Heth, Cobb, 1898

Phillips, Gary, Moulton, John K. & Bernard, Ernest C., 2020, Heth pivari n. sp. (Nematoda: Ransomnematoidea: Hethidae) from the indigenous North American millipede Narceus gordanus (Spirobolida: Spirobolidae), with keys for worldwide Heth spp., Zootaxa 4861 (4), pp. 486-514 : 507-508

publication ID

https://doi.org/10.11646/zootaxa.4861.4.2

publication LSID

lsid:zoobank.org:pub:8B330C85-5B40-48EF-8C17-48332637C1C9

DOI

https://doi.org/10.5281/zenodo.4426642

persistent identifier

https://treatment.plazi.org/id/8569BD6C-FF85-127A-31A9-1E3FFA5EFD5D

treatment provided by

Plazi

scientific name

Heth
status

 

Key to group 2 Heth spp.

1. Multiple cuticular knob–like papillae in anterior esophageal region............................................. 2

- Knob-like papillae absent near head region, rarely one or two close to the cervical collar............................ 9

2. Lateral cervical collar spines reaching or overlapping proximal base of anterior lateral spines........................ 3

- Lateral cervical collar spines not reaching anterior lateral spines................................................ 6

3. Anterior and posterior lateral spines about equal in length..................................................... 4

- Posterior lateral spines much longer than anterior spines ( Fig. 11G View FIGURE 11 ); anterior anal lip normal, without large lobe; female 2,340 – 3,230 μm long............................................................................... H. initiensis

4. Anterior anal lip with large lobe extending over anus; female 2,610 –4,225 μm long ( Fig. 11E View FIGURE 11 )............ H. impalutiensis

- Anterior anal lip not swollen into large lobe................................................................ 5

5. Shield length and width about equal ( Fig. 11M View FIGURE 11 ); female 1,365 –2,075 μm long.......................... H. taynguyeni

- Shield longer than wide ( Fig. 12C View FIGURE 12 ); females 2,550 –2,640 μm long................................. H. vietnamensis

6. Shield width twice that of its length; female 2,190 –4,483 µm long ( Figs. 2A, B, D View FIGURE 2 , 6A View FIGURE 6 )................. H. pivari n. sp.

- Shield length and width about equal, or length much longer than width.......................................... 7

7. Shield tapering, up to 3 times longer than wide ( Fig. 12A View FIGURE 12 ); females 2,180 –2,370 μm long................ H. tonkinensis

- Shield width and length similar, rounded or trapezoidal in shape................................................ 8

8. Shield rounded or ovoid; lateral spines less than 20 µm long ( Fig. 11A View FIGURE 11 ); female 1,105 –1,440 μm long.......... H. baudini

- Shield trapezoidal; lateral spines 28–30 μm long ( Fig. 11L View FIGURE 11 ); female 1,905 –2,575 μm long.................... H. taybaci

9. Cervical collar overlapping proximal base of anterior lateral spines............................................ 10

- Lateral cervical spines not overlapping anterior lateral spines................................................. 12

10. Eight longitudinal ridges extending from base of posterior lateral spines to vulva ( Fig. 11B View FIGURE 11 ); female 2,160 –2,600 μm long.............................................................................................. H. costata

- Longitudinal ridges absent............................................................................ 11

11. Anterior and posterior lateral spine pairs fused, 26–33 μm long; shield a semicircle, about twice as wide as long ( Fig. 11I View FIGURE 11 ); females 2,700 –3,024 μm long................................................................. H. orthopori

- Anterior lateral spines widely separated, 50 μm long; posterior lateral spines 55 μm long, bases closer but not touching ( Fig. 11K View FIGURE 11 ); females 2,010 –2,360 μm long........................................................... H. sutherlandi

12. Lappets continuous, not separated laterally................................................................ 13

- Lappets separated................................................................................... 15

13 Length of cervical spines along lappet edges irregular, some spines forked; anterior and posterior lateral spines with fused bases ( Fig. 12B View FIGURE 12 ); females 1,700 –2,800 μm long........................................................ H. tuxtlensis

- Cervical spines along lappet edges about the same size...................................................... 14

14. Shield forming a W-shape, length and width equal ( Fig. 11H View FIGURE 11 )............................................. H. juli

- Shield entire, not bilobed, well anterior to base of anterior lateral spines ( Fig. 11C View FIGURE 11 )..................... H. dimorphum

15. Wing-like lateral alae present; each pseudolabial plate with three conspicuous spines; cuticular collar with more than 100 spines; shield tapering, ( Figs. 12D View FIGURE 12 ); female length 2,400 –2,960 μm................................. H. xaniophora

- Lateral alae absent................................................................................... 16

16. Anterior lateral spines widely separated; shield of typical size ( Fig. 11J View FIGURE 11 ); females 1,970 –2,630 μm long.. H. ortonwilliamsi

- Anterior lateral spines fused basally; shield trapezoidal, small ( Fig. 11F View FIGURE 11 ); females 1,764 –1,962 μm long....... H. insularis