Glochinema bathyperuvensis		Contents		Rev 04/04/2023
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Glochinema Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Epsilonematidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea

  Chromadoria

   Desmodorida

Desmodorina

             Desmodoroidea

              Epsilonematidae

 Glochinematinae

    Glochinema bathyperuvensis Neira, Gad, Arroyo & Decraemer, 2001

 

Morphology and Anatomy:

Glochinema bathyperuvensis !A: Male whole body; 1B Female mid-body, arrow showing position of vulva. from Neira et al., 2001

• Body large, epsilon-shaped, anterior region very elongated and slender to ventral bend with sharp concave-dorsal curvature at the anterior cervical region and, mid-body ventrally plicated.
•  Thick body cuticle distinctly annulated; annules overlapped by a well-developed hyaline outer-layer, changing in direction ventrally at level of annules 93- 108.
• Anteriormost annules devoided of hairy spines. From annule 13 onward, annules ornamented with faint transversal ridges and hairy spines.
•  Immediately posterior to the base of the pharynx, 7-8 anteriorly oriented thorns, located ventrally between annules 48 and 59, coinciding with the minimum body width (20 um).
• Posterior to the ventral thorns, a series of thick small spines protrudes forwards from the ventral side.
• Nine large paired subdorsal thorns arranged asymmetrically and a single dorsal thorn present in the neck region; posteriormost dorsal thorn strong.Thorns with a more pronounced inclination towards the body closer to cephalic region, some of them accompanied by somatic setae.
• A subventral series of 10-13 single blade-like cuticular protrusions forming a latero-dorsal palisade surrounding the cervical region,
• .Ambulatory setae arranged in 4 rows: two inner subventral rows with 8-9 straight slender setae, and two outer subventral rows with 9 long, curved (not knicked) ambulatory setae, followed by a row of 29 straight supporting setae with pointed at tip.
• Head rounded with a strongly cuticularized helmet 1.5x narrower than the body diameter at base of pharynx.
• Amphids spiral, ventrally wound, medium sized (667 um), located in posterior head region; head on both sides with an indentation anterior to the amphideal fovea.
•  Anterior sensorial organs with six inner labial papillae, six short, outer labial setae and four cephalic setae at the level of the anterior border of the amphids.
• Buccal cavity narrow, with one dorsal denticle.
• Pharynx swollen in cephalic region, then long cylindrical, gradually enlarging to an elongated bulb with sclerotized lumen wall; cardia short, rounded. Intestine largely dorsal of reproductive system.
•  Tail with 18 annules and conico-cylindrical, ending in a small spinneret.
•  Caudal glands extending far anteriorly beyond the cloacal opening. Reproductive system, monorchic with outstretched testis reaching the anterior ventral curvature; large sperm cells; vas deferens with small granules. Spicules paired, slender, sickle-shaped, with a knob-like capitulum (Figs. 1A; 3C). Gubernaculum thin, 25% of the spicule length (measured along arc). A row of about 10 anal setae present on each side of the cloacal region. Annules in cloacal region ventrally to subventrally with few hairy spines (Fig. 4F). Dorsally, spines stiffened and together arranged comb-like. Some of them bifurcated at the tip.

Male:

• Noticeable enlargement of body at testis level reaching its maximum body diameter (110 µm
• Monorchic, testis outstretched and reaching the anterior ventral curvature.
• Large sperm cells; vas deferens with small granules.
• Spicules paired, slender, sickle-shaped, with a knob-like capitulum.
•  Gubernaculum thin, 25% of the spicule length.
•  A row of about 10 anal setae present on each side of the cloacal region.

Female

• Didelphic-amphidelphic, with reflexed ovaries.
• Vulva situated ventrally at 60% of the total body length from anterior end. Area surrounding the vulva devoid of ornamentation.
• Vagina with short sclerotized distal part and larger (11 um) but less sclerotized proximal part.

Ref: Neira et al., 2001

Back to Top

Distribution:

Back to Top

Feeding:

Back to Top

Biology and Ecology:

Conditions in the core of oceanic OMZs include hypoxia and occasionally anoxia, high sulphide concentrations and other limiting physical conditions, but abundant food availability.

Nematodes are considered more tolerant of hypoxia and even anoxia than other marine meiofauna. Increase of body surface area through cuticular and thorn-like ornamentation are proposed as features that reduce rate of sinking inot anoxic sediment and to perhaps increasae surface area for oxygen uptake (Neira et al., 2001).

Back to Top

Life Cycle:

Ecophysiological Parameters:

Back to Top

Ecosystem Functions and Services:

Back to Top

Management:

Back to Top

References:

Back to Top

Copyright © 1999 by Howard Ferris.
Revised: April 04, 2023.