Enghophyllum, Lazányi & Vagalinski, 2013

Lazányi, Eszter & Vagalinski, Boyan, 2013, A new genus of the millipede tribe Brachyiulini (Diplopoda: Julida: Julidae) from the Aegean region, European Journal of Taxonomy 70, pp. 1-12 : 2-4

Genus Enghophyllum gen. nov.

urn:lsid:zoobank.org:act:15008961-CD77-4325-B694-13BA1F7E514E

Type species

Brachyiulus (Chromatoiulus) naxius Verhoeff, 1901

Diagnosis

A genus of Brachyiulini , differing from contribal genera by the following combination of characters: promere broad, shield-like, in situ protruding mostly posteriad, completely covering opisthomere and gonopodal sinus; transverse muscles and coxal apodemes of the promere fully reduced. Opisthomere with 3 well-differentiated processes: lateral (lp), basal posterior (bpp) and apical posterior (app). Solenomere rather simple, tubular.

Etymology

This genus is named in honor of Prof. Henrik Enghoff from the ZMUC, not only for his vast contribution to our knowledge of diplopods, but also for his continuous encouragement and help during our work with Brachyiulini .

Description

Two frontal, four supralabral and 14-18 labral setae. Antennomeres 4 and 5 subequal in length ( Fig. 1A ). Gnathochilarium as on Fig. 1B . Metazona sparsely striated, as emphasised by Verhoeff (1901); ozopores right on the suture ( Fig. 1C ). Preanal process straight, anal valves sparsely pilose ( Fig. 1D ); subanal scale triangular, with protruding tip ( Fig. 1E ).

Males

Mandibular stipes slightly protruding ( Fig. 1 F-G). First leg-pair like simple, rounded, somewhat converging hooks; the two hooks converging in an obtuse angle ( Fig. 1H ). Second leg-pair ( Fig. 1I ) with two ventral pads: on postfemur (pf) and tibia (t). Penis ( Fig. 1J ) significantly small, deeply hidden in penis sac, with two very short lobes and two rounded small lamellae running parallel, i.e., not diverging (rl and ll for right and left lamella). Pleurotergum of the 7 th body ring protruding like a simple shovel (broken in the unique holotype of E. sifnium gen. et sp. nov., thus investigated only in E. naxium , see Fig. 1K ). Walking legs ( Fig. 1 L-M) with two ventral pads: on postfemur (pf) and tibia (t). Tarsus of midbody legs slightly longer than tibia: tarsus / tibia = (1.05-1.1) / 1.

Gonopods noticeably big compared to body size, directed mostly posteriad. Promere bevelled in laterobasal corner to fit into the inner curve of the 7 th body ring; latero-basal corner of promere only with thin triangular lamella (tl) ( Fig. 2 D-E). Promeres attached to each other in their meso-basal corner with a chitinous bridge. A short, oblique ridge (r) on posterior surface of promere ( Figs 2A , D-E, 4A, C). Flagellum emerging from a well-developed sinus (fsi) ( Fig. 2 D-E). At the level of this sinus a deepening on anterior surface of the promere (d) ( Fig. 4B ). Opisthomere entirely concealed under the promere, protruding postero-ventrad, the two promeres tightly closing the ventral opening on 7 th ring like a pair of shutters. Opisthomere not embedded in the groove formed by the oblique ridge on the promere’s posterior surface (unlike in Megaphyllum ), but “riding” on the ridge ( Figs 2A , 4C ): posterior basis of opisthomere with a characteristic riffle (ri) formed by chitinous lamellae, where the ridge of the promere is positioned ( Figs 2A, G , 4 C-D). Opisthomere with a well-developed lateral process (lp) and an apical and a basal posterior process (app and bpp). Solenomere (s) simple, with no processes but basally with a micro-spinose pillow (msp) ( Figs 2 A-C, F-G, 4A-D). Flagellum channel and sperm canal (fc and sc) each with an apical opening ( Fig. 4C ).

Females

The only available female of E. sifnium gen. et sp. nov. is in stadium IX (with 8 rows of ocelli) and proved to be subadult, but females of E. naxium in stadia VIII-IX (with 7-8 rows of ocelli) had fully developed vulvae, which we used here for the description of female sexual characters. First two legpairs slightly swollen.

Vulva ( Fig. 3 ): Subcylindric in shape, the mesal half shorter, the opening large, oval, apical. Operculum shorter than bursa, with around 20-25 setae. Mesal and lateral sclerites with 2-3 setae each. Apodematic tube not opening apically into a longitudinal median cleft as in, e.g., Megaphyllum species, but into a wide sinus (si). Around this sinus a thin wall, formed by the apical part of the bursa. These walls with small dot-like pores; most setae (around 20/side) emerging from this apical region. Apodematic tube (at) ending in two receptaculi seminis or ampullae. Central ampulla (ca) drop-like. Distal, globular ampulla (da) joining the apodematic tube through a twisted connecting tube (ct). Connecting tube very long, thus the distal ampulla hanging out of the bursa; easily broken off during preparation.

Remarks

The everted penes of the adult E. naxium male from Antiparos was quite soft, amorphous and huge, contrary to the stout, minute penes, deeply hidden under the 2 nd leg-pair coxae, observed in the E. naxium male from Mavri Islet and the E. sifnium gen. et sp. nov. male from Sifnos. It is possible that penes vary in size between copulating and non-copulating periods.

Figures

Fig. 1. Non-gonopod characters of Enghopyhllum gen. nov., males.A. Right antenna.B. Gnathochilarium. C. 8th and 9th body rings. D. Telson. E. Subanal scale. F. Mandibular stipital (“cheek”) lobe, lateral view. G. Mandibular stipital (“cheek”) lobe, ventro-lateral view. H. First leg-pair. I. Second leg-pair. J. Penis in the penis sac. K. Pleurotergum of the 7th body ring, ventral view. L. Anterior left leg on the 6th body ring. M. Anterior right leg on the 22nd body ring. – A-D, F, H-I, L-M: E. sifnium gen. et sp. nov., holotype. E: E. naxium, from Antiparos. G, J-K: E. naxium, from Mavri Islet.

Fig. 2. Gonopods of Enghophyllum sifnium gen. et sp. nov., holotype ♂. A. Left gonopods, mesal view. B. Leftgonopods,antero-lateralview.C.Leftgonopods,meso-posteriorview.D.Leftpromere,meso-posterior view. E. Left promere, postero-mesal view. F. Right opisthomere, lateral view. G. Right opisthomere, mesal view. – app = apical posterior process; bpp = basal posterior process; fc = flagellum channel; fl = flagellum; fsi = flagellum sinus; lp = lateral process; msp = micro-spinose pillow; P = promere; r = ridge; ri = riffle; s = solenomere; tl = triangular lamella. Scale bar: 0.2 mm.

Fig. 4. Gonopods of Enghophyllum naxium, male from Mavri Islet. A. Gonopods, posterior view. B. Gonopods, antero-lateral view. C. Right gonopods, mesal view. D. Left opisthomere, lateral view. – app = apical posterior process; bpp = basal posterior process; d = deepening; fc = flagellum channel; lp = lateral process; msp = micro-spinose pillow; P = promere; r = ridge; ri = riffle; s = solenomere; sc = sperm canal; tl = triangular lamella. Scale bar: 0.2 mm.

Fig. 3. Right vulva of Enghophyllum naxium, female from Antiparos Island, anterior view. – at = apodematic tube; ca = central ampulla; ct = connecting tube; da = distal ampulla; lv = lateral valve; op = operculum; si = sinus. Scale bar: 0.2 mm.