Tylenchorhynchus
Tylenchorhynchus Cobb, 1913 (ref. ID; 7200)
Family Tylenchorhynchinae (ref. ID; 5928)
Family Belonolaimidae (ref. ID; 6182)
ref. ID; 1923
With sclerotized cephalic framework; tails usually not acute. (A large genus, about 40 species, primarily terrestrial, occasionally aquatic) (ref. ID; 1923)
ref. ID; 6153
Herbivore. (ref. ID; 6153)
ref. ID; 6691, 6859
Plant parasite. (ref. ID; 6691, 6859)
- Tylenchorhynchus dubius (Butschli, 1873) (ref. ID; 2588) reported author and year? (ref. ID; 5914)
- Tylenchorhynchus maximus Allen, 1955 (ref. ID; 5928 original paper)
- Tylenchorhynchus robustus (De Man, 1876) (ref. ID; 3439)
Tylenchorhynchus dubius (Butschli, 1873) (ref. ID; 2588) reported author and year? (ref. ID; 5914)
Descriptions
Plant parasitic nematodes. (ref. ID; 5914)
Descriptions
Male: The male of a parthenogenetic plant-parasitic nematode. Body shape arcuate to nearly circular when heat relaxed, with near midbody 19-33 µm. Body annules variable in coarseness, but pattern consistent. Annules coarse immediately posterior to head (2.4 µm wide), abruptly narrowing to 1.2-1.4 µm at about one body width anterior to excretory pore. Annules on rest of body to anterior of bursa range from 1 to 2 µm wide. At the bursa the annules on ventral surface narrow to 1.0-0.5 µm wide, becoming usually less than 0.5 µm on tail similar to bursal annulation. Annules increase to 2.0-2.4 µm along dorsal surface at level of cloaca and stabilize to 2 µm on tail. Alternate striae on bursal margin terminate directly and are not continuous with the coarser transverse body striae. Lateral field with for incisures, originating as three within one body width posterior to stylet, increasing to four at midmetacorpal level and decreasing to one just posterior to cloacal opening. Outer incisures markedly crenate, regularly areolated; inner incisures irregularly areolated. Head high, apex rounded, marked by six to seven fine transverse annules. Width of head usually narrower than adjoining body and extending posterior to the septum of head skeleton. Subdorsal and subventral lips protuberant, lateral lips low, reduced. The exceptionally fine, acuminate stylet with small rounded basal bulbs sloping posteriorly is characteristic of this species. Orifice of dorsal esophageal gland 3-4 µm posterior to stylet knobs. Esophagus 161(150-173) µm long, length of metacorpus 16-19 µm, isthmus 40-50 µm, and basal bulb 20-26 µm. Nerve ring usually encircling anterior third of isthmus. Excretory pore 129(114-136) µm posterior to head end, ranging from a level near midisthmus to middle of basal bulb. Hemizonid zero to three annules anterior to excretory pore. Intestine containing fasciculi (lateral canals) typical of the genus. Testis single, outstretched, reproductive system 574(485-653) µm long, spermatogonia arranged in two rows. Spermatozoa spherical, small 0.70-1.0 µm in diameter. Cloacal opening covered by fold of cuticle. Spicule structure typical of genus, 32(30-34) µm long. Protrusible gubernaculum linear, 15-18 µm long, its distal end rectangularly thickened in lateral view, proximal end cephalated or hooked. Phasmids open on bursa slightly posterior to midtail. (ref. ID; 5928)
Dimorphic characteristics: There is no appreciable difference between males and females from the same populations in shape and size of the head, lips, stylet, and in their general body dimensions and proportions. Females are more extreme in body curvature than males, often becoming spiral when relaxed, and their body annules are more regular in size. By contrast with males, the annules of females are uniformaly coarse along the entire length of the esophagial region, becoming narrow only after one to two body widths posterior, and are usually uniform in size on all surfaces of the tail, being reduced only on the broadly rounded terminus. No spermatozoa were observed in the 12 females collected with these males. (ref. ID; 5928)
Measurements
Male: L=1.107(0.941-1.247) mm, a=44(37-52), b=6.9(6.0-7.4), c=19(17-21), c'=3.0(2.6-3.3), T=52(48-56). Stylet length 21(20-22) µm, M=52(50-56) (n=8). (ref. ID; 5928)