Cell type

Thick shell 

Medium thick shell

Thin shell

No shell

Single Cell

Ascarididoidea:

• Toxocara

• Toxascaris

• Ascaris

• Parascaris

Trichruoidia: (double plugs)

• Trichuris

• Capillaria

Coccidian oocysts:

• Isospora

• Toxoplasma

• Eimeria

Flagellates (trophozoites):

• Giardia
• Chilomastix
• Trichomonads

Amebae (trophozoites)

Ciliates:

• Balantidium coli

Segmented Blastomere

Ascarids (old feces):

• Two or more cells

Nemahelminthes:

• Oxyuroidea (flat-sided)

• Oxyuris (single 

• plug)

• Diphyllobothrium

• Spirometra

Strongylid eggs:

• Strongyloidea

• Trichostrongyloidea

Mite eggs (without larva):

Vermiform  Larva

Ascarids in old feces

• Larvated egg

Metastrongyloidea:

• Metastrongylus

Trematodes (operculated shell)

Rhabiditoidea:

• Strongyloides

• Strongyloidea

• Trichostrongyloidea

Vermiform larvae:

• Rhabditoidea Strongyloides

• Trichostrongyloidea Dictyocaulus

• Metastrongyloidea Filaroides Aleurostrongylus

• Filaroidea Microfilariae (blood)

Non-vermiform Larva 

Acanthocephala: (eggs contain an acanthor)

Cestodes: (onchosphere)

• Taeniidae (Taenia and Echinococcus)

• Hymenolepidae (Hymenolepis)

• Anaplocephalidae (pyriform apparatus) Moniezia Anoplocephala Paranoplocephala

• Dilepididae (egg packets) Dipylidium

• Thysanosomidae (Thysanosoma; egg packets)

Trematodes (operculated shell):

• Fasciola

• Paragonimus

Cestodes:

• Mesocestoididae:  (Mesocestoides)

Mite eggs (contain a larval mite)