Manganonema		Contents		Rev: 10/12/2026
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Manganonema Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Xyalidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea

  Chromadoria

   Monhysterida

Monhysterina

Sphaerolaimoidea

                 Xyalidae

       Manganonema Bassau, 1993

Type species of the genus: Manganonema microcephalum Bassau, 1993

    Synonyms:
     

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Morphology and Anatomy:

Several of the species have been described from a single male specimen.

With general characteristics of family Xyalidae,

• Conspicuous narrow anterior end;  head diameter at least one third smaller than the body diameter at level of amphidial fovea, and marked or set off from the rest of the body by a narrowing region.
• Anterior sensilla arranged in two circlets: an anterior crown of six inner labial papillae, a second crown of six outer setiform labial sensilla and four cephalic sensilla (papilliform or setiform).
•  Stoma minute, surrounded by pharyngeal musculature.
• Amphideal fovea round, and relatively large (40-90% cbd).
• Tail pointed, curved dorsally upon fixation.
•  Body cuticle transversely striated; somatic setae short more or less papilliform and difficult tosee under light microscopy, arranged in four longitudinal rows (two latero- ventral and two latero-dorsal).
• No ventral gland of secretory-excretory system present. .

	Females: Monodelphic; anterior outstretched ovary to the left of the intestine. Vulva simple, located at mid-body. No differentiation of uterus, no spermatheca observed.        Ref: Fonseca et al. 2003
Manganonema media  Male a-d; a: total body; b: anterior; c: posterior; d: testis. Female e-h; e: total body; f: anteriof; g: prodelphic ovary; h: posterior. Drawings from Fonseca et al., 2006
Males:   Monorchic testis outstretched anteriorly on  left of the intestine Vas deferns long and narrow Spicules paired, straight; weak gubernaculum without apophysis.  Sperm cells small, globular, with a very dense nucleus
Body size range for the species of this genus in the database - Click:

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Distribution:

Free-living marine nematodes generally at depths > 600 m.  Worldwide distribution. Type species described from 4000m depth from the Eastern Pacific Basin off the coast of Peru (Venekey et al., 2014).

Usually found in low population densities; several of the species have been described from a single male specimen (Fonseca et al., 2003)..

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Feeding:

Food Sources and Feeding strategies for the genus Manganonema

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Biology and Ecology:

Manganonema is genus of deep-sea nematodes with greatest species diversity at depths >4,000 m. However, some species of the genus are also able to colonize  sediments at a water depth <1,000 m, where particular environmental conditions exist, for example the presence of strong near-bottom currents. The genus  appears adapted to habitats characterized by high hydrodynamic conditions which probably contributes to its wide distribution. (Zeppilli et al., 2011).

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Life Cycle:

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Ecosystem Functions and Services:

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Management:

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References:

Bussau, C. 1993. Taxonomische und Ekologische Untersuchungen an Nematoden des Peru-Beckens. PhD thesis, University of Kiel

Fonseca, G, Decraemer, W. Vanreusel, A. 2006. Taxonomy and species distribution of the genus Manganonema Bussau, 1993 (Nematoda: Monhysterida). Cah. Biol. Mar 47:189-203.

Venekey, V., Gheller, P.F., Maria , T.F., Brustolin, M.C., Kandratavicius , N., Vieira , D.C., Brito, S., Souza, G.S., Fonseca, G. 2014. The state of the art of Xyalidae (Nematoda, Monhysterida) with reference to the Brazilian records. Marine Biodiversity DOI 10.1007/s12526-014-0226-3

Zeppilli, D., Vanreusel, A., Danovaro, R. 2011. Cosmopolitanism and Biogeography of the Genus Manganonema (Nematoda: Monhysterida) in the Deep Sea. Animals 2011, 1, 291-305; doi:10.3390/ani1030291

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Revised by Howard Ferris.
Revised: October 12, 2026.