Speleopsobius weaveri, Shear, 2018

Shear, William A., 2018, The centipede family Anopsobiidae new to North America, with the description of a new genus and species and notes on the Henicopidae of North America and the Anopsobiidae of the Northern Hemisphere (Chilopoda, Lithobiomorpha), Zootaxa 4422 (2), pp. 259-283 : 271-277

Speleopsobius weaveri , new species

Figs. 1–25

Material examined: Holotype female from Spider Cave, Gooding Co., Idaho, 43.017506°N, 114.835403°W, collected 17 July 2000 by D. A. Hubbard, Jr.; paratype male from Tee Cave, Lincoln Co., Idaho, 43.0812°N, 114.4099°W, collected 18 July 2007 by D. A. Hubbard, Jr.; paratype male from Tee Cave, collected 30 June 2007 by C. Richart and A. Fusek; paratype female from Tee Cave, collected 16 July 1999 by D. A. Hubbard, Jr. The type material includes SEM stub WS 29-8. All specimens deposited in the CAS. As the largest (and thus most likely to be fully mature) and only complete specimen, the Spider Cave female was selected as the holotype. Spider Cave is sometimes known as Octopus Cave.

Diagnosis: As for the genus, see above.

Etymology: The species epithet thanks and honors Dr. Andrew A. Weaver, Professor of Biology Emeritus, College of Wooster, Wooster, Ohio, whose extensive unpublished work on North American centipedes inspired this study and who was an early mentor (from 1959 onward) of the author.

Description: Based on female holotype from Spider Cave: Length 20.5 mm. Color uniformly pale yelloworange ( Fig. 1 ). Head. Length of head shield 1.8 mm. Transverse suture of head ( Fig. 3 ) parabolic, anteriorly slightly sinuate, extending back 42% of head length. Median notch shallow, median furrow (suture) absent. Posterior margin of head strongly rebordered, rebordering interrupted in posterior median line by short suture or notch. Head depigmented anterior to antennocellar sutures. Setation of head sparse, some setae rubbed off; two pairs of setae near median notch; at least four long setae on each side of head posterior to transverse suture; setae of head shield disc all very small, probably four pairs arranged symmetrically. Antennae ( Fig. 1 ) long, approximately half as long as body, with 60 articles, the two basal articles larger than more distal ones, well-furnished with slit sense organs around distal rim. Tömösvàry organ small, oval, on cephalic pleurite. Mouthparts. Clypeus projecting, rounded, with single large seta medially, two smaller setae on either side. Labrum deeply notched, with single median hastate tooth; labral fringed setae narrow, feathery, with branches all along length of setae. Mandibles ( Figs. 7, 8 ) with about 12 slightly curved aciculae, each minutely dentate along both sides of distal third. Four mandibular teeth, distal the largest, decreasing in size ectally, with three cusps (outer cusp obselete on ectalmost tooth); accessory denticles as small acute nodules decreasing in size proximally. Fringe of about 10 branching bristles, decreasing in size mesally, with broad bases, fringe beginning at base of each bristle, extending to tip; bristles abruptly transitioning to field of finely branched scales extending to furry pad. Furry pad not clearly delimited from scale field, consisting of finely branched, narrow scales. First maxillae ( Fig. 9 ) with broad but short sternite, sternite fused to coxae. Coxal process with about six simple setae. Telopodite with inner row of at least eight plumose setae, numerous simple setae form irregular row lateral of plumose setae. Both telopodite articles with numerous simple setae laterally. Second maxillae ( Figs. 11 – 13 ) with short, subtriangular coxae; telopodites with four articles, the trochanter short, both joints present; femur curved, about twice as long as tibia; tarsus slightly longer than tibia. Inner surface of tarsus ( Fig. 12 ) concave (perhaps poorly sclerotized) densely set with plumose setae. Claw with perhaps five subequal branches, claw subtended laterally by two long setae plumose in their distal halves ( Fig. 13 ). Legs. Forcipules robust ( Fig. 4 ). Pleural collar continuous, without median sclerite or median suture. Coxosternite broad, coxal lobes set off by shallow grooves, lateral margins of sternal part gently, evenly curved, distal margin slightly indented, disc with four pairs of prominent setae, scattered setae distally. Coxosternal teeth 3 + 3; porodonts absent or indistinguishable from setae. Prefemur of telopodite about twice as long as broad, sparsely setose. Femur and tibia of telopodite subequal, broader than long, with few setae. Tarsungulum (“claw”) about 5/6ths as long as prefemur, tarsal section set off from pretarsal section by small median nodule, pretarsal section gently curving, about three times longer than tarsal section. Tergites ( Fig. 1 ) smooth and shining, with few scattered very small setae across surface, with three or four marginal setae including one at posteriolateral angle, posterior margins with paired paramedian setae. All tergites narrowly rebordered laterally and posteriorly. Tergites 3, 5 and 8 with median embayment, deepest and most obvious on tergite 8. Tergite 14 with slightly extended, triangular posteriolateral corners. Other tergites with straight or slightly convex posterior margins. Sternites sparsely setose, posterior margins straight, with posterior rows of four to six setae. Spiracles on segments 3, 5, 8, 10, 12 and 14. Posteriormost legs. Coxal pores in single series, round to broadly oval, distribution 3, 5, 5, 6 on coxae 12 – 15, first in series on coxa 15 about ½ the size of more distal pores. Coxa 15 ( Fig. 14 ) with small, but distinct, coxal spine bearing dark, sclerotized tip without distinct articulation. Coxa 14 distally rounded, spine absent. More anterior coxae without spines. Proportions of legs 12–15 as in Figs. 18 – 25 , Table 2. Tibia of legs 1–13 with distal spine. Legs 13–15 with biarticulate tarsi. Tarsi of more anterior legs proportionally similar, with definite flexion point at same relative position as articulations of tarsi 13–15, but without distinct joint. Claws of legs 1–12 ( Fig. 19 ) with basal, anterior accessory branch, basal, posterior bristle little more than half length of claw, claws 13–14 with posterior bristle only ( Figs. 21, 23 ), claw 15 ( Fig. 25 ) lacking both accessory branch and bristle.

Sternite of segment 15 narrowed posteriorly, posterior margin straight, four prominent setae, several thinner ones along posterior margin ( Figs. 14, 15 ). First genital sternite with median sulcus, distomesally with four large setae, large seta at posteriolateral angle. Gonopods. Gonopodal ( Fig. 15 ) first article densely setose on lateral surface, mesal surface glabrous, distoventrally with two subequal acuminate spurs. Second article about half length of first, 5 – 6 setae on lateral surface, mesal surface glabrous; terminal article shorter than second article, with single large lateral seta, one or two much smaller ones, claw simple, acuminate.

Male paratype ( Figs. 2 , 5, 6 , 16, 17 ) collected by D. A. Hubbard from Tee Cave differing from female holotype as follows: length, 17 mm. Tergites 3, 5, 8, and 10 with triangular embayment posteriorly, tergite 12 with concave posterior margin ( Fig. 2 ). Coxal pores 3, 4, 4/5, 5, proximal pore on coxa 15 less than half diameter of largest pore (Figs. 16,17). First genital sternite ( Fig. 17 ) entire, densely setose. Gonopod ( Fig. 17 ) basal article with about eight setae, second article about half length of first, third article subconical, terminal filamentous part short, about half length of third article, sharply set off at base. Anal coxosternite with 6 – 8 setae, paired glands ( Figs. 16, 17 ).

Notes: The podomere proportions of the last three pairs of legs contrast with the proportions of the 12th legs, and are remarkably consistant. Taking the length of the prefemur as 1.0, the respective proportions of the femur, tibia, first tarsus and second tarsus of the 13th legs are 1.2/1.5/1.5/0.7, of the 14th legs 1.2/1.5/1.4/0.6, and of the 15th legs 1.2/1.3/1.2/0.7. The Hubbard male paratype may not be fully mature, perhaps being a maturus junior (epimorphic stage VI), but has 60 antennal articles. The difference in the male tergites may be an expression of sexual dimorphism, but could possibly indicate that the Tee Cave specimens are not the same species as the one in Spider Cave, since the male paratype collected by C. Richart and the female paratype have the same distribution of tergite embayments as the male collected by D. Hubbard. The Richart male’s antennae are not complete; coxal pores are 3, 4, 4, 4, so in comparison with the other male paratype, the specimen might be a prematurus (epimorphic state V). The Tee Cave female specimen is likely also immature, based on the lower number (52/54) of antennal articles and coxal pores counting 3, 4, 4, 4. To fully resolve the identity of both of these populations, additional material is required.

Ecology: Troglobiosis is indicated in this species by the extremely long antennae with many additional anntennomeres, the long, thin legs and the large size (troglobiotic gigantism). Via Google Earth, I examined the area immediately around Spider Cave, which is situated in a lava outcrop just off an unpaved road. Multiple tire tracks suggest the cave is frequently visited. The surroundings appear to be typical desert or steppe grasslands, with considerable bare soil and scattered outcrops of black lava. I am certain that no henicopid or anopsobiid centipede could be supported in this surface habitat.

Figures

FIGURES 1, 2. Speleopsobius weaveri, n. sp. 1. Female holotype from Spider Cave, dorsal view. 2. Male paratype from Tee Cave, dorsal view. Numerals indicate tergite numbers.

FIGURES 3–6. Speleopsobius weaveri, n. sp. 3. Head of female, dorsal view. 4. Same, ventral view. 5. Head of male, dorsal view. 6. Same, ventral view.

FIGURES 7–9. Speleopsobius weaveri, n. sp. 7. Mandible, ectal view. 8. Same, medial view. 9. First maxilla. a, aciculae; t, mandibular teeth; cx, coxosternum; cp, coxal process; t1, first article of telopodite; t2, second article of telopodite.

FIGURES 10–13. Speleopsobius weaveri, n. sp. 10. Plumose setae of epistome. 11. Telopodite of second maxilla. 12. Tarsus of same. 13. Tip of tarsus.

FIGURES 14–17. Speleopsobius weaveri, n. sp. 14. Posterior end of female, ventral view. 15. Female gonopods, ventral view. 16. Posterior end of male, ventral view. 17. Gonopods of male, ventral view. Cx14, coxa 14; cx15, coxa 15; s14, sternite 14; s15, sternite 15, gs, genital sternite; gp, gonopod; svo, seminal vesicle opening; glo, gland openings.

FIGURES 18–25. Speleopsobius weaveri, n. sp. 18. Leg 12. 19. Claw of leg 12. 20. Leg 13. 21. Claw of leg 13. 22. Leg 14. 23. Claw of leg 13. 24. Leg 15. 25. Claw of leg 15.