Tokorhabditis		Contents		Rev 06/30/2023
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Tokorhabditis Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Rhabditidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea

  Rhabditia

    Rhabditida

      Rhabditoidea

        Rhabditidae

    Type species of the genus: Tokorhabditis tufae Ragsdale, Kanzaki, Yamashita & Shinya 2022

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Morphology and Anatomy:

• Adult lips not offsetfrom body contour
• Mouth opening triangular.
• Metarhabdions each bearing two denticles,
• Pharyngeal sleeve, median bulb, one excretory-secretory cell, males(Characters in bold are apomorphies.)

Females:and Hermaphrodites:

•  Female and hermaphrodite tail elongate conoid tapering, morphologically not distinguishable.
• Embryonic growth in utero; eggs hatch in utero;
• Both females and hermaphrodites ore obligately viviparous with juveniles deriving nutrition from their mother.

Males:

•  Much smaller than females and hermaphrodites.
• Open leptoderan bursa with a spike.
• Eight pairs of genital papillae (GPs), 3 or 4 pairs precloacal, GP1 anterior to spicules, GP5 and GP7 point dorsally, GP6 separate, phasmid pore anterior GP7.
• Testis length only about half intestine length with short ventral flexure,
• Gubernaculum nearly half of spiculum length.

Ref: Sudhaus, 2023

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Distribution:

All species so far associated with dung beetles.

Type species, T. tufae, reported from soil at the edge of Mono lake, California, USA, associated with dung beetles as a carrier. Mono Lake is an extremely inhospitable environment; alkaline, hypersaline, and arsenic-rich (Sudhaus, 2023).

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Feeding:

  Bacterial feeders. 

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Biology and Ecology:

Apparently in phoretic relationships with dung beetles.

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Life Cycle:

Tokorhabditis spp. are cosidered by Kanzaki et al (2021) to be  useful model system for studying the biology and adaptations of life in extreme environments.

• Trioecious mating system comprising males, females and self-fertilising hermaphrodites.
• Dauer juveniles develop into hermaphrodites,

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Ecosystem Functions and Services:

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Management:

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References:

Kanzaki, N., T. Yamashita, J. S. Lee, P.‐Y. Shih, E. J. Ragsdale and R. Shinya (2021): Tokorhabditis n. gen. (Rhabditida, Rhabditidae), a comparative nematode model for extremophilic living. – Scientific Reports 11: 16470

Ragsdale, E. J., N. Kanzaki, T. Yamashita and R. Shinya 2022: Tokorhabditis tauri n. sp. and T. atripennis n. sp. (Rhabditida: Rhabditidae), isolated from Onthophagus dung beetles (Coleoptera: Scarabaeidae) from the Eastern USA and Japan. – Journal of Nematology 54: e2022-1, 1-20.

Sudhaus, W. 2023. An update of the catalogue of paraphyletic Rhabditidae (Nematoda) after eleven years. Soil Organisms 95: 95-116

Yeates, G.W., T. Bongers, R. G. M. De Goede, D. W. Freckman, and S. S. Georgieva. 1993. Feeding habits in soil nematode families and genera—An outline for soil ecologists. Journal of Nematology 25:315-331

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Copyright © 1999 by Howard Ferris.
Revised: June 30, 2023.

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