The Eukaryotes 12d: Animals Helminths & Arthropods

reduced or no digestive system reduced nervous system Helminths reduced or no digestive system reduced nervous system no or reduced locomotion life cycle is usually complex For the CDC versions of parasite life cycles http://www.dpd.cdc.gov/dpdx/Default.htm

23.13 Phylum Platyhelminthes = flat worms Class Cestoda = tapeworms 2 body parts hermaphroditic 23.13

23.14 Taenia saginata = beef tapeworm T. solium = pig tapeworm cysticercus (immature form in muscle) “dead-end host” Def. host

Echinococcus granulosus

Diphyllobothrium latum = broad fish tapeworm Def. host

23.16 Phylum Platyhelminthes = flat worms Class Trematoda = flukes snails are usually the intermediate hosts usually hermaphroditic except schistosomes 23.16

23.17 Schistosoma = blood fluke 2 sexes Infects >200 million people/year 2 sexes 23.17

Swimmer’s itch Cercaria in skin

Fasciola = sheep liver fluke (Dhost: sheep & other grazing animals; humans are “accidental”) hermaphroditic 23.17

Phylum Nematoda

Ascaris hookworms: Necator & Ancylostoma

Enterobius vermicularis = pinworm

Trichinella

microfilariae Wucheria

Dracunculus medinensis = guinea worm

Anisakine worms: Anisakis & others (~2 cm long) Def. host

Phylum: Annelida (segmented worms) Class: Hirudinae (leeches) FDA approved Hirudo medicinalis leech jar

Arthropod vectors 23.24 Arachnids Insects

Considered “diseases” Sarcopti scabiei = scabies, mange Can be STI

Phthirus pubis = crab/pubic louse Pediculus capitis Lice: Pediculus spp. Phthirus pubis = crab/pubic louse

Maggot therapy - for treating non-healing wounds. Blowflies (Calliphoridae) usual species: Phaenicia sericata (green blowfly) (FDA approved) 1. They clean the wounds by dissolving dead and infected tissue ("debridement"); 2. They disinfect the wound (kill bacteria); 3. They speed the rate of healing. For more info: http://www.medicaledu.com/maggots.htm#Current status of maggot therapy (maggot)