Morphological structures of digenetic flukes?
- attachment organs (oral sucker)
- blind ceca (hermaphroditism)
- testes (tandem v parallel)
- cirrus (penile structure)
- vitelline glands
- genital pore
What is the infective stage of most flukes?
Flukes commonly use what intermediate host?
- Type of fluke which has a tubular body and separate sexes (dioecious)
- Has no 2nd IH
- Matures in blood of DH
- Eggs have lateral spine
Two main types of cestodes?
pseudophyllidea and cyclophyllidea (true tapeworm)
Characteristics of cestodes?
- Endoparasites with indirect life cycle
- Absorb nutrients through body wall
- Variable sizes
Single scolex NOT invaginated (usually an invertebrate IH)
Single invaginated scolex (usually vertebrate IH)
Brood capsules with 100-1000 protoscolices.
- may be unilocular or multilocular
Single, non-invaginated scolex attached to fluid-filled bladder via segmented stobila
Characteristics of all nematodes?
- tubular bodies with body cavity
- separate sexes (dioecious)
- may have direct or indirect life cycle
- complete digestive system
Nematode life cycle? (generally)
- egg/larvae --> L1-5 (L3 usually infective) --> larvaie in IH (if indirect) --> adults in DH
Characteristics of rhabditoidea (strongyloides)?
- tiny worms (most free-living, some facultative)
- only females are parasitic
Characteristics of trichostrongyloidea?
- hairlike worms, tiny mouths
- males have well-developed copulatory bursa
- direct lifecycle
- usually in GI tract
- ostertagia and haemonchus are most common
Characteristics of Metastrongyloidea?
- medium sized worms
- indirect life cycle
- males have 2 equal spicules
Characteristics of strongyloidea?
- medium sized with large mouths
- males have prominent copulatory bursa and 2 equal spicules
- direct life cycle (often with extensive larvae migration)
Characteristics of oxyuroidea?
- double-bulbed esophagus
- female tail: drawn to extreme point
- male tail: caudal alae, single spicule
- ONLY PARASITE OF OMNIVORES OR HERBIVORES (NOT CARNIVORES)
Characteristics of ascaroidea?
- very large (>6") with 3 robust anterior lips
- direct life cycle with larval migration
- males are without copulatory bursa
- may or may not have alae
- large egg with thick central morula
Characteristics of spiruroidea?
- medium-sized worms with prominent mouth
- indirect life cycle (arthopod IH)
- males have caudal alae, 2 unequal spicules, and twisted posterior ends
Characteristics of trichuroidea? (whipworms)
- short, fat posterior ends, long whip-like anterior end
- beaded esophagus
- males have no bursa and no alae
- direct life cycle
- "Stewie head" eggs