Floridobolus penneri Causey, 1957

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 : 16-18

Floridobolus penneri Causey, 1957

Fig. 14–17 , 33 .

Floridobolus penneri Causey, 1957:206–207 , fig. 1–3. Keeton, 1959:2–7, pl. 1, fig. 1–9, pl. 2, fig. 10–16; 1960b:137–139, fig. 8. Deyrup, 1994:254–256, unnumbered fig. Hoffman, 1999:48. Shelley, 2001a:243 –244.

Type specimens. M Holotype ( AMNH) collected by L.R. Penner, 8 August 1956, at the junction of Florida highway 70 and US highway 17 in Arcadia (16 km (10 mi) W of ABS and Lake Placid), Highlands Co., Florida; M Paratype ( FSCA) taken by same collector at same locality on 19 July 1957. The reputed occurrence along US highway 70 ( Causey 1957, Keeton 1959), which lies hundreds of miles to the north in North Carolina and runs west to Arizona, is obviously incorrect.

Diagnosis. Telopodite of anterior gonopod apically flattened and blunt, distal extremity directed ventromediad, coaxial with, and shallowly demarcated from, midlength. Caudal surface of posterior gonopod telopodite with extraneous, closely appressed, basal process.

Color in life. Uniformly slate gray ( Deyrup 2012).

Holotype (adapted from Causey [1957] and Keeton [1959, 1960b]). Fragmented, about 92 mm long, maximum width 11.6 mm, maximum height 10.3 mm, W/L ratio 12.6%, depth/width ratio 88.8%; 49 rings.

Head smooth, glossy/glabrous, with only clypeal (6–6) and labral (9–9) setae. Epicranial suture strong, continuous through interantennal region with frontal suture and continuing to clypeus. Interantennal isthmus broad, 2.4 mm; antennae widely separated. Genae broadly rounded, without impressions, ends extending slightly beyond adjacent cranial margins; width across genal apices 3.6 mm. Antennae short and stout, extending backwards to midlength of collum; 2 nd antennomere elongate, 3–6 clavate, 7 short and truncate, with four terminal sensory cones, no other sensory structures evident; relative lengths of antennomeres 2>3=4>1=5>6>7; 1–2 subglabrous, 3–4 with rows of hairs on dorsal surfaces, 5 with scattered hairs and long ones ventrad, 6 moderately pilose, 7 densely so. Around 63 ocelli arranged in sublinear, horizontal and vertical rows, forming irregularly rounded cluster directed ventrolaterad; vertical rows, medial to lateral, with 4, 7, 10, 10, 9, 9, 6, 5, and 3 ocelli.

Collum about 3x length of 2 nd pleurotergite, narrowing ventrolaterad, slightly overhanging epicranium, anterior margin elevated into rim, demarcated by sharp groove. 2 nd pleurotergite extending ventrolaterad below ends of collum, margin lightly scalloped; remaining pleuroterga subsimilar throughout body; prozona separated from mesozona by narrow lines, meso- and metazona separated by stronger ones. Ozopores strong, distinct, arising from mesozona just anterior to metazonal suture. Ventrolateral striae fewer on anterior segments but generally strong and distinct, becoming progressively more elevated and ridge-like/subcarinate ventrad, extending dorsad for around ¼ of pleurotergal circumferences.

Legs set close together with opposing coxae essentially touching; prefemora with small conical to rounded lobes, becoming progressively smaller and more rounded caudad. Postgonopodal legs subsimilar throughout body; coxae with slight lobes and a single ventral hair, becoming progressively smaller and more rounded caudad. Podomeres becoming progressively more hirsute distad with strong, stout, ventral setae; claws gently curved. Hypoproct glabrous, subtrapezoidal; distal margin linear, anterior corners prolonged laterad; paraprocts glabrous, slightly re-entrant and without rims, medial margins coriaceous to lightly rugulose.

Gonopod structure as follows ( Fig. 14–17 ). Apices of anterior gonopod telopodites linear and blunt, directed ventromediad, weakly and shallowly demarcated from midlengths. Posterior gonopod leaning ventromediad in situ; prefemoral process (asterisk) an inconspicuous, nubbin-like structure; ventral branch of bifurcate projection (vb) from anterior acropodital surface (A) rounded and subupright, connecting through shallow indentation with stronger, broader dorsal branch (db), latter marginally sublinear with dorsal corner slightly prolonged; caudal acropodital surface (C) with apical lobe substantially broader than subapical, also with closely appressed. inconspicuous basal process extending mediad beyond margin, corners slightly prolonged.

Female as characterized by Keeton (1959).

Variation. Without sexing them, Keeton (1960b) addressed variation among 25 adults from the ABS. Ring counts varied from 47–51, but 16 specimens possessed 48 rings and five had 49. Lengths varied from 60–92 mm and widths from 10.0–12.8 mm ; labral setae varied from 13–24; and the number of ocelli per ocellarium ranged from 52–66. Though not specifically measured, the convexities on the gnathochilarial mentums seemed constant; however, the lobes on the ambulatory prefemora varied greatly and were often small and inconspicuous.

Ecology. According to Keeton (1959), topotypes collected in 1958 were found in a sandy locality with sparse palmetto vegetation. Being nocturnal, they actively crawled over the sand at nights but were inactive during days, resting under pieces of wood and old fence posts. The near topotypes he ( Keeton 1960b) later received were found only in areas with woody plants, often fed on palmetto fruiting bodies, and were abundant under dead logs that were not deeply buried in sand, in contrast to N. gordanus , which was common in open areas. The latter made round tunnels and burrowed deeply into the sand, but F. penneri apparently did not do so. Deyrup (1994, 2012) observed that, in captivity, it fed on partly decomposed scrub oak leaves ( Quercus ? inopina) and small twigs, refusing fresh leaves. Pitfall traps capture adults in the fall but rarely juveniles any time of year, suggesting that F. penneri may only be surface active during reproductive season.

Distribution ( Fig. 13 ). Known only from the Lake Wales Ridge, Polk and Highlands cos. ( Deyrup 1989, 1994, 2012; Hoffman 1999; Shelley 2001a ), ranging from Lake Wales (city) to the vicinity of Venus, in southernmost Highlands Co. The species thus occupies a narrow, irregularly linear, “zigzagging” range that is roughly 91 km (57 mi) long and 16 km (10 mi) wide. Places where F. penneri has been taken include Camp Florida YMCA Camp on US hwy. 27 (now a housing development); Virginia Avenue in Highlands Park Estates; NE Lake Placid; and the ABS. In addition to the types, specimens were examined from the following two sites:

Florida: Highlands Co., Hendry Ranch ENE Venus and US hwy. 27, M, 1 October 1987, M. Deyrup ( NCSM) ; and Sebring, F, 10 June 1960, H. V. Weems, Jr. ( FSCA) .

Remarks. Keeton (1959) characterized the legs as “exceedingly short” and “hardly visible when the animal is walking.” As Floridobolus ’ and F. penneri ’s flattened, transversely ovoid profiles ( Fig. 33 ) are wider than high, their bodies shield the legs in dorsal views ( Fig. 3 ) and protect them from breakage in tight burrows; contrastingly, legs are partly visible from above in the rounded profiles of Narceus spp. Because juvenile ring counts correspond with those of adults, Keeton suggested that F. penneri rapidly attains the adult ring number then increases in size and sexual maturation in subsequent molts. Deyrup (2012) suggested that F. penneri matures slowly and recommended that it be considered a species of “conservation concern.”

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 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 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.