1. Phylum Nematoda
The round worms
They’re EVERYWHERE!!!!!

2. Anatomy of a Nematode No circulatory system Hydrostatic skeleton
Longitudinal muscles

4. Ectoparasitic nematode feeding on a tomato root
Stylet

5. Ascaris lumbricoides - round worm Common mammal parasite
Female
Male
Larva in lung

6. Necator - hookworm

7. Trichinella spiralis - trichinosis
Infection with ingestion of raw/poorly cooked pork
Encysted larva in muscle

8. Enterobius vermicularis - pin worm
Most common human parasitic infection
Most common nematode infection

9. Dracunculus medinensis - filarial worm
The Guinea Worm
Copepod is intermediate host
1. Infected copepod ingested
2. Larvae enter gut wall, mature in deep tissue
3. Female migrates to subcutaneous tissue (~ year)
4. Blister forms and breaks open in water, larvae released,enter copepod

10. Phylum Nematomorpha “thread body” - horsehair worms
free-living as adults
parasitic in arthropods as juveniles
larva
Once included with the Nematodes
Pseudocoelomates, no functional digestive system
adult

11. Segmented body with recurved spines Live in marine mud sediments
Phylum Kinoryncha
“moveable snout”
Segmented body with recurved spines
Live in marine mud sediments

12. Phylum Priapulida “the phallus” Cold water carnivorous marine worms
Burrow head-up in marine mud sediments

13. Live among grains of marine gravels
Phylum Loricifera
Have a circular lorica
Live among grains of marine gravels

15. Phyla with Arthropod Affinities
Clade Panarthropoda
Phyla with Arthropod Affinities
Ph. Arthropoda
Ph. Onycophorana
Ph. Tardigrada

16. Phylum Onychophora “velvet worms” non-jointed walking legs (lobopods)
claw-like processes on appendages
chitinous cuticle (also an arthropod trait)
tracheal system with spiracles
open circulatory system (hemocoel)
large brain

17. Sticky slime and toxic saliva
VORACIOUS PREDATORS
Sticky slime and toxic saliva

18. Phylum Tardigrada “slow stepper” Non-jointed walking legs (lobopods)
Claw-like processes on appendages
Non-chitinous exoskeleton
Body cavity = hemocoel
Rudimentary segmentation
Mouth with sucking pharynx and stylets
Undergo cryptobiosis
Teeny and very cute