Phylum: Nematoda pseudocoelomate “Radiata” Deuterostomia Protostomia Porifera Cnidaria Chordata Mollusca Ctenophora Phoronida Annelida Ectoprocta Arthropoda Rotifera Nematoda Brachiopoda Nemertea Echinodermata Platyhelminthes “Radiata” Deuterostomia Protostomia Bilateria Phylum: Nematoda pseudocoelomate Eumetazoa Metazoa Ancestral colonial flagellate

Phylum: Nematoda (formerly Aschelminthes) Kingdom: Animalia Phylum: Nematoda (formerly Aschelminthes) non-segmented, smooth worms tapered at both ends bilateral symmetry >80,000 species described most common soil inhabitant 15,000 parasitic species generally less than 5 cm (some parasitic ones longer) covered in thick, tough, protective cuticle cuticle is a syncitial epidermis molt several times during lifespan triploblastic pseudocoelomate- 1st group to evolve a body cavity

Phylum: Nematoda (formerly Aschelminthes) Kingdom: Animalia Phylum: Nematoda (formerly Aschelminthes) pseudocoelomate- coelom partially lined with mesoderm

Advantages of Evolution of a Body Cavity fluids moving within cavity can function as circulatory system fluid in cavity makes body rigid allowing for muscle driven body movement, a “hydrostatic skeleton” organs can function without being deformed by body movement food movement not controlled by locomotion of animal making digestion and waste removal more efficient

Phylum: Nematoda (formerly Aschelminthes) Kingdom: Animalia Phylum: Nematoda (formerly Aschelminthes) complete digestive system one-way digestion (mouth and anus) tube within a tube nervous system sensory structures and ganglia at head nerve ring with ganglia around the pharynx ventral and dorsal nerve cords reproduction is sexual most have separate males and females (dioecious) reproductive organs in body cavity females release chemical attractants

Phylum: Nematoda (formerly Aschelminthes) Kingdom: Animalia Phylum: Nematoda (formerly Aschelminthes) locomotion longitudinal muscles under epidermis no circular muscles can only undulate side-to-side (whip-like motion) no cilia “hydrostatic skeleton” aids in movement excretory system waste moved via fluid in body cavity may have excretory ducts/pores as well as gland cells for waste removal no respiratory or circulatory system gas exchange by diffusion food and nutrients distributed via fluid in body cavity

Phylum: Nematoda (formerly Aschelminthes) Kingdom: Animalia Phylum: Nematoda (formerly Aschelminthes) cross-section

Phylum: Nematoda, Genus: Ascaris Ascaris lumbricoides parasite of humans that causes ascariasis largest intestinal roundworm (15-35 cm) can block intestine, bile duct, pancreatic duct in tropical, sub-tropical areas with poor sanitation caused by accidental ingestion of fertilized eggs most common human helminth infection worldwide infection easily treated with anti-helminthic drugs.

hookworms attached to intestinal mucosa Phylum: Nematoda Hookworms hookworms attached to intestinal mucosa adults attach themselves to intestinal mucosa feed off of blood can cause severe anemia humans contract when larval form bores through skin after contact with contaminated soil treatment: freezing if still on skin, anti-helminthic drugs

Phylum: Nematoda Pinworms Beware the 10 second rule! geographically found everywhere, common here common in school age children, spread by oral-fecal route adult male 1-3 mm, female 8-13 mm live in large intestine eggs ingested hatch in small intestine, then migrate to large intestine to mature eggs can survive 2-3 weeks outside human body treatment: anti-helminthic drugs kill larvae and adult, not eggs Beware the 10 second rule!

Phylum: Nematoda Trichinella spiralis causes trichinosis larvae encysted in striated muscle cysts formed by host immune response larvae passed to another organism when undercooked meat is eaten in new host, cyst digested in stomach releasing worm, then adult develops in intestine adult worms deposit larvae in lymph vessels and wall of intestine larvae migrate throughout body larvae that make it to muscle encyst in their new host

Phylum: Nematoda Trichinella spiralis causes trichinosis humans can get from eating undercooked pork most damage of infection is when 1/2 billion larvae bore through the body at once severe cramping, fever, anemia, weakness some victims may have permanent muscular damage; others may die prevention: thoroughly cook pork, freeze pork rare in developed countries

Phylum: Nematoda Trichinella spiralis causes trichinosis

Phylum: Nematoda Filaria worms significant in human disease intermediate host (vector) is arthropod definitive host is a vertebrate cause of... elephantiasis in humans heartworm in dogs

Phylum: Nematoda Filaria worms: Wuchereria bancrofti causes the disease elephantiasis found in tropical and subtropical areas spread by bite of certain mosquitoes adult worms live in lymphatic system accumulate to large numbers and block lymph flow causes fluid accumulation, swelling, especially in the lower extremities

filaria worms cause the disease elephantiasis

Just FYI:

Phylum: Nematoda Filaria worm causes heartworm in dogs intermediate host = mosquito definitive host = dog fatal to dog

Phylum: Rotifera pseudocoelomate “Radiata” Deuterostomia Protostomia Porifera Cnidaria Chordata Mollusca Ctenophora Phoronida Annelida Ectoprocta Arthropoda Rotifera Nematoda Brachiopoda Nemertea Echinodermata Platyhelminthes “Radiata” Deuterostomia Protostomia Bilateria Phylum: Rotifera pseudocoelomate Eumetazoa Metazoa Ancestral colonial flagellate

Kingdom: Animalia Phylum: Rotifera microscopic (50µm - 2mm long) usually free-living, in moist soil or aquatic environments corona double crown of cilia at anterior end look like rotating wheels when they beat draw water current into mouth for feeding & locomotion foot at posterior end when feeding, attaches to surface nearby cement gland generates the adhesive mastax complicated muscular pharynx seven hard jaw-like structures crush food

Kingdom: Animalia Phylum: Rotifera pseudocoelemate complete digestive system have excretory and reproductive systems no circulatory or respiratory system reproduction can be sexual or by parthenogenesis parthenogenesis- in some species females produce 2 different kinds of diploid eggs, female and male, that develop without fertilization to diploid adults in some species, eggs can develop as dwarf males that cannot even feed themselves, only survive long enough to produce sperm to fertilize females (sexual dimorphism- sexes take on 2 different forms)

cilia beat in opposite directions to create current Kingdom: Animalia Phylum: Rotifera cilia beat in opposite directions to create current (cement glands)

The Table for Nematoda: Symmetry: bilateral Segmentation: none Mesoderm present: yes, triploblastic, has only longitudinal muscles Type of body cavity: pseudocoelomate; fluid filled pseudocoel enclosed by cuticle forms hydrostatic skeleton Ciliated larva: have larva that molt (shed cuticle as they grow) Protostome: no? (this is under debate among scientists, newer molecular evidence may revise this) Cleavage/cells: determinate Nervous system: present; 2 nerve cords (dorsal & ventral)

The Table for Nematoda: Digestive system: complete one-way system (mouth & anus); pharynx usually muscular; some heterotrophs but mostly parasites Excretory system: yes, excretory ducts and pores to eliminate waste, some have gland cells and/or canal systems, too Reproductive system: sexes usually separate (dioecious); male reproductive tract opens to rectum forming common exit called the cloaca; female reproductive tract opening separate from digestive tract Circulatory system: none Members: hookworms, pinworms, common roundworm, trichinella Habitat: moist soil; the most numerous inhabitant of the soil; also found in aquatic environment; some parasites Relationship to other phyla: N/A

The Table for Rotifera: (If nothing is listed for a category, assume it is the same as for Nematoda.) Reproductive system: sexual or by some by parthenogenesis (produce diploid eggs that grow to diploid adult without fertilization); some exhibit sexual dimorphism producing degenerate dwarf males that live only long enough to fertilize eggs Members: rotifers Habitat: freshwater and marine environments, moist soil Relationship to other phyla: cuticle suggests rotifers are close relatives of roundworms