Biomaterial Database

Comparative observations on cercariae and metacercariae of Echinostoma trivolvis and Echinoparyphium sp. 1998

B Fried, and B A Frazer, and I Kanev

Department of Biology, Lafayette College, Easton, Pennsylvania 18042, USA.

Comparative observations were made on cercariae of Echinoparyphium sp. from Physa gyrina in Charlie's pond, Stokes County, North Carolina and cercariae of Echinostoma trivolvis from Helisoma trivolvis in Northampton County, Pennsylvania. The cercaria of Echinoparyphium sp. has 43 collar spines, lacks penetration and paraesophageal glands, and has a conical tail without fin folds. The cercaria of E. trivolvis has 37 collar spines, penetration and paraesophageal glands, a finger-like process at the tip of the tail and fin folds. The length of the cercarial body and tail of E. trivolvis was significantly greater than that of Echinoparyphium sp. Cercariae of both species encysted in Biomphalaria glabrata snails in single and concurrent infections. In concurrent infections with a single cercaria of each species, 2 encysted metacercariae were adjacent to each other in the saccular kidney of the snail at 24 hr postinfection. The diameter of encysted metacercariae of E. trivolvis was significantly greater than that of Echinoparyphium sp. Echinoparyphium sp. metacercariae excysted at 39 C in an alkaline trypsin-bile salts medium used previously to excyst E. trivolvis. The length of excysted metacercariae of E. trivolvis was significantly greater than that of Echinoparyphium sp.

UI	MeSH Term	Description	Entries
D009657	North Carolina	State bounded on the north by Virginia, on the east and Southeast by the Atlantic Ocean, on the south by Georgia and South Carolina, and on the west by Tennessee.
D004449	Echinostoma	A genus of intestinal flukes of the family Echinostomatidae which consists of many species. They occur in man and other vertebrates. The intermediate hosts are frequently mollusks.	Echinostoma ilocanum,Euparyphium ilocanum,Fascioletta ilocanum,Echinostoma ilocanums,Echinostomas,Euparyphium ilocanums,Fascioletta ilocanums,ilocanum, Echinostoma,ilocanum, Fascioletta,ilocanums, Euparyphium
D005618	Fresh Water	Water containing no significant amounts of salts, such as water from RIVERS and LAKES.	Freshwater,Fresh Waters,Freshwaters,Water, Fresh,Waters, Fresh
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012908	Snails	Marine, freshwater, or terrestrial mollusks of the class Gastropoda. Most have an enclosing spiral shell, and several genera harbor parasites pathogenic to man.	Snail
D014200	Trematoda	Class of parasitic flukes consisting of subclasses Aspidogastrea and Digenea. The digenetic trematodes are the only ones found in man. They are endoparasites and require two hosts to complete their life cycle.	Aspidogastrea,Digenea,Flukes,Petasiger,Echinochasmus,Himasthla,Paryphostomum,Troglotrema,Aspidogastreas,Digeneas,Fluke,Himasthlas,Paryphostomums,Petasigers,Trematodas,Troglotremas