Gammanema

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

Chromadorea
Chromadoria
Chromadorida
Selachinematidae: Choniolaiminae
Gammanema Cobb, 1920

Type species of the genus: Gammanema uniformis (Cobb, 1920) Tchesunov & Okhlopkov, 2006

Synonyms:
Trogolaimus uniformis Cobb, 1920

Morphology and Anatomy:

Body cylindrical, slender
Cuticle transversely striated and evenly punctate, punctations densely arranged in transverse rows;
Cephalic cuticle thickened, sclerotised and refractive
Mouth opening surrounded by six flat lips. Head sensilla arranged in two circles 6+10. Anterior circle represented by six inner labial papillae.
Amphidial fovea spirally coiled in four turns in males and three turns in females, located at level of posterior stoma chamber.
All somatic setae (except cephalic) inserted in crater-like cuticular pores. Short somatic setae and cuticular pores with minute sensilla sparsely distributed along body.
Buccal cavity with two heavily cuticularised chambers. Anterior chamber large and cup-shaped, with walls reinforced by 12 dense rhabdions. Twelve transparent non-sclerotised rugae bulging into lumen of anterior stoma chamber. Posterior chamber a narrow, inverted pyramid; walls armoured with three rhabdions, rhabdions less cuticularised than those anteriorly.
Pharynx widened around stoma, cylindroid further posterior, slightly thickening towards its base.
Nerve ring located ca in middle of pharynx.
Tail short and bluntly conical. Caudal glands with voluminous ampoules distally occupying most of internal space of tail. Terminal spinneret short, conical, nipple-like.

Females:

Didelphic, amphidelphic, ovaries antidromously reflexed.
Spermatheca present

Ref: Tchesunov and Okhlopkov, 2006; Huang and Guo, 2022

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

Males:

Diorchic with opposed testes,
Pre-cloacal, ventromedian supplementas 19-22. Each supplement cup-shaped or sucker-shaped,
Minute midventral spine 2 um long present just anterior to cloaca.
Spicules large, strong, slightly arcuate, distally acute and proximally with ventrally or laterally bent knobs.
Gubernaculum slightly arcuate and nearly parallel to spicules. .
Lateroventral series of four to six conical papillae 1-2 um long on either side of tail.

Distribution:

Predatory marine nematodes. Specimens described from Kennebunk, Maine, USA. Reported from intertidal sandy sediment

Feeding:

Food Sources and Feeding strategies for the genus Gammanema

Predators

Life Cycle:

For Ecophysiological Parameters for this genus, click

Ecosystem Functions and Services:

Predator.

References:

Cobb, N.A. 1920. One hundred new nemas. (Type species of 100 new genera). Contributions to a Science of Nematology (Baltimore) 9, 217-343

Huang, Y. and Guo, Y. 2022. Free-living Marine Nematodes from the East China Sea. Springer, Singapore and Science Press, Beijing.

Tchesunov, A.V. and Okhlopkov, J.R. 2006. On some selachinematid nematodes (Chromadorida: Selachinematidae) deposited in the collection of the Smithsonian National Museum of Natural History. Nematology 8:21-24.

Gammanema

Contents

Classification:

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Morphology and Anatomy:

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Distribution:

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Feeding:

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Biology and Ecology:

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Life Cycle:

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Ecosystem Functions and Services:

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Management:

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References:

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Revised by Howard Ferris.
Revised: August 24, 2026

Gammanema

Revised by Howard Ferris. Revised: August 24, 2026

Revised by Howard Ferris.
Revised: August 24, 2026