Laxus

 

Contents

  

Rev: 01/16/2023

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

Chromadorea
  Chromadoria
   Desmodorida
Desmodorina
             Deamodoroidea
                Desmodoridae
       Stilbonematinae

  •         Laxus Cobb, 1894
    •      

        Synonyms:
         

    Type species:  Laxus longus Cobb, 1894

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    Morphology and Anatomy:

     

    • Head capsule with thickened cuticle that has a basal layer with "building block" configuration.

    • Six inner labial sensilla and six outer labial sensilla thgat are setiform papillae. Four cephalic sensilla setiform. Four short subcephalic setae very close to the cephalic setae and another four short sublateral setae.

    • Amphid fovea spiral shape.

    Females:

    • Didelphic, ovaries antidromously reflexed, both genital branches to the left of intestine.

     
     


    Males:      

    • Monorchic, anterior testis to the left of the intestine.

    •  Spicules paired and curved, capitulum present;

    • Gubernaculum abroad and curved

    • No supplements.

    •  

     

    Ref: Armenteros et al., 2014

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

    Marine nematodes in tidal sands and coral reefs.

     
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    Feeding:

    Nematodes in the subfamily Stilbonematinae of the Desmodoridae are associated with, and feed on,  dense coatings of sulfur-oxidizing chemoautotrophic gammaproteobacteria with which they are apparently obligately symbiotic. The nematodes inhabit environments with low oxygen availability and reducing conditions. Essentially, the nematodes farm their bacterial associates by migrating to ocean sediments rich in hydrogen sulfide (Bulgheresi Reference Bulgheresi2011; Blaxter and Koutsovoulos, 2015;.Murfin et al. Reference Murfin, Dillman, Foster, Bulgheresi, Slatko, Sternberg and Goodrich-Blair2012;)

     

     

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    Biology and Ecology:

     

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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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    Management:

     
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    References:

    Armenteros, M., Ruiz-Abierno, A., Decraemer, W. 2014. Taxonomy of Stilbonematinae (Nematoda: Desmodoridae): description of two new and three known species and phylogenetic relationships within the family. Zool; J. of the Linnean Soc. 171:1-21.

    Blaxter, M. and Koutsovoulos, G. 2015. The evolution of parasitism in Nematoda. Parasitology 142: S26-S39.

    Bulgheresi, S. 2011. Calling the roll on Laxus oneistus immune defense molecules. Symbiosis 55:127-135.

    Chitwood, B.G. 1936. Some marine nematodes from North Carolina. Proc. Helmint. Soc. Wash. 3: 1-16.

    Murfin, K. E., Dillman, A. R., Foster, J. M., Bulgheresi, S., Slatko, B. E., Sternberg, P. W. and Goodrich-Blair, H. 2012. Nematode-bacterium symbioses - cooperation and conflict revealed in the Omics� age. Biological Bulletin 223: 85-102.

     

     
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    Copyright © 1999 by Howard Ferris.
    Revised: January 16, 2023.