Lobocriconema thornei
Knobloch & Bird, 1978
Photo Gallery- 9 Mile Prairie
Photo Gallery- Homestead Nat'l Monument Prairie
Photo Gallery- Plattsmouth, NE

The undescribed species of the genus Lobocriconema, recovered commonly and in high population densities from the original sampling of the experimental site, was named Lobocriconema thornei in honor of Professor Gerald Thorne.  His guidance, encouragement, and friendship will never be forgotten.  The morphometrics and morphological descriptions of the types are:
    Holotype female:  L = 0.50; a = 9.4; b = 3.6; V = 90%; stylet 87 um; R (number of body annules) 46.
    Paratype females: (20): L = 0.55 (0.48 - 0.64) mm; a = 9 (8 - 11); B = 3.8 (3.2 - 4.5); c = (from ventral view of two paratype females) 37 - 38; V = 92% (90 - 92%); stylet = 89 (85 - 97) um; R = 49 (46 - 51).
    Body thick, cylindroid, tapering toward both blunt extremities.  Body straight or very slightly ventrally arcuate when killed by gentle heat.  Annules retrorse except two most-anterior; posterior edges smooth.  In a few paratype females, posterior edges rough on ventral side near posterior end.  Very faint ornamentation of small lines, dots, or punctations on subcuticle underneath each annule.  Width of annules at mid-body about 10 um, no anastomoses.  Stylet well developed; basal part 22 um long; anterior part 67 um long.  Basal knobs about 12 um wide with pointed outer edges directed anteriad.  Submedian lobes and cephalic framework prominent.  Excretory pore opening in fifteenth annule from anterior end.  Vulva on fifth annule from terminal knob.  Vagina sigmoid, narrow, leading to a wide uterus; round spermatheca prominent, filled with sperm.  Ovary prodelphic, outstretched.  In a few specimens, ovary is reflexed; in some specimens, ovary extends to middle of stylet.  Anus not observed in holotype; in ventral views of paratype females, anus on first or second annule from terminus.  Tail conoid, bluntly rounded at end, with knob at terminus.
    Allotype male:  L = 0.56 mm; a = 20; c = 11; spicules = 47 um; gubernaculum = 8 um; T = 33.
    Paratype males (2): L = 0.49 (0.48 - 0.50) mm; a = 20 (19 - 21); c = 10 (10 - 11); spicules 45 (44 - 46) um; gubernaculum 7.5 (7 - 8) um; T = 39 (38 - 41).
    Body almost straight in anterior part; at middle of body, shape becomes ventrally arcuate.  Head flatly rounded.  Annulation coarse.  Lateral field with four incisures.  Excretory pore opening on 30th body annule from anterior end.  Hemizonid located at third annule anterior to excretory pore.  Testes single, occupying most of body width.  Spicules 47 um long, slender, curved cephalate proximally, pointed distally.  Anal sheath present.  Gubernaculum slightly curved, 8 um long.  Tail curved ventrally, rounded at terminus. Bursa as illustrated.
    Juvenile: 3rd stage: L = 0.32 mm; a = 11; b = 3.3; stylet = 54 um; R = 53.
    No juveniles of L. thornei were found for several years.  On April 26, 1976, several fourth-stage moults with the adult female and male were collected at the original site.  Later a third moult was found and a third-stage nonmoulting juvenile. The fouth-stage juvenile is 0.29 mm, with 51-52 body annules and stylet 65 um long. Cuticular patterns are as shown.
    DiagnosisLobocriconema thornei is most similar to L. neoaxestum (Jairajpuri & A. H. Siddiqi, 1963) de Grisse, 1967, L. crassianulatum (de Guiran, 1963) de Grisse & Loof, 1965, and L. rara Boonduang, A. and R. Ratanaprapa, D., 1974. L. thornei differs from L. neoaxestum in shape of head region, length of stylet, smooth body annules, position of vulva. L. neoaxestum has a poorly differentiated neck annule, stylet 65-75 um long, body annules marked with longitudinal striations and rough posterior margins, vulva on seventh or eighth annule, and juveniles present.  From L. crassianulatum, L. thornei differs in its larger size, number of body annules, stylet length, shape of head, and tail terminus. L. crassianulatum has a body length of 236 - 362 um, 33 - 41 body annules, stylet length 51 - 70 um; and although the neck annule is well differentiated, all the body annules except the first are retrorse and the tail terminus is ventrally contracted.  From L. rara, it differs in body length, vulval position, stylet length, and number of body annules.  L. rara has a body length of 0.375 (0.350 - 0.400) mm; V = 95.9 (94.3 - 97.5)%; stylet 54 (51 - 57) um; and body annules 61 (56 - 65).
    Type habitat and locality:  Soil around roots of maple trees, Acer saccharum, and numerous other habitats in woods of the Michigan State University Water Quality Management Project site in East Lansing, Michigan, U.S.A.
(Description- Knobloch & Bird, 1978)

This species included in the Criconematid Project

DNA Sequences Obtained:
Specimen:                                 Collected:
9miLP-01 9 Mile Prairie
HomeLPR-54 Homestead Nat'l Monument
HomeLPR-17 Homestead Nat'l Monument
Platts-04-juv Plattsmouth, NE
Platts-04-fem Plattsmouth, NE