Rev: 07/18/2022

  Classification Biology and Ecology
Morphology and Anatomy Life Cycle
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Distribution Management
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        Chronogaster Cobb, 1913
   The type and only genus of the family Chronogastridae Gagarin, 1975 


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Morphology and Anatomy:


"Stirrup-shaped" amphid.

Drawing from University of Nebraska

  • Four cephalic setae.

  • Oval or uni-spiral amphids.

  • Stoma elongate, tubular or funnel-shaped, no teeth.

  • Cuticle striated, sometimes with longitudinal ridges and spines

  • Esophagus with terminal bulb that has an elongate, multi-chamber valve and long extension so that the bulb may appear to be median rather than terminal.

  • Females monovarial, prodelphic.

  • Male with supplements

  • No spinneret or caudal glands in tail.

The family name literally translates as clock-stomach.  Andrássy (2005) speculates that Cobb provided the name to the genus Chronogaster because the elongate valve in the terminal bulb resembles the hands of a clock.  Alternatively, the esophagus with terminal bulb and its elongate extension might be considered to resemble the pendulum of a clock.

Body size range for the species of this genus in the database - Click:
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Primarily freshwater nematodes; also in thermal springs, mosit soils, algal and fungal mats (Abebe et al., 2013)..

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Biology and Ecology:

Species of the genus are reported to have great physiological plasticity and tolerance to high level of oxygen fluctuation; besides freshwater, they occupy salty habitats including caves (Abebe et al., 2006; Abebe et al., 2013; Hodda et al., 2006).

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Life Cycle:

For Ecophysiological Parameters for this genus, click 
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Ecosystem Functions and Services:

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Abebe, E., Ferebee, B., Taylor, T., Mundo-Ocampo, M., Mekete, T., De Ley, P. 2013. Neotobrilus nicsmolae n. sp. (Tobrilidae: Nematoda) and Chronogaster carolinensis n. sp. (Chronogasteridae: Nematoda) from Lake Phelps, North Carolina. J. Nematology 45: 66-77.

Abebe E., Traunspurger W., Andra�ssy I., eds. 2006. Freshwater nematodes: ecology and taxonomy. Wallingford, UK; CAB International.

Andrássy, I. 2005. Free-living Nematodes of Hungary Vol 1.  Hungarian Natural History Museum, Budapest.

Hodda, M., Ocana, A., and Traunspurger, W. 2006. Nematodes from extreme freshwater habitats. Pp. 179�210 in E. Abebe, W. Traunspurger, and I. Andra�ssy, ed. Freshwater nematodes: Ecology and taxonomy. Wallingford, UK: CAB International.

Copyright © 1999 by Howard Ferris.
Revised: July 18, 2022.