Genus Plectus

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ORDER PLECTIDA
            Family Plectidae
                        Genus Plectus

 
Genus Plectus
Bastian, 1865
    Syn.  (Plectoides) de Man, 1904
             Pycnolaimus Cob, 1920
           Anaplectus de Coninck & Schuurmans Stekhoven, 1933


“Definition: Plectinae.  Cuticle with transverse striae and scattered fine bristles.  Lateral fields present.  Head more or less distinct and offset by the slight constriction.  6 lips; 4 cephalic setae just behind the level of the head.  Amphid openings, ring-like or elliptical.  Stoma, tubular and lined with rod-like rhabdions.  Oesophagus almost cylindrical, tapering slightly to the isthmus and ending in a muscular bulb containing a tri-radiate, denticulate valve apparatus.  Nerve ring crossing isthmus about madway of its length.  Excretory pore leading to a twisted excretory duct which joins a nucleated excretory cell lying ventral to the oesophagus.  (Bastian based the name Plectus on the twisted nature of the excretory duct.) Tail containing 3 caudal glands, which open at the tip through a terminal duct.  Female: Vulva equatorial, gonads paired, opposed and reflexed.  Male: Where known, with 2 testes, anterior and posterior, opening into a single vas deferens; spicules paired but asymmetriacl, gubernaculus complex.  A row of ventral tubular supplements sometimes present.  Pre-anal ventral setae may be present.
    Maggenti (1961) revising the genus recognizes Anaplectus as a separate one, but gives no reasons for this action.  De Coninck & Schuurmans Stekhoven (1933) erected Anaplectus for those species with 4 cephalic setae and tubular supplements on the male.  However, Plectus parietinus, the type of Plectus, has both characters.” From Goodey 1963 and Powers and Mullin website http://nematode.unl.edu/   

References:

Goodey T. and J.B. Goodey. 1963. Soil and Freshwater Nematodes.  Butler and Tanner Ltd, London, Great Britain

Powers T. and P. Mullin. Plant and Insect Parasitic Nematodes. University of Nebraska Nematology Website. http://nematode.unl.edu/