Oklahoma City Community College Phylum Nematoda BIO 2215 Oklahoma City Community College Dennis Anderson

Phylum Nematoda 12,000 species Cylindrical body 500,000 possible Cylindrical body Only longitudinal muscles Noncellular cuticle with several layers Pseudocoelomate Mouth and anus

Nematodes Found everywhere Soil Oceans Polar ice Hot springs Parasites of nearly all plant and animal species!

Echinodermata Uniramia Chelicerata Chordata Crustacea Other Chordata Lophophores Crustacea Other Chordata Arthropoda Annelida Hemichordata Mollusca Other pseudocoelomates Nemertea Platyhelminthes Nematoda Ctenophora Cnidaria Mesozoa Placozoa Sarcomastigophora Ciliophora Porifera Apicomplexa Microspora Myxozoa

Embryonic Development Protostome Blastopore becomes mouth Deuterostome Blastopore becomes anus

Fig. 15.1

Nematode Reproductive Systems Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nematode Reproductive Systems

Dioecious

Dorsal and Ventral Nerve Cords

Caenorhabditis elegans Free living nematode Eutely Constant number of cells 959 cells Development of every cell is known Genome sequenced Compare genomes

Nobel Prize for Worms Sydney Brenner C. elegans since 1963 Brenner, Sulston and Horwite awarded Nobel Prize in 2002

Ascaris lumbricoides Roundworm of man 1.2 billion people Many in southeast US Females lay 200,000 eggs a day Unsanitary habits contaminate ground Night soil

Life Cycle of Ascaris Lumbricoides Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Life Cycle of Ascaris Lumbricoides Source: Redrawn From Centers for Disease Control, Atlanta, GA.

Enterobius vermicularis Pin worm 50% of children in US Spread Fecal oral route airborne

Life Cycle of Enterobius Vermicularis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Life Cycle of Enterobius Vermicularis Source: Redrawn From Centers for Disease Control, Atlanta, GA.

Hookworms Anterior end hooks Necator americanus Ancylostoma duodenale Feed on blood Cause anemia

Life Cycle of Necator Americanus Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Life Cycle of Necator Americanus Source: Redrawn From Centers for Disease Control, Atlanta, GA.

Ancylostoma caninum

Cutaneous Larval Migrans Hookworms from dogs and cats

Trichinella spiralis Trichina worm Pigs, bear, dogs, cats, rats and man Trichinosis Encysts in muscles

Life Cycle of Trichinella Spiralis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Life Cycle of Trichinella Spiralis Source: (a) Redrawn From Centers for Disease Control, Atlanta, GA. (b) Photo © Steve Miller

Wuchereria bancrofti Lives in lymphatic system Obstruct lymph to cause swelling Elephantiasis

Elephantiasis

Life Cycle of Wucheria spp. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Life Cycle of Wucheria spp. Fig. 11.15 11-13 Source: Redrawn From Centers for Disease Control, Atlanta, GA.

Loa loa Eye worm

Dracunculus medinesis Fiery serpent

Dirofilaria immitis Dog heart worm

The End