Nematodes, Annelids, and Molluscs Flashcards
What organism is Phylum Nematoda?
Roundworms
What are nematodes (roundworms) like?
Cylindrical body hooked at both ends, bilaterally symmetrical, triploblastic, pseudocoelom, no segmentation, complete digestive system, hydroskeleton, no circulatory or respiratory system, simple nervous and excretory system.
How do nematodes transport nutrients?
They lack a circulatory system but have an alimentary canal, so they transport nutrients by fluid in the hemocoel
Trichinella spiralis
A parasite that can be acquired by humans eating undercooked pork, becomes encysted in human muscle tissue and organs and causes trichinosis
Sexual reproduction in nematodes?
Primarily sexual
Endotokia matricida
Intra-uterine birth causing maternal death
Phylum Annelida organism?
Segmented worms that live in marine, freshwater, and damp soil habitats
General characteristics of annelids
-Segmented
-Bilaterally symmetrical
-Elongated Bodies
-Protostomes
-Possess a coelom
-Complete digestive system
-Closed circulatory system
-CNS
-No appendages
-Each segment possesses setae
-hydrostatic skeleton
-Complete digestive system
-Closed circulatory system with beating heart
Setae
Small bristle-like appendages used for locomotion
What excretory system do annelids use?
Nephridia (similar to vertebrate kidneys)
What organisms included in P. Annelida, Class Polychaeta?
Bristle worms, Polychaetes
What are polychaetes?
A diverse group of marine worms; polychaete means many setae
Polychaete general characteristics
-segmented
-bilaterally symmetrical
-coelomate
-distinct head w/ eyes, antennae, and sensory palps
-Parapodia with setae on each segment
-closed circulatory system
-complete digestive system
-respiration through skin, gills, or parapodia
-nephridia for excretion
Parapodia
Appendages on polychaetes that can be used for swimming and gathering food, can also be used as gills or for protection
What organism for P. Annelida Subclass Hirudinea?
Leeches