Phylum nematomorpha

Complete Details of Phylum Nematomorpha

1. Phylum Nematomorpha

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

4. Life Cycle of Nematomorpha

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. 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. Life Cycle of Nematomorpha

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

10. Are the only known marine nematomorph , parazitize crustaceans. Very rarely seen Class Nectomatoda Nectonema zealandica

11. Consist of the rest freshwater and semi- terrestial species. Parasitize insects. Class Gordioda Gordius robustus