Anaulaciulus multiarticulatus, Mikhaljova, Elena V., Golovatch, Sergei I. & Chang, Hsueh-Wen, 2011

Mikhaljova, Elena V., Golovatch, Sergei I. & Chang, Hsueh-Wen, 2011, The millipede genus Anaulaciulus Pocock, 1895 in Taiwan, with descriptions of four new species (Diplopoda, Julida, Julidae), Zootaxa 3114, pp. 1-21 : 9-11

Anaulaciulus multiarticulatus sp. nov.

Figs 27–39

Material examined. Holotype: male ( NMNS, 6702 – 0 0 8, D – 0293), Taiwan, Nantou County, Huisun timberland, 27 December 1997, leg. S.H. Wu; Paratypes: 7 males, 7 females, 5 juveniles, ( NMNS, 6702 – 0 0 9, D – 0293), 1 male, 2 females ( IBSS), 1 male, 1 female ( ZMUM), 1 male, 1 female (NSYSUB), 1 male, 1 female ( HNHM), same locality, together with holotype, 27 December 1997; 4 males (1 male devoid of gonopods, presumably lost), 1 female ( NMNS, 6702 – 0 10, D – 0294), 1 male, 1 female ( IBSS), same locality, 27 December 1997, all leg. S.H. Wu.

Diagnosis. Differs from congeners mainly by the shape of the gonopod opisthomere showing an anterolateral lamella broadening at the lateral margin distally into a rounded lobe, as well as by the subrectangular promere with its apex ranging from rather clearly rounded to excavated. This new species differs from the obviously especially similar A. oligosegmentatus sp. nov. by the lesser body diameter and more numerous segments.

Description. Male. Length 19 – 35 mm, vertical diameter 0.9 – 1.1 mm (the overwhelming majority of males show a vertical diameter of 1.0 mm), with 58(– 8), 59(– 9), 60(– 9), 61(– 5), 63(– 6), 64(– 4), 65(– 6), 66(– 5), 67(– 7), 68(– 6), 69(– 5), 69(– 7), 80(– 3) segments, excluding telson. A male with 64(– 4) body segments showing last podous segment with legs developed only on the right side. Coloration brown or light brown with three narrow, longitudinal, dark brown stripes, one mid-dorsal and two lateral level to ozopores, so that dorsum showing two somewhat lighter, broad, ribbon-shaped, longitudinal stripes, these being less distinct as compared to those in A. oligosegmentatus sp. nov. Collum with two transversely-oval, large, yellowish spots. Segments in front of telson can also be with two transversely-oval yellowish spots on dorsal side. Clypeolabral part of head lighter. Anal valves lighter, as usual. Antennae and legs brown or beige, eye patches black.

Eye patches subtriangular, composed of at least 26 ocelli. Labral setae as in A. immensus sp. nov. Gnathochilarium as in A. oligosegmentatus sp. nov. Length ratios of antennomeres 2–7 as 2.7:2.4:2.4:2.3:1.5:1, width ratios as 1.1:1.1:1.2:1.5:1.4:1, respectively.

Ozopores lying behind stricture without touching it. Striations on metazona not reaching caudal margin, thus making metazona look like being rimmed caudally; 15 – 16 striae on metazonital surface between dorsal midline and ozopore, or 7 – 8 striae per square lying between ozopore and axial line. Antennomeres 5 and 6, striations on dorsum and caudal projection of epiproct (including a tiny claw-shaped process) as in A. oligosegmentatus sp. nov.

Legs as in A. oligosegmentatus sp. nov., but pads on femora absent. Anterior legs with narrow pads on postfemora. Claw at base with a presumably long filament ventrally, but without accessory claw dorsally. All claws examined under a microscope (seven claws in 2 – 3 individuals) showed a ventrobasal stump which could presumably be considered as the rest of a long, broken-off filament, but hardly a short filament. Legs 1 with strong setae ventrally and a ventral papillate knob on telopoditomere 2, apex with several low papillae ( Fig. 27 ). Penes of medium length, deeply bifid ( Fig. 28 ).

Gonopods. Promere subquadrate, its mesal margin slightly curved rectangularly caudad; flagellum relatively long; rudimentary telopodites well-visible ( Fig. 29 ). Apex of promere varying from relatively well rounded to excavated with a rounded mesal outgrowth ( Figs 35 – 39 ), this variation being observed even within a single individual, possibly as a result of abrasion with age ( Figs 37, 39 ).

Opisthomere ( Figs 30 – 32 ) as in A. oligosegmentatus sp. nov., but distal part of al narrower.

Female. Length 17.5 – 27 mm, vertical diameter 1.0 – 1.4 mm, with 53(– 6), 53(– 7), 54(– 7), 54(– 8), 57(– 4), 58(– 5), 59(– 5), 60(– 3), 63(– 4) segments, excluding telson. Claws with long ventral filaments only, these often broken off, leaving short stumps instead. Vulvae as in Fig. 33 . Operculum longer than bursa, with two rows of setae on anterior face (6 – 8 setae, i.e. 3 – 4 in each row, in the vulvae examined). Apical margin of operculum with three low prominences, of which middle one either well-developed ( Fig. 34 ) or not ( Fig. 33 ). Lateral and mesal outgrowths at operculum’s apex varying from rounded ( Fig. 33 ) to acute ( Fig. 34 ). Variation in structure of vulva in one and the same individual not noted, Figures 33 and 34 showing vulvae of different specimens from the same sample D – 0 293. Bursa setose, with four setae both on lateral and mesal sclerites, six setae on each side of median plate of posterior sclerite.

Juvenile. Length not exceeding 9 – 10 mm, body with 9 – 10 apodous segments in front of telson.

Name. The specific epithet refers to the more numerous body segments as compared to that in A. oligosegmentatus sp. nov.

Remarks. Superficially, A. multiarticulatus sp. nov. is rather similar to A. oligosegmentatus sp. nov., but differs mainly by the slenderer body and more numerous segments. In most cases, males of A. multiarticulatus sp. nov. are longer than those of A. oligosegmentatus sp. nov. One could suggest that the slenderer body in the former species is attained due to its greater length. Yet this is not so. In these two species, males of the same or a similar length show different diameters: 0.9 – 1.1 mm in A. multiarticulatus sp. nov., versus 1.0– 1.3 mm in A. oligosegmentatus sp. nov. In addition, longitudinal stripes are far less distinct, up to virtually missing, on the dorsum of A. multiarticulatus sp. nov., with most of the specimens (except one) also showing more numerous apodous segments in front of the telson. This latter is evidence of further potential growth, meaning the animals would become still longer and attain more segments. In other words, this is a stable feature to securely distinguish both of these new species.

As regards gonopod structure, the main differences are observed in the structure of the promere apex: however variable and partly overlapping (= regularly convex) in shape, it is sometimes excavate in A. multiarticulatus sp. nov., but never so in A. oligosegmentatus sp. nov., ranging from regularly convex to excavate ( Figs 35–39 ) versus oval to regularly convex ( Figs 21–23 ), respectively. In addition, the shape of the promere in A. multiarticulatus sp. nov., is rather subquadrate, as opposed to subtriangular in A. oligosegmentatus sp. nov. The breadth of lamella al on the opisthomere somewhat differs as well. The vulvae are morphologically very similar and highly variable, offering no reliable features to distinguish these two species.

It is also noteworthy that, based both on opisthomere structure (al and ml breadths) and a vertical body diameter of 1.0 mm, males of A. oligosegmentatus sp. nov. from Hualien County approach closely those of A. multiarticulatus sp. nov. Yet the shapes of the promere, coupled with fewer body segments, i.e. 47(– 2), allow for a secure identification of these samples to be made as belonging to A. oligosegmentatus sp. nov. Molecular analyses would be indispensable to further clarify the identities of these two very similar species.

Figures

FIGURES 27 – 34. Anaulaciulus multiarticulatus sp. nov., male (27 – 32) and female (33 – 34) paratypes. 27, leg 1, front view; 28, leg 2 and penes; 29, promere, caudal view; 30, left opisthomere, caudal view; 31, left opisthomere, front view; 32, left opisthomere, lateral view; 33, right vulva of a smaller female from sample D – 0293, caudal view; 34, distal part of vulva of a larger female from sample D – 0293, caudal view; il, intermediate lamella of opisthomere; al, anterolateral lamella of opisthomere; ml, mesal lobe of opisthomere apex; fp, basal flap of opisthomere. Scale in mm.

FIGURES 35 – 39. Anaulaciulus multiarticulatus sp. nov., male paratypes. Variation in shape of promere apex: 35 – 36, different individuals from sample D – 0294, 37 – 39, different individuals from sample D – 0293. Scale in mm.

FIGURES 21 – 23. Anaulaciulus oligosegmentatus sp. nov., male paratypes. Variation in shape of promere apex: 21, individual from sample D – 0620, 22, individual from sample D – 0298, 23, individual from sample D – 0011. Scale in mm.