The Phylum Nematomorpha

NematomorphaEtymology: from the Greek word

“Nema” for thread

“Morphe” for shape

or form

GENERAL DESCRIPTION

They are called Horsehair Worms, because they used to be found in horse watering troughs and they look like the hairs from a horses tail.

typically tan to black in color

GENERAL DESCRIPTIONThey are long thin worms (1 to 3

mm diameter and 3 ft in length)

bilaterally symmetrical, and vermiform

GENERAL DESCRIPTION

Body possesses in a cuticle and longitudinal muscles.

Has an intra-epidermal nervous system with an anterior nerve ring. 

GENERAL DESCRIPTION

has no circulatory, respiratory and excretory systems

Its body possesses a through gut which is normally non-functional.

Nematomorphan larvae are parasitic, eating and absorbing their hosts’ body tissues in early stages.

MODE OF NUTRITION

They are parasites of invertebrates, though not necessarily aquatic ones.

MODE OF NUTRITION

Feeding on nutrients from the bodily fluids.

The larvae have a better developed digestive system than the adults.

Nematomorphans are dioecious and reproduce sexually

REPRODUCTION

Males have one or two testes which open to cloaca via sperm duct

REPRODUCTION Females may have pair of elongated

ovaries, which open to the cloaca via semina receptacle

A female may lay millions of eggs during breeding seasons.

Longitudinal muscles (no circular) underlie cuticle. Move with characteristic s-shaped movements.

LOCOMOTION

HABITATNematomorphans are found in

aquatic or occasionally terrestrial Either aquatic individuals themselves or within terrestrial host

Habitat regions: Saltwater or marine Freshwater

CLASSIFICATIONClass Nectonematoidea

species are marine floating worms

are found in coastal, marine, and open sea environments as adults

are found as parasites in decapod crustaceans as larva

a dorsal and ventral nerve cords

CLASSIFICATIONClass Nectonematoidea

Cuticle possesses swimming bristles

They are known from the waters of Indonesia, Japan, New Zealand, the Northern Atlantic, and the Mediterranean.

parasitize marine invertebrates

Single reproductive gland (as an ovary or testes) that produces gametes only.

CLASSIFICATIONClass Gordioida

A dorsal and ventral nerve cords. Generally called hair worms.

Only a ventral nerve cord.

Are found in freshwater, most commonly along the banks of ponds and streams, and some are semi-aquatic and live in damp soil.

CLASSIFICATIONClass Gordioida

They are known from every continent, with the exception of Antarctica. The most common host are grasshoppers, crickets, and some beetles and cockroaches. However, some are found in humans, livestock, and pets.

They utilize terrestrial arthropods and are free-living and aquatic as adults.