Leptonemella, COBB, 1920

Armenteros, Maickel, Ruiz-Abierno, Alexei & Decraemer, Wilfrida, 2014, Taxonomy of Stilbonematinae (Nematoda: Desmodoridae): description of two new and three known species and phylogenetic relationships within the family, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 171 (1), pp. 1-21 : 9-10

LEPTONEMELLA COBB, 1920

Diagnosis (adapted from Tchesunov, 2013): Stilbonematinae . Cuticle with fine but distinct striation. Head capsule convex, surface smooth or punctuated, well KEY TO THE SPECIES OF THE GENUS LAXUS

1. Body length <4 mm ......................................................................................................................... 2 Body length> 4 mm ......................................................................................................................... 4

2. Tail> 2.0 a.b.d., spicule capitulum not marked ...................................................................... Laxus sigma Tail <2.0 a.b.d., spicule strongly cephalated ......................................................................................... 3

3. Spicule longer (> 1.5 a.b.d.), gubernaculum thick and curved ................................................. Laxus parvum Spicule shorter (<1.5 a.b.d.), gubernaculum thin ................................................................ Laxus gerlachi

4. Pharynx corpus enlarged (> 0.5 diameter of isthmus and> 0.3 pharynx length), de Man ratio a> 175 ............... ................................................................................................................................... Laxus oneistus Pharynx corpus different, de Man ratio a <175 .................................................................................... 5

5. Subcephalic setae about as long as the cephalic setae, gubernaculum thick ................................. Laxus cobbi Subcephalic setae shorter than cephalic setae, gubernaculum relatively thin ............................................. 6

6. Pharynx relatively longer (de Man ratio b <70), spicule relatively long (> 1.3 a.b.d.) ........... Laxus cosmopolitus Pharynx shorter (b> 70), spicule shorter (<1.3 a.b.d.) ............................................................ Laxus longus

demarcated from annulated body cuticle. Amphidial fovea latero-subterminal, small, spirally coiled in 1.5 turns, loop-shaped or formed as a shepherd’s crook, sausage-like corpus gelatum may be protruded. Pharynx very slightly swollen anteriorly. Gubernaculum without dorsocaudal apophysis. Males of some species equipped with stout postcervical, preanal, and postanal subventral setae. Tail elongateconical. Symbiotic bacteria coccoid to short stick-shaped.

We propose only two minor changes to the diagnosis by Tchesunov (2013): the deletion of (1) the presence of buccal cavity not developed as this is a diagnostic feature to subfamily level, and (2) the range of c′ values being 3–5 because the new species Leptonemella brevipharynx has c′ <3.

Type species: Leptonemella cincta Cobb, 1920 .

Valid species (seven): Leptonemella aphanothecae Gerlach, 1950 ; Le. brevipharynx sp. nov.; Leptonemella granulosa Boucher, 1975 ; Leptonemella gorgo Gerlach, 1950 ; Leptonemella juliae Hoschitz, Buchholz & Ott, 1999 ; Leptonemella vestari Hoschitz, Buchholz & Ott, 1999 ; Leptonemella vicina Riemann, Thiermann & Bock, 2003 .