Haycocknema perplexum

Haycocknema perplexum	Contents	Rev: 09/23/2024
	Classification	Biology and Ecology
	Morphology and Anatomy	Life Cycle
Return to Haycocknema Menu	Economic Importance	Ecosystem Functions and Services
	Distribution	Management
Return to Robertdollfusidae Menu	Feeding	References
	Go to Nemaplex Main Menu	Go to Dictionary of Terminology

Classification:

Type species of the genus

    Synonyms:

Morphology and Anatomy:

Haycocknema differs from all other genera of the Muspiceoidea in having:

a large amorphous cellï¿½ supporting a granule-filled gourd-shaped reservoir in the rectal region of mature and gravid female nematodes
a pair of ampulla-shaped glands posteriorly

General characteristics:

Minute nematodes with simple cephalic end and sharply tapering caudal end.
Esophagus atrophied posteriorly; intestine transformed to trophosome, filled with dark, refringent granules.
Oral opening oval; cephalic papillae and amphids not observed.
Esophagus short, muscular with triradiate cuticular lining, constricting to narrow tube between large dorsal and two sub-ventral gland cells.
Esophagus atrophied posteriorly; intestine transformed into trophosome, fiï¿½lled with dark refringent granules, extending as fiï¿½ne thread to posterior region.
Dorsal gland and subventral glands narrowing to an isthmus anterior to nerve-ring then expanding in cephalic region around anterior esophagus and emptying at oral opening.
Ducts of glands most conspicuous in wholemounts of immature females and in histological sections, less conspicuous in males or mture females.
Muscles platymyarian, meromyarian,
Intestine replaced by a trophosome.
Tail tapering to bluntly-rounded tip.

Females:

Large amorphous cellï¿½ supporting a granule-filï¿½lled gourd-shaped reservoir in the rectal region of mature and gravid females nematodes
Immature females with lateral bacillary bands comprised of a single row of pore cells spaced irregularly and extending posteriorly to the region of the vulva
Didelphic, amphidelphic, vulva at mid-body, with small number of ova, eggs and larvae developing in each uterus
Some juveniles seem to emerge from ruptured cephalic region.

Ref: Spratt et al., 1999

Males:

Monorchic,
Spicule minute, weakly sclerotized, almost tubular.
Gubernaculum absent,
Cloaca raised

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

Distribution:

Described from Tasmania from a man in which muscle fibers of the vastus lateralis (one of the quadriceps muscles on the outside of the thigh) were irritated and inflamed (polymyositis).

Homo sapiens listed as type host of type species, H. perplexum (Spratt et al., 1999)

Feeding:

Adults and juveniles are parasites of the skeletal muscle fibers of humans.

Life Cycle:

Amphimictic reproduction (Spratt et al., 1999).

Ecophysiological Parameters:

For Ecophysiological Parameters for this species, click	If species level data are not available, click for genus level parameters

Ecosystem Functions and Services:

References:

Spratt, D.M 2013. Muspiceida. In Andreas Schmidt-Rhaesa (Ed) Nematoda

Spratt, D.M., Beveridge, I., Andrews, J.R.H., and Dennett, X. 1999. Haycocknema perplexum n.g. n.sp. (Nematoda: Robertdollfusidae) an intramyofibre parasite in man. Systematic Parasitology 43:123-131.