Merlinius affinis
(Allen, 1955) Siddiqi, 1970
Syn.: Tylenchorhynchus affinis Allen, 1955
Nagelus affinis (Allen 1955) Siddiqi, 1979
Photo Gallery- allotype and paratype


Dimensions.- 6 females  L = 0.8 - 0.9 mm  a = 30 - 33  b = 4.2 - 5.0  c = 14 - 15  V = 55 - 58  Stylet 26 - 27 u long
Female (holotype).  L =  0.86 mm  a = 33  b = 4.7  c = 15  V = 55
Body cylindrical, tapering at both ends.  Lip region conoid-obtuse, continuous with body contour, bearing 8 annules.  Labial framework heavily sclerotized.  Stylet massive, 27 u long, with large rounded knobs.  Orifice of dorsal esophageal gland 2.5 u behind spear base.  Excretory pore opens just behind nerve ring.  Spermatheca containing spermatozoa present.  Tail subcylindrical, with terminus bluntly rounded, not annulated.  Cuticle coarsely striated.  Lateral field with 6 incisures.  Phasmids prominent, opening at middle of tail.
Male (allotype). L = 0.96 mm  a = 34  b = 5.2  c = 12  Stylet 25.6 u long.
Similar to female.  Bursa envelops tail.  Spicules tylenchoid.  Gubernaculum simple, curved.
Type host.  Soil around roots of Arctostaphylos sp.
Type locality.  Willets, California.

Tylenchorhynchus affinis can be distinguished by the six incisures in the lateral field, the continuous lip region, and the heavily sclerotized labial framework.  This species can be separated from brachycephalus by the shape of the tail and the length of the spear.  It differs from brevidens in having a longer spear and heavier labial sclerotization.
(Description- Allen, 1955)