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Table 5 Comparative morphometrics of first-stage larvae (DSL) of Varestrongylus and of Elaphostrongylinae sympatric with V. alces

From: Resurrection and redescription of Varestrongylus alces (Nematoda: Protostrongylidae), a lungworm of the Eurasian moose (Alces alces), with report on associated pathology

Characters V. alcesa,b(n = 15) V. capreoli c V. sagittatus d V. sagittatus e Varestrongylussp.f1(n = 10) Varestrongylussp.f2(n = 20) V. alpenae g E. alcesh(n = 30) E. cervii(n = 30) E. rangiferij(n = 15)
Total length 221.5–373.7 255–341 260–305 268.8–295.7 281–374 348–400 310–380 377–445 392–445 381–490
(286.6 ± 40.81) (227–260) (233–305) (281 ± 11.9) (329) (377)   (417 ± 16) (420 ± 13) (426)
Nerve-ring§ 64.5–86.3 78–107 85–93 83–106 106–125 95–130
(74.1 ± 5.3)      (97)   (90 ± 16) (114 ± 5) (110)
Excretory pore§ 67.5–88.9 81–84 77–122.9 71–105 92–107 85–93 104–132 104–121 97–125
(78.8 ± 5.33)    (96±17.5) (84.5) (102)   (112 ± 7) (111 ± 4) (109)
Esophagus§ 111.6–182.5 70–83 115–151 134.4–161.3 88–155 151–180 155–180 173–236 175–206 163–230
(132.2±15.92) (120–140) (124) (147±15.9) (128) (168)   (188 ± 12) (187 ± 7) (191)
Esophagus/total length (%) 41.2–55.5 28–46 43–46 47–50
(46.3±3.85)     (38) (45)
Esophagus base width 6.2–15.7 8–15.5 9–15
(10.7 ± 3.51)     (10) (12)
Body at esophagus base 10.9–29.6
(19.5 ± 5.95)
Max body width 12.2–29.6 10–17 14–17 13.2–16.9 16–23 17–20 15–17 17–21 17–22 17–24
(20.1± 5.94) (11–14) (14) (15± 1.1) (19.5) (18)   (19 ± 1) (19 ± 1) (20)
Genital primordium§ 145.6–250.6 179–201 154–249.6 173–224 218–273 195–242 204–289 253–288 245–325
(202.3 ± 30.69)    (197±25.1) (206) (244)   (262 ± 16) (270 ± 10) (267)
Genital primordium/total length (%) 69.3–72.9 (70.7±6.04) 62–64 61–68 63–64
(63) (65)
Tail length 28.6–39.4 28–32 25–31 24.64–29.28 31–42 32–41 32–49 37–47 32–53
(36.4 ± 2.95)    (28± 1.63) (35) (38)   (42 ± 5) (43 ± 3) (44)
Tail spike 9.8–12.4 8 (9–10) 9.2–10.78 8–11 6–12 data not given data not given data not given data not given
(10.4 ± 0.68)    (9.6± 0.7) (9) (9)
Dorsal spine 2.8–3.5 2 data not given data not given 1.6–3 data not given data not given data not given data not given data not given
(3.1 ± 0.24)     (2)
  1. aPresent study – DSL recovered from lung washes and fixed in 70% ethanol and measured at 1000× magnification. The wide range for total length, especially the lower values might be attributable to the pulmonary origin (vs. feces) and fixation method.
  2. bonly measurements available in the original description [20], were total length, 305–441 μm and maximum width, 12 μm.
  3. cCombined sources compiled in [1], origin (lungs/feces) or fixation method not mentioned.
  4. dCombined sources compiled in [1], recovered from lungs, fixation method not mentioned.
  5. eDSL recovered from feces of red deer from the Vitinya wildlife-breeding station in the west Balkan Mountains, Bulgaria, not fixed and measured after iodine staining [45].
  6. fUndescribed Varestrongylus species found in caribou, muskoxen and moose across northern North America [14]. DSL recovered from feces of muskoxen from: (f1) Nunavik Region, Quebec, Canada, fixed in 70% ethanol and measured at 1600× magnification, (f2) near Aklavik, Northwest Territories, Canada, heat-relaxed in water and measured at 400× magnification.
  7. gV. alpenae DSL extracted from white-tailed deer feces, New York, USA in [45].
  8. hDSL recovered from feces of experimentally infected Eurasian elk, material was heat-relaxed in water and measured at 1000× magnification [8].
  9. iDSL recovered from feces of experimentally infected red deer, material was heat-relaxed in water and measured at 1000× magnification [8].
  10. jDSL recovered from feces of woodland caribou from Newfoundland, Canada. Material was heat-relaxed in water, magnification not mentioned [8].
  11. §Measurements from anterior end.
  12. Range of measurements are given followed by mean and standard deviation. Measurements are given in micrometers (μm).