Trematodes 2010 - Introduction Digenetic Trematodes have A...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
1 IGENETIC TREMATODES DIGENETIC TREMATODES Dwight D. Bowman Introduction Digenetic Trematodes have A solid body Covered with a syncytium, the tegument, rather than a ciliated epithelium An excretory system composed of flame cells Are typically hermaphroditic Have separate ovaries and testes Oviduct and vas deference have separate terminations, but usually in the same pore or genital opening Capable sometimes of self fertilization, but usually pair with another trematode of the same species Typically bear two suckers, an anterior sucker around the mouth and a posterior sucker that is usually at midbody Oviduct, typically filled with eggs Eggs very often operculate Yolk cells are typically separate from the ovum within the eggshell Egg shell is often brown in color Introduction A vertebrate final host mollusk, intermediate host A mollusk, intermediate host Asexual multiplication in the mollusk (usually a snail) Snails infected by the stage from the egg, a ciliated miracidium In snail have various developmental stages Mother sporocyst Daughter sporocyst edia Redia Ultimately producing cercarial stages that are infective to the vertebrate final host No multiplication occurs in the vertebrate host
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 General Life Cycle It was in 1845, that JJS Steenstrup howed that the stages in the snail were s o ed a e s ages e s a e e the same as those found in the vertebrate Showed that had asexual multiplication in the snails Called the multiplication through two different tages the alternation of generations stages the alternation of generations THE EGG EMBRYONATED EGG
Background image of page 2
3 MIRACIDIUM PENETRATING A SNAIL
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 SNAILS SPOROCYST SPOROCYSTS & REDIAE REDIA
Background image of page 4
5 CERCARIAE CERCARIA METACERCARIA METACERCARIA
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 FINAL HOST INGESTS METACERCARIA F. buski F. hepatica Echinostoma Heterophyes Metagonimus Clonorchis Dicrocoelium Alaria Paragonimus Schistosoma TREMATODE TRANSMISSION WITH THE EXCEPTION OF THE CHISTOSOMES, ALL TRANSMISSION SC S OSO S, S SS O IS VIA INGESTION OF THE METACERCARIA OR MESOCERCARIA STAGE A few of the Intestinal Flukes Fasciolopsis buski Echinostoma Heterophyes Metagonimus Clonorchis
Background image of page 6
7 Fasciolopsis buski Giant Intestinal Fluke Fasciolopsis buski Fasciolopsis buski A very large fluke that lives in the small intestine of humans and pigs in various Southeast Asian countries and China. Also found in people in Hawaii Eggs very similar to those of the large liver fluke, Fasciola hepatica he fe cycle volves eggs passed in the feces development of the miracidia within The life cycle involves eggs passed in the feces, development of the miracidia within the egg, hatching (takes about 3-7 weeks), infection small planorbid snails ( Segmentina , Hippeutis, Polypilus, and Gyraulus ), sporocysts, first and second generation rediae, and cercariae.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/11/2011 for the course BIOMI 3310 at Cornell University (Engineering School).

Page1 / 41

Trematodes 2010 - Introduction Digenetic Trematodes have A...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online