NEMATOLOGY 100
Laboratory Exercise 8
Rev. 10/24/2008
Purpose: Migratory endoparasitic nematodes: morphology, anatomy, biology, feeding habits -- Hoplolaimidae, Pratylenchidae (Tylenchida, Tylenchoidea)
1. Slide presentation of characteristics.
2. Hand-pick live adults of the Helicotylenchus sp. and Pratylenchus sp. Draw the nematodes, observing the following characteristic features:
a) stylet
length and morphology.
b) esophagus,
type and anatomy, nature of postcorpus
interface with intestine.
c) male
and female reproductive structures.
d) general
shape when heat-relaxed.
3. Key the specimens of Pratylenchus provided to species using the key to the nine common Pratylenchus species of California.
4. Note the taxonomic position of these nematodes in the order Tylenchida.
5. Examine descriptive charts of the migratory endoparasitic nematodes in the Hoplolaimidae and Pratylenchidae.
6. Movie
Behavior of Pratylenchus penetrans
7. Study photographs of characteristics and damage by migratory endoparasites: Pratylenchus
8. Lab Project:
Powerpoint presentation: Nematodes as Bioindicators.
9. Homework Assignment:
NEMAPLEX Exercise
Main Menu:
Select...Biology and Taxonomy
Select..Phylogenetic Classification
Select...Tylenchida
Select...Hoplolaimidae
Review Hoplolaimus including some of
the species
Review Scutellonema including some of
the species
Select...Pratylenchidae
Review Pratylenchus including some of
the species
Return to
Main Menu
10. NEMABASE Exercise
Determine the host range for
the genus Pratylenchus.
In Nemabase select "All
Plants" and "Genus" Pratylenchus. Set
"Host" filter to Host. Process.
NEMATOLOGY 100
Key to the Nine Common Pratylenchus
Species in California
| 1. | Monosexual species, no sperm in spermatheca, males rare or unknown. | 2 |
| Bisexual species, sperm in most spermatheca, males common. | 7 | |
| 2. | Very large, round stylet knobs, stylet averages 19 µm in length; V% 82-89; 2 lip annules | P. brachyurus |
| Stylet knobs oval or flattened, stylet generally less than 19 µm long | 3 | |
| 3. | Tail tip annulated, 3 lip annules | P. crenatus |
| Tail tip smooth | 4 | |
| 4 | Lip annules 2 | 5 |
| Lip annules 3 | 6 | |
| 5 | Average V%=84, lip annules about same width; stylet knobs often flattened; vulval lips somewhat smooth | P. neglectus |
| Average V%=78%, anterior lip annules markedly narrower than posterior; vulval lips protrude somewhat | P. scribneri | |
| 6 | Tail normally truncate, stylet averages 18 µm in length; V% averages 76; normally assumes a "J" or "C" shape when heat killed | P. zeae |
| Tail narrowly rounded, stylet averages 16 µm in length; V% averages 71; normally almost straight when heat killed | P. thornei | |
| 7 | Lip annules 2, occasionally 3 on one side | P. coffeae |
| Lip annules 3, occasionally 4 on one side | 8 | |
| 8 | Spermatheca normally round, posterior uterine branch 1 to 1.5 body widths long; large stylet knobs | P. penetrans |
| Spermatheca normally oval, posterior uterine branch generally greater than 2 body widths long; moderate sized stylet knobs | P. vulnus |