Nannarrup hoffmani, FODDAI & BONATO & PEREIRA & MINELLI, 2003

FODDAI, DONATELLA, BONATO, LUCIO, PEREIRA, LUIS ALBERTO & MINELLI, ALESSANDRO, 2003, Phylogeny and systematics of the Arrupinae (Chilopoda Geophilomorpha Mecistocephalidae) with the description of a new dwarfed species, Journal of Natural History 37 (10), pp. 1247-1267 : 1256-1260

Nannarrup hoffmani n. sp.

(figures 2–27)

Type material examined. H  : female, 41 pairs of legs, body length 10.3 mm, from USA, New York City, Central Park, North Woods , ex leaf litter, Berlese , 21 April 1998, K. Cartey leg. ;     : eight juvenile specimens, total length 5.5–6.5 mm; one incomplete specimen, probably adult, represented by the head and the 29 most anterior leg-bearing segments, 7.5 mm, all from USA, New York City, Central Park, The Ramble , ex leaf litter, Berlese , 4 September 1998, K. Cartey leg.

Depository of types. Female holotype and eight paratypes: American Museum of Natural History , New York, USA ; one paratype: A. Minelli, Department of Biology , University of Padova, Italy .

Description

Female holotype: 41 pairs of legs, body length 10.3 mm, maximum body width 0.4 mm.

Body gradually attenuate, both anteriorly and posteriorly (figure 2).

Colour (of preserved specimen in alcohol) very pale yellow, cephalic plate and forcipular segment pale ochre.

Antennae. Antennae relatively short, ca 2.3 times as long as the cephalic plate, distally only slightly attenuate; articles II – V and XIV longer than their greatest width, all remaining articles slightly wider than long. Shape as in figures 3, 5. Setae on article I– XIV progressively shorter and relatively more numerous towards the tip of the appendage. Articles I and II each with one distal whorl of long setae, articles III–VII each with one distal and one proximal whorl of long setae; in articles VIII– XIII a third irregular whorl of setae is present. Density and distribution of setae on the ventral side similar to those of the dorsal side. Terminal article with ca eight or nine claviform sensilla on the external side and ca four on the internal side (figures 4, 6). Distal end of this article with ca two specialized sensilla (figure 3), not divided apically but with a wide flat ring at mid-length; length of these sensilla similar to the length of the claviform sensilla. Dorsal and ventral surface of articles II, V, IX and XIII with very small sensilla, not divided apically. On the ventral side these sensilla are restricted to an internal and apical area and are represented by two different types, a and b. Type a specialized sensilla are similar to those of the apex of the terminal article but smaller and with a very poorly developed flat ring at mid-length (figure 4a); type b setae very thin (figure 4b). On the dorsal side, specialized sensilla are restricted to an external-apical area and are represented by three different types, a, b and c. Types a and b sensilla are similar to a and b of ventral side; type c sensilla resemble type a sensilla in having a wider basal part and a thin apical half (figure 4a–c). Distribution of a, b and c sensilla as in table 3.

Cephalic plate. Cephalic plate slightly longer than wide (1.2:1). Frontal line absent. Whole surface covered with well-marked areolation. Posterior setigerous sulci absent. Shape and chaetotaxy as in figures 7, 8. Lateral margins only slightly convex.

Clypeus. Clypeal area absent. Paraclypeal sutures complete. Two clypeal plagulae with rare micropores, occupying less than one-sixth of the clypeal length. Setae of areolate portion of clypeus: 1+1 postantennal, 2+2 median, 4+4 praelabral (figure 9). Clypeal insulae absent. Two additional smooth areas along the posterior part of the paraclypeal sutures.

Buccae. Without setae (figure 9). Stilus well chitinized but short. Spiculum absent.

Labrum. Side-pieces only incompletely divided into anterior and posterior alae by a weak chitinous line (figure 10). Longitudinal stripes on the posterior alae absent. Posterior margin of side-pieces with slightly visible short fringes, restricted to the medial third. Side-pieces medially in contact. Mid-piece much longer than wide (ratio 2:1), darker than the remaining part of labrum; its broader basal half is partly overlapped by the side-pieces. Mandibular fulcrum vestigial.

Mandible. Mandible provided with four pectinate lamellae at least (figure 11). Ventral surface hairy.

First maxillae. Coxosternum medially divided, without setae, apparently not areolate. Medial projections of coxosternum well developed, provided with 2+2 setae and 4+3 small sensilla. Medial projections and telopodites distally hyaline, separated from the coxosternum by a distinct suture. Telopodite uniarticulated, with one (two) large seta(e) (figure 12). No lobes on either coxosternum or telopodites.

Second maxillae. Coxosternum medially undivided, without suture, with 2+2 setae along the anterior margin and 3+2 setae in a more posterior row, arranged as in figure 12; anterior margin slightly concave; isthmus areolate. Metameric pores opening posteriorly. Telopodites triarticulate, very short, neither surpassing nor reaching the medial projections and telopodites of the first maxillae. Claw of the telopodite virtually absent, represented by a short spine only.

Forcipular segment. When closed, telopodites remain far behind the anterior margin of the head (figure 8). Forcipular tergum trapeziform, with anterior and posterior margins, respectively, covered by the cephalic plate and the tergum of first leg-bearing segment; 1+1 anterior setae and 3+3 setae of similar length in a posterior row. Mid-longitudinal sulcus of tergum not visible. Trochanteropraefemur provided with one strong pigmented tooth at the distal internal margin; femur and tibia short, without teeth (figures 13, 14). Tarsungulum with a well-developed and slightly pigmented basal tooth. Internal margin of tarsungulum smooth. Coxopleural sutures running on the ventral side for their posterior half only. Chitinous lines absent. Calyx of poison gland long (length to width ratio 7.2:1), cylindrical and nearly symmetric, located at the level of the intermediate articles (figure 14). Chaetotaxy of coxosternum and telopodites as in figure 8.

Terga. Two paramedian sulci visible on the terga of the anterior half of the body; those of the posterior half apparently without sulci. Chaetotaxy of a typical tergum as in figure 15.

Sterna. Pore fields absent. All sterna slightly longer than wide and with similar chaetotaxy (figures 16–22). Sterna I– XIV with a very well-developed process at the posterior margin, protruding into the next sternum; sternum XV with a faint process. Praesternum very short, divided in the middle, shallowly telescoping into the next sternum. Rhachis visible on a few anterior sterna, represented by a very shallow mid-longitudinal thickening, anteriorly not furcate.

Legs (last pair excepted). First pair much shorter than the second one (ca 1:2). All legs with similar dorsal and ventral chaetotaxy (figures 23, 24). Claws ventrally with two basal small parungues, nearly equal in length (figure 25).

Last leg-bearing segment. Praetergum not accompanied by pleurites but incomplete trace of sutures are present at both sides (figure 26). Praesternum divided along the sagittal plane. Sternum trapeziform, its posterior margin swollen, covered by numerous long setae. Shape and chaetotaxy of tergum and sternum as in figures 26, 27. Coxopleura protruding at their medial ventral side, covered by numerous long setae. Coxal organs single, each with an independent opening; coxal pores mostly placed on ventral surface of the coxopleuron, seven on the right, eight on the left side (figure 27). Telopodite not inflated, of six articles; shape and chaetotaxy of dorsal and ventral side as in figures 26, 27. Praetarsus represented by a very small spine.

Terminal segments. Gonopods apparently uniarticulate, with three long setae each (figure 27). Anal pores opening laterally.

Male. The following distinctive traits are given on the basis of a juvenile specimen, being the only male available. Last pair of legs not inflated. Gonopods biarticulate, conical in outline, very widely separated from one another.

Etymology. The species is named after our friend Dr Richard L. Hoffman.

Remarks. The adult condition of the female holotype is indicated by the presence of spermathecae full of spermatozoa, at the level of XXXVIII–XXXIX leg-bearing segments.

Characters in table 4 differentiate Nannarrup hoffmani n. sp. from Arrup pylorus , the type species of Arrup Chamberlin, 1912 , the genus most closely related to Nannarrup (see above under Materials and Methods).