Floridobolus orini Shelley, 2014

Shelley, Rowland M. & Floyd, Samuel D., 2014, Expanded concept of the milliped family Spirobolidae Diplopoda: Spirobolida: Spirobolidea): Proposals of Aztecolini n. tribe and Floridobolinae / ini and Tylobolini n. stats.; (re) descriptions of Floridobolus and F. penneri, both Causey, 1957, and F. orini n. sp.; hypotheses on origins and affinities, Insecta Mundi 2014 (357), pp. 1-50 : 18-22

Floridobolus orini Shelley , new species

Figures 1–5 , 18–21 , 33

Type specimens. M holotype ( NCSM) collected by S.D. Floyd and J.L. Jarzynka, 1 August 2012, ca. 13.8 km (8.6 mi) ESE Lynn and 19.2 km (12 mi) ESE Ocala, along USFS rd. 13 (SE 241 st Ave., 1 st road past USFS rd. 97), 6.0 km (3.7 mi) S FL hwy. 40 (29°07.380’N, 81°45.354’W), Ocala National Forest, Marion Co., Florida. 6M paratypes (3 each deposited in NCSM, FSCA) taken by S.D. Floyd, 29 July 2013, ca. 11.2 km (7.0 mi) NW of type locality, along USFS rd. 38 west of USFS 11 (labeled as USFS 76 and 88 [NE 231 st Ave.], respectively, on Google and USFS maps), Ocala National Forest , Marion Co. , Florida. A discrepancy exists between the road signs and the numbers cited on both the official USFS map and the Google maps website. The signs are in good condition ; perhaps the roads have been renumbered and the maps have not been updated.

Diagnosis. Telopodite of anterior gonopod narrowly rounded apically, distal extremity directed ventrad, not coaxial with, and deeply demarcated from, midlength. Caudal surface of posterior gonopod acropodite without extraneous basal process.

Color in life ( Fig. 1–5 ). Body mostly gray to dark grayish olive; anterior margin of collum and pleurotergal fringes near legs dark yellowish, latter becoming wider caudad. Epiproct, paraprocts, and hypoproct gray blending into dark yellowish margins. Head dark grayish brown blending into brown on frons with lighter clypeal fringe. Prozona gray to yellowish.

Holotype. Length 72.5 mm; maximum width 9.7 mm, height 5.9 mm, W/L ratio 13.4%, depth/width ratio 60.8%, 48 rings.

Somatic features agreeing closely with those of F. penneri with following exceptions:

Clypeal setae 4–4, labral 10–10, merging with clypeal series and continuing for short distances along genal margins.

Margins of 2 nd pleurotergite rounded and lobe-like anteriad with thickened rims ( Fig. 2 ); meso- and metazona of remaining pleuroterga separated by faint grooves or sulci but not by clear, distinct lines; striae fainter, less elevated and ridge-like. Paraprocts smooth, margins not rugulose ( Fig. 5 ).

1 st and 2 nd legs short and markedly crassate. Coxal lobes as in F. penneri .

Gonopod structure as follows ( Fig. 18–21 ). Apices of anterior gonopod telopodites narrowly rounded, curved and directed ventrad, clearly demarcated from midlengths. Posterior gonopod leaning mediad in situ; prefemoral process a short, stubby, basal enlargement of telopodital stem; ventral branch of bifurcate projection of anterior acropodital surface subtriangular, dorsal branch rounded and angling dorsad, with narrow marginal rim; caudal acropodital surface without basal process, subapical lobe narrowly rounded, extending beyond level of apical lobe.

Female unknown.

Paratypes. The paratypes agree closely with the holotype in somatic features and in the coxal lobes. Lengths range from 68.7–80.4 mm; maximal widths, caudal to midlengths, vary from 10.8–12.6 mm; W/L ratios range from 13.9–17.2%, and ring numbers, including the collum and epiproct, vary from 47–50, with an average of 47.8. The apices of the anterior gonopod telopodites can be slightly longer, shorter, broader, narrower, and more acuminate than the condition in the holotype. Branch proportions of the bifurcate projection of the anterior surface of the posterior gonopod acropodite vary, and the anterior branch is prolonged in two individuals.

Ecology ( Fig. 22–26 ). The holotype was coiled under decaying sand pine ( Pinus clausa ) boards about 15 ft. from a dirt road in late afternoon in xeric “Big Scrub” habitat at an elevation of approximately 28 m (93 ft) ( Fig. 22–23 ). The site, ca. 208 km (130 mi) to the north of F. penneri , appeared to have once been logged to restore habitat for the endangered Florida Scrub Jay ( Aphelocoma coerulescens ). Moisture remained from precipitation the previous day, which may have facilitated the discovery because the well drained, loose, sandy soil ( Fig. 22 ) dries quickly and likely forces millipeds underground for extended periods of time. Predominant vegetation included three species of small, evergreen, shrubby oaks ( Fig. 23 ) – myrtle oak ( Quercus myrtifolia ), Chapman’s scrub oak ( Quercus chapmanii ), and sand live oak ( Quercus geminata ) – interspersed with scrub palmettos ( Sabal etonia ) ( Fig. 22–24 ), prickly pear cacti ( Opuntia humifusa ammophila ) ( Fig. 22, 24–26 ), and scrub wild olives ( Cartrema floridana ). Younger sand pines were evenly scattered through the area with Florida rosemary ( Ceratiola ericoides ) in open spots. The roadside was bordered for most of its length with perennial dog fennel ( Eupatorium capillifolium ) to a width of around 3 m (10 ft). An expansive forest of mature sand pines ( Fig. 26 ) with an understory of small endemic shrubs surrounded the more open spot where F. orini was discovered. The milliped is primarily nocturnal or crepuscular because daytime surface activity would render it vulnerable to desiccation. SDF has visited the type locality frequently over four years and found only N. gordanus until the serendipitous discovery of F. orini .

SDF surveyed spirobolidans on 9 July 2013 from 9:00 pm - 3:30 am along a three mile section of dirt road and recovered 38 individuals of F. orini , six designated paratypes. The area had received heavy precipitation two hours earlier, which likely induced millipeds to leave their burrows and wander; 33 individuals were walking on a dirt road, and five were less than 100 yards off it. The first individual was encountered at 10:45 pm, but the majority emerged a couple of hours later with peak activity being around 2:00 am when the ambient temperature dropped to 76°F. While mating and feeding were not observed, all individuals were actively moving on the sandy substrate; none were climbing in vegetation as often occurs with C. spinigerus . SDF searched for F. orini up to 16 km (10 mi) away but only N. gordanus , absent from the area where F. orini was found, was observed crossing roads. Floridobolus orini appears to prefer higher sandy elevations that lack the leafy detritus favored by N. gordanus , whose southern, Lake Wales Ridge population ( Keeton 1960a) prefers sandy areas with little or no humus and leaf-mold, a different biotope from that of F. penneri . Individuals of N. gordanus burrow deeply into sand during day, forming round holes easily located by observers, and emerge at night to feed on rotting logs, the most ready source of food. Floridobolus orini may occupy a subsurface habitat and occur throughout sandy, “Big Scrub” habitat in the Ocala National Forest, which extends, eastwest, from western Marion to western Volusia cos.; a graduate student is detailing its range.

Distribution ( Fig. 13 ). Known only from the type and paratype localities, which are around 11.2 km (7 mi) apart in the Ocala National Forest, Marion Co., Florida.

Etymology. We are pleased to name this species for Orin McMonigle, who recognized the holotype as a form of Floridobolus , sent it to RMS, and agreed to its placement in the NCSM invertebrate primary type collection.

Remarks. Anatomical differences between the congeners are detailed in Table 4.

Figures

Figure 13. Distributions of Floridobolini and Floridobolus. Star, type locality of F. orini. Black line, known and projected distributions of F. penneri on the Lake Wales Ridge. AR, course of the Apalachicola River in Florida. H, Highlands Co. M, Marion Co. P, Polk Co.

Figure 33. Ring profiles in Spirobolidae. Left two rings, transversely ovoid profile shown by Floridobolinae/ Floridobolini. Right two rings, rounded profile demonstrated by Floridobolinae/Tylobolini and Spirobolinae. Photo courtesy of O. McMonigle.

Figures 1–5. Floridobolus orini holotype. 1) Head, collum, and anterior pleurotergites, dorsal view. 2) The same, right sublateral view. 3) Entire body, dorsal view. 4) The same, dorsolateral view. 5) Paraprocts, epiproct, and caudal pleurotergites, caudolateral view.

Figures 14–21. Floridobolus spp., gonopodal features. 14–17) F. penneri holotype.14) Left anterior gonopod, anterior view. 15) Telopodite of left posterior gonopod, anterior view. 16) The same, caudal view. 17) Bifurcate projection of anterior surface of the same, anteriomedial view. 18–21) F. orini holotype. 18) left anterior gonopod, anterior view. 19) Telopodite of left posterior gonopod, anterior view. 20) The same, caudal view. 21) Bifurcate projection of anterior surface of the same, anteriomedial view. A and C, anterior and caudal surfaces, respectively, of posterior gonopod acropodite. at, anterior gonopod telopodite. ce, coxal endite. db, dorsal branch of bifurcate projection. s, sternum. vb, ventral branch of bifurcate projection. asterisk (*), prefemoral process. x, extraneous basal process.

Figures 22–26. “Big Scrub” habitat at the type locality of F. orini. 22) Sand Pine (Pinus clausa) boards that sheltered the holotype near the base of a scrub palmetto (Sabal etonia). 23) Broad environmental view with young Pinus clausa beyond the boards. 24) Lightly moist, porous sandy substrate, potential refuge for both F. orini and N. gordanus, beneath partly decayed Pinus clausa boards near base of Sabal etonia. 25) Prickly pear cactus (Opuntia humifusa). 26) Xeric Pinus clausa forest adjacent to more open scrub habitat where F. orini was discovered.