Activity 19_ppt Phylum Nematoda

Activity 19: Phylum Nematoda Pre-lab Discussion

NEMATODES Unsegmented roundworms Most successful among worms

HABITATS Live in all kinds of habitats   

Seawater Fresh water terrestrial

MODES OF LIVING FREE LIVING (Turbatrix aceti - vinegar eel) - these free-living roundworms exist by feeding on bacteria and fungi found in the sediments of nonpasteurized vinegar

Vinegar eels in vinegar

PARASTITIC

MODE OF NUTRITION some can subsist in organic detritus others are scavengers

BASIC BODY PLAN Body is covered by nonliving cuticle Lack cilia or flagella (+) pseucocoelom – lacks peritoneal lining (+) COMPLETE digestive tract Mostly dioecious Males usually smaller than females

PARASITIC SPECIES THAT ARE IMPORTANT TO MAN Ascaris

PARASITIC SPECIES THAT ARE IMPORTANT TO MAN Hookworms

Cutting plates

mouth

bursa

PARASITIC SPECIES THAT ARE IMPORTANT TO MAN Pinworms

Head with cephalic alae

A. vermicularis in sigmoid colon

PARASITIC SPECIES THAT ARE IMPORTANT TO MAN Trichina worms

Trichuris trichiuria Trichinella spiralis Encysted larva

CLASSIFICATION Class Aphasmida – without PHASMIDS  

Trichuris (whipworm) Trichinella (trichina worm)

Class Phasmida – with PHASMIDS and AMPHIDS   

Ascaris (intestinal roundworm) Enterobius (pinworm/seatworm) Ancylostome (hookworm)

STUDY THE FOLLOWING SPECIMEN: Preserved Ascaris Ancylostoma Enterobius Trichiuris Trichinella