Diastolaimus grossus

Diastolaimus grossus	Contents	Rev 02/21/2024
	Classification	Biology and Ecology
	Morphology and Anatomy	Life Cycle
Return to Diastolaimus menu		Ecosystem Functions and Services
	Distribution	Management
Return to Chambersiellidae menu	Feeding	References
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Classification:

      Chromadorea
       Rhabditida
         Rhabditia
          Chambersiellidae

Chambersiellinae

Diastolaimus grossus (Truskova & Eroshenko, 1977) Andrassy, 1984

Diastolaimus grossuswas originally described as Fescia grossa by Truskova & Eroshenko (1977) from Chuguyevsky district, Primorsky Krai (Far Eastern Siberia, Russia) . Genus Fescia was synonymized with Diastolaimus by Andrassy (1984) and Fescia grossus became Diastolaimus grossus (Truskova & Eroshenko, 1977) Andrassy, 1984.

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Morphology and Anatomy:

Moderately slender nematodes of small size, 0.94ï¿½1.38 mm long.
Body cylindrical, tapering towards both extremities, tail is conical.
Cuticle ca. 1 um thick, with very fine annuli, about 1um wide,
Lateral fields 2-4 um wide, consisting of two lines (three incisures) without transverse striation or areolation.
Lip region convex, continuous with body contour, with the oral region strongly elevated
Six curved, triangular liplets covering the oral aperture;
Anterior sensilla arranged in three circles: six thin seta-like inner labial sensilla located at base of each liplet, six elongate-conoid outer labial sensilla and four papilliform cephalic sensilla..
Amphidial apertures small, oval, labout. 15 annuli posteriorly to lips.
Stoma about as long as wide and about as long as lip region diameter, subdivided into cheilo-, gymno- and stegostom; stegostom one half of the cheilostom length, with shallow funnel-shaped lumen, enveloped by the anterior end of pharynx
Pharynx cephaloboid: corpus cylindrical, 1.3-1.6 times longer than isthmus, with procorpus and metacorpus similar in width; isthmus narrower.
Basal bulb nearly pyriform, with strongly developed valvular apparatus located at its posterior half. Cardia short and subcylindrical ..
Nerve ring at anterior half of isthmus. Secretoryï¿½excretory gland cell located ventrally to isthmus,
Deirids located posterior to nerve ring, inside the lateral field, close and posterior to excretory pore.

Female.

Didelphic-amphidelphic, both ovaries reflexed near to oviduct junction, very long, surpassing the level of the vulva.
Oviduct narrow and short with distinct narrowing spermatheca containing big spherical sperms.
Vagina straight, occupying one-third of body diameter. Vulva a transverse slit, with distinctly protruded lips that forms a vulval cone;
Tail conical, slightly ventrad curved, tapering very gradually and ending in a filiform forked terminus
Phasmids at 43-44% of tail length from anus.

Ref: Cermak et al., 2022

Male;

Monorchic, testis reflexed ventrad, on right-hand side of intestine. Spermatocytes first in two rows, then in only one row.
Spicules paired and symmetrical, 5.7-6.0 times longer than wide, curved ventrad with rounded manubrium, cylindrical calamus, ventrad curved lamina with reduced dorsal hump and a well-developed ventral velum.
Gubernaculum long, with thin manubrium and corpus with low central cuneus and well-developed triangular lateral crura.
Fourteen pairs of genital papillae; eight subventral precloacal pairs and six postcloacal pairs.
Tail conoid and tapering gradually and curved ventrad, ending in a short terminally forked filiform part.
Phasmids located in anterior half of tail, at 48% from anus.




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

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Distribution:

Originally described in 1977 from tree bark on branches of Abies sp. in Chuguyevsky district, Primorsky Krai (Far Eastern Siberia, Russia) . More recent collections (Cermak et al., 2022) Swere collected from bark from the bark from Namest na Hane, Czech Republic (Salix sp.) and from Banja Luka, Bosnia and Herzegovina (Pinus nigra ).

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Feeding:

Presumed bacterial feeders but maybe also feeding on other microbes and fungal spores.

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Biology and Ecology:

All the members of the subfamily Chambersiellinae are considered epiphytic nematodes that live on the bark of various tree species and can survive rapid and long dehydration (Cermak et al., 2022)

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Life Cycle:

Ecophysiological Parameters:

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

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Ecosystem Functions and Services:

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Management:

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References:

Andrassy, I. 1984. Klasse Nematoda. (Ordnungen Monhysterida, Desmoscolecida, Araeolaimida, Chromadorida, Rhabditida). Akademie Verlag, Berlin, 509 pp.

Cermak, V. Njezic, B., Foit, J., Kulich, P., Orsagova, H., Ruiz-Cuenca, A.N., Shokoohi, E., Abolafia, J. 2022. Redescription of Diastolaimus grossus (Truskova & Eroshenko, 1977) Andrï¿½ssy, 1984 (Rhabditida, Chambersiellidae) from Europe and comments on its phylogenetic position. Journal of Helminthology 96, e31, 1ï¿½14. https://doi.org/ 10.1017/S0022149X22000141

Truskova, G.M. & Eroshenko, A. 1977. Nematofaune vegetativnykh organov travjanistykh i drevesnykh rastenij elnikov primorja. Trudy Biologo-Pochvennogo Instituta 47:35-49.

Diastolaimus grossus

Copyright 1999 by Howard Ferris. Revised: February 21, 2024 .

Copyright 1999 by Howard Ferris.
Revised: February 21, 2024 .