2. Defining Characteristic
Body cylindrical, bluntly rounded at ends
No segmentation
Bilateral symmetry
Pseudoceol open (Nectonema) or nearly filled
with mesenchyme (Gordioidea)
Sexes separated (Dioecious)
Digestive tract degenerate, young worms
absorb food from host, adult non feeding
Live in fresh water such pond and lakes
3. Mating and Reproduction
Females are normally
sedentary and are
searched for by the more
active males who curl
themselves around the
females and deposit a
spermatophore near the
females cloaca
5. Life Cycle of Nematomorpha
1. Eggs
Adults mate in aquatic
environments and a single
female may lay as many as 10
million eggs
6. Life Cycle of Nematomorpha
2. Larvae
Eggs will develop into
larvae within about 2-4
weeks. These larvae
will hatch, and move
about the water in
slow, creeping motions.
7. Life Cycle of Nematomorpha
3. Cyst Stage
Larvae are heavy, cannot
swim and will stay at the
bottom of the water
column, and will thus look
for hosts in the bottom of
rivers and streams. The
larvae will now have to find
a way to get into the body of
the cricket.
These cysts are extremely
resistant and can stay alive
within the transport host for
at least one year.
8.
So how do cysts get into crickets? They likely use
aquatic insects. Aquatic insects, as larvae look
like small "worms" and live under
water. However, when they metamorphose they
turn into the flying insects, which we are used to
seeing. This also means that the cysts formed
within these insects can be carried from the water
(in the insect larvae) to the land (in the insect
flies). The flies can then carry these cysts to
where the crickets live. Many studies have shown
that crickets are omnivores- this means they eat
anything and up to one-third of what they eat is
dead insects
9. Life Cycle of Nematomorpha
4. Adult Stage
As a final act, worms
manipulate the
behavior of the
cricket, and it commits
'suicide