Paracyatholaimus

Paracyatholaimus	Contents	Rev: 08/24/2026
	Classification	Biology and Ecology
	Morphology and Anatomy	Life Cycle
Return to Paracyatholaimus Menu		Ecosystem Functions and Services
	Distribution	Management
Return to Cyatholaimidae Menu	Feeding	References
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Classification:

Chromadorea
Chromadoria
Chromadorida: Chromadorina
Chromadoroidea
Cyatholaimidae: Paracanthonchinae
Paracyatholaimus Micoletzky, 1922

Type species of the genus: Paracyatholaimus dubiosus (Butschli, 1874) Micoletzky, 1922

Synonyms:

Morphology and Anatomy:

cylindrical body with conical tail;
cuticle punctated, lateral differentiation difficult to discern or absent
buccal cavity with cheilostom with 12 supportive rugae; stoma shallow, cup-shaped, with large dorsal tooth and two small subventral teeth
amphids multispiral
pharynx cylindrical, slightly widening posteriorly but without basal bulb, esophago-intestinal valve prominent
coarse punctations of cuticle
tail conical with scattered setae, becoming slender with a terminal spinneret

Females:

Didelphic-amphidelphic

Ref: Vincx et al., 1982; Huang and Xu, 2013; Cunha, 2023; Tchseunov, 2013

Paracyatholaimus qingdaoensis A:Female lateral view; B: Male pharynx region; C: Male posterior
Drawings from Huang and Xu, 2013

Males:

ventromedian supplements setiform
diorchic
gubernaculum dilated distally, truncate or notched but not dentated.

Body size range for the species of this genus in the database - Click:

Distribution:

Free-living marine nematodes, generally considered indicators of high organic content. Often from muddy sediments.

Mainly marine but some species reported from brackish and freshwater.

Feeding:

Food Sources and Feeding strategies for the genus Paracyatholaimus

Microbes; epistrate feeders

Life Cycle:

For Ecophysiological Parameters for this genus, click

Ecosystem Functions and Services:

References:

Bongers, T. 1994. De Nematoden van Nederland.

Coomans, A., Vincx, M., Decraemer, W. 1985. Nematodes from a fresh-water pool on a coral island in the Solomon Islands. Hydrobiologia 123:265-281.

Cunha, B.R. 2023. Diversity of Free-living Marine nematodes: Taxonomy and Syatematic of Family Cyatholaimidae. PhD Thesis, University of Campinas, Brazil

Goodey, T and J.B. Goodey, 1963. Soil and Freshwater Nematodes. Methuen. London

Huang, Y., Xu, K. 2013. Two new species of the genus Paracyatholaimus Micoletzky (Nematoda:Cyatholaimidae) from the Yellow Sea. J. Natural History 47:1381-1392.

Tchesunov, A.V. 2013. 7.12 Order Chromadorida Chitwood, 1933. In Schmidt-Rheas and de Gruyter, W. Handbook of Zoology.Gastrocticha, Cycloneuralia, Gnatifera. Volume 2: Nematoda

Vincx, M., Sharma, J., Smol, N. 1982. On the Identity and Nomenclature of Paracanthonchus caecus (Bastian, 1865), with a Redefinition of the Genus Paracanthonchus Micoletzky (Nematoda, Cyatholaimidae). Zoologica Scripta, 11: 243-263.