Mehdinema

  

Contents

  

Rev: 08/24/2026

  Classification Biology and Ecology
Morphology and Anatomy Life Cycle
Return to Mehdinema Menu Ecosystem Functions and Services
Distribution Management
Return to Mehdinematidae Menu Feeding  References
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Classification:

Chromadorea
Chromadoria
Rhabditina
            Diplogastroidea
Mehdinematidae
        Mehdinema Farooqui, 1967

Type genus of the family,

  •  
    •   Type species of the genus: Mehdinema alii Farooqui, 1967
        Synonyms:
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    Morphology and Anatomy:

    Mehdinema alii (A) Adult male, entire specimen. (B) Adult female, entire specimen. (C) Female anterior end, lateral view. (D) Female stoma, lateral view. (E) Female vulva, lateral view. (F) Female tail, lateral view.

    Drawing from Luong et al., 1999

    		 Females:
    • Amphidelphic with reflexed ovaries.
    • Vulva at mid-body, with protruding lips with a knoblike projection on the anterior lip
    • Ovoviviparous,  both eggs and juveniles present in the uterus
    • Female tail is approximately 7.5-10 tx abr width at the anus, attenuates gradually to a furcated tip

    Ref : Luong et al., 1999
       

    		 

    Males:  

    • Shorter than female
    • Monorchic, testis ventral to intestine.  A cuticular flap is anterior to the cloacal opening
    •   1 pair of sublateral precloacal genital papillae located asymmetrically on either side of the body, 1 small mid ventral genital papilla located on the anterior cloacal lip, 2 pairs of postcloacal papillae that lie asymmetrically on either side of the protruding gubernaculum ;  3 dome-shaped caudal papillae arranged asymmetrically
    • Spicules paired, equal length, arcuate, needle-like, and apparently fused at the tip
    • Gubernaculum complex , an arcuate apophysis terminating in a ventrally directed, bifid cuticularized ptrocess.
    • Tail tightly coiled

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

    The host, cricket, Gryllodes sigillatus is distributed worldwide throughout the tropics. It has been recorded from Australia, Cuba, Mexico, and Florida., Southern California and Arizona, USA. The introduced tropical insect has adapted to more arid conditions.

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    Feeding:

    Food Sources and Feeding strategies for the genus Mehdinema

    Parasites of the hind gut of crickets, Gryllodes sigillatus

     
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    Biology and Ecology:

    The host cricket has a polygamous mating behavior in which male crickets attract females by through acoustic signals. Mating females receive a nutrient-rich spermatophylax, attached to a sperm-containing ampulla. The ampulla is removed after the spermatophylax is consumed. Females mate with multiple partners until enough sperm is obtained to fertilize available eggs

    Infection appears to be male-biased. 75% of adult male crickets were infected but only 13% of females. Infection intensity was greater in male than in female crickets.

    Most nematode infections in male crickets were in the hind gut with 25% in the genital chamber. Females had a low prevalence of nematodes in the hindgut but the majority of infected females had dauer juveniles (presumably the infective stage) in the genital chamber, suggesting sexual transmission..

    Thesex-biased infection may be a direct consequence of the sexual (Luong et al., 2000),  The transmission mechanism implies behavioral synchronization with the host; presumably resulting from a long coevolutionary relationship.

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    Life Cycle:

    Dauer juveniles are a survival and infectice stage. Juveniles are transmitted sexually from males to females (Luong et al., 2000)

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

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    Management:

     
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    References:

    Farooqui, M. N. 1967. On a new Mehdinematidae fam. nov. from Gryllus domesticus. Zoologischer Anzeiger 178: 322-326.

    Luong, L.T., Platzer, E.G., Zuk, M., Giblin-Davis, R.M. 2000. Venereal worms: sexually transmitted nematodes in the decorated cricket. J. Parasitology 86:471-477.

    Luong, L.T., Platzer, E.G., De Ley, P., Thomas, W.K. 1999. Morphological, molecular and biological characterization of Mehdinema alii (Nematode: Diplogasteriad) from the decorated cricket (Gryllodes sigillatus). J. Parasitol. 85:1053-1064.

     

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    Revisede by Howard Ferris.
    Revised: August 24, 2026.