PHYLUM ACANTHOCEPHALA: Spinyheaded worms

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PHYLUM ACANTHOCEPHALA Spiny-headed worms --
most are gut parasites of fish, reptiles, birds
(sometimes mammals)
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Gut of duck
Gut of pig?
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PHYLUM ACANTHOCEPHALA Spiny-headed worms I.
General Anatomy -- pseudocoelmic -- no gut
body surface covered with pores
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PHYLUM ACANTHOCEPHALA Spiny-headed worms I.
General Anatomy A. Proboscis and lacunar
system
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PHYLUM ACANTHOCEPHALA Spiny-headed worms I.
General Anatomy B. Reproductive system
separates sexes (dieocious) 1. Male
testes
cement gland
copulatory bursa
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PHYLUM ACANTHOCEPHALA Spiny-headed worms I.
General Anatomy B. Reproductive system
separates sexes 2. Female
uterine bell
vagina
ovarian balls eggs
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PHYLUM ACANTHOCEPHALA Spiny-headed worms I.
General Anatomy C. Life Cycle -- eggs
pass with host feces -- hatches ? acanthor
larva
acanthor larva within egg
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PHYLUM ACANTHOCEPHALA Spiny-headed worms I.
General Anatomy C. Life Cycle -- infects
arthropod IH ? cystacanth (often alter behavior
appearance of IH) -- eaten by DH
cystacanths
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PHYLUM ACANTHOCEPHALA Spiny-headed worms
II. Taxonomy A. Neoechinorhynchus sp.
-- DH fish -- acanthor infects ostracod
(seed shrimp) ? cystacanth -- ostracod
ingested by fish
ostracod
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PHYLUM ACANTHOCEPHALA Spiny-headed worms
II. Taxonomy A. Macracanthorhynchus
sp. -- DH pig human (zoonosis) IH June
beetle grub adult beetle