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Invertebrate
Zoology Kingdom: Animalia, Phylum: Nematomorpha (Contact)
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underlined file names and included illustrations to enlarge: The Nematomorpha
were previously known as the Gordiacea. They appear as Nematoda superficially,
although internally they are considerably different. They do not have a lateral line or an
excretory canal. Their nervous system
consists of a dorsal brain and a single ventral cord. The genital ducts of both sexes open into
the hindgut to form a cloaca.
Development is unique with gastrulation
by invagination and the larvae have a
peculiar boring organ that infects
insects. Their alimentary canal is
usually degenerate and the body cavity may either contain parenchymous tissue
or mostly empty of cells. Borradaile & Potts (1958)
discussed an example of he phylum, Gordius robustus. Adults of this species occur in streams
during late autumn until late spring when they copulate. The sperm is not introduced directly into
the cloaca, but rather is
placed in masses on the body nearby.
The eggs are laid in the water and the larvae hatch. They have a boring organ that allows them to
find their way into the body cavity of crickets living nearby in the
water. There they remain and grow
until autumn when they leave their host and enter the water again as mature
organisms.
------------------------------------ Please see
following plate for Example Structures of the Nematomorpha: Plate 64 = Phylum: Nematomorpha -- Trichinella sp. = Gordian worms ============== |
