brown Recluse

Latrodectus mactans - Black Widow

Only female has red mark, female mates with male and eats it/widows itself, not really lethal but could lead to swelling/pain/dry mouth/headaches and gets worse depending on location

Will be AROUND your house but not in your house

Loxosceles reclusa - Brown Recluse

Indoor spider that lives in closets, drawers, and under bed.

Hemotoxin venom, causes tissue to rot

More problematic

Mandibulata

Mandibles/maxilla - grinding chewing biting mouthparts

Four Classes of Mandibulates

Diplopoda

Chilopoda

Crustacea

Hexapoda

Diplopoda

“Millipedes” (1,000 legged worm)

4 legs (2/side) per body segment

Move very slow

If disturbed, they roll into a ball

Scavengers and decomposers

Chilipoda

“Centipedes” (100 legged worm)

2 legs (1/side) per segment

Venomous, have a red/yellow coloration to them/warning color

Crustacea “Crab, Shrimp, Lobster”

Aquatic

Walking legs - 5 pairs/10 legs

Chelipeds - crab claws

2 pair of antennae - have a short and long pair that reaches out to guide their senses

Respiration via gills

Major Crustacean Groups

Barnacles - filter feeders, sessile

Malacostraca

Major seafood group

• Crabs

• Crayfish

• Lobster

• Shrimp

Insecta “Insects”

3 pairs of walking legs/6 legs

1 pair of antennae

2 pair of wings/4 wings

Major Economic Pro and Con of Insects

1. Pollinators - Trillion dollar industry, food growth

2. Honey 200 mill Kg/yr in US

Wax 5 mill Kg/yr in US - leather, thread, clothes

Silk 25 mill Kg/yr worldwide

Comes from caterpillars

Agriculture Pests

Crops, stored grains, other

Boll weevil

Beetles

Moths

Roaches

Timber/wood product pests

Pine Bark Beetle - only affect and eat live trees

Termite - needs wood touching the ground and needs a moist environment, eats dead wood

BIG drain of cash to exterminate

Moths - will eat holes in wool and fabric

Strongest organism know to exist

Rhinoceros Beetle

Able to carry 850x own weight