Noteremus infimus Mesibov, 2009

Mesibov, Robert, 2009, A new millipede genus and a new species of Asphalidesmus Silvestri, 1910 (Diplopoda, Polydesmida, Dalodesmidea) from southern Tasmania, Australia, ZooKeys 7 (7), pp. 55-74 : 64-67

Noteremus infimus Mesibov , sp. n.

urn:lsid:zoobank.org:act:3F1CD34C-A9E3-46C2-8269-C0AB7E8CC9F9

Figs.1B , 2B , 3C , 3D , 4B , 4E , 5C , 5D , map Fig. 9 .

Holotype. Male. Australia, Tasmania, Junee-Florentine karst, Khazad Dum (cave), 42º43’S 146º34’E ± 1 km, 25 March 1990, R. Eberhard, field no. JF4, ‘silt bank near stream, dark wetway pitches’, QVM 23 :46557.

Paratypes. 2 males, 2 females, 1 stadium VI female, details as for holotype, QVM 23 :12969 ; 2 males, 5 females, same details but 27 June 1989, S. Eberhard, field no. JF4-29, ‘more common in deep, near stream’, QVM 23 :12339 .

Material examined. All collected by S. Eberhard in the Junee-Florentine karst: 2 males, 1 female, Cauldron Pot (cave), 42º43’S 146º35’E ± 1 km, 9 July 1989, field no. JF2-2, deep, beyond Au Cheval, QVM 23 :12127 ; 3 females, same details but 15 July 1989, JF2-9, deep, beyond Au Cheval , QVM 23 :12116 ; 1 male, 1 female, 1 stadium VI male, same details but 28 January 1990, JF-2, streamway, QVM 23 :12951 ; 1 female, same details but 2 April 1990, JF-2, deep, QVM 23 :12955 ; 1 female, Growling Swallet (cave), 42º41’S 146º30’E ± 1 km, 1984, JF36-18, QVM 23 :12107 ; 1 male, 1 female, same details but 16 February 1985, JF36-25, QVM 23 :12095 ; 1 male, 1 female, same details but 14 April 1985, JF36-27, QVM 23 :12105 ; 1 male, same details but 2 June 1985, JF36-40, New Feeling passage, QVM 23 :12118 ; 1 female, same details but 13 April 1990, JF36, mainstream, QVM 23 :13498 ; 2 males, 1 stadium VI female, Porcupine Pot (cave), 42º40’S 146º30’E ± 1 km, 3 November 1985, JF387-1, deep, QVM 23 :12156 ; 5 males, 1 female, same details but 10 November 1985, JF387-2, deep, QVM 23 :12134 ; 2 males, Niggly Cave , 42º42’S 146º31’E ± 1 km, 28 April 1990, JF237-2, QVM 23 :12094 ; 1 female, same details but JF237, cracks, QVM 23 :13272 ; 1 female, Rift Cave , 42º43’S 146º35’E ± 1 km, 4 January 1985, JF34-4, QVM 23 :12163 ; 2 males, 2 females, same details but 12 June 1988, JF34-7, near intermittent stream, deep (- 150m), QVM 23 :12161 ; 1 stadium VI male, Burning Down the House (cave), 42º39’S 146º29’E ± 1 km, 11 September 1988, JF402-2, ‘common through cave’, QVM 23 :12181 ; 2 males, 2 females, Gormenghast (cave), 42º41’S 146º30’E ± 1 km, 19 November 1989, JF35-3, deep, QVM 23 :12336 ; 1 male, 5 females, Junee Cave , 42º44’S 146º36’E ± 1 km, 22 October 1989, JF8-3, ‘common beside stream, on rocks and mudbanks’, QVM 23 :12119 ; 1 male, 1 female, 2 stadium VI females, Owl Pot (cave), 42º40’S 146º30’E ± 1 km, September 1983, JF221- 4, 60-200m deep, QVM 23 :12121 ; 2 females, Pendant Pot (cave), 42º41’S 146º30’E ± 1 km, April 1984, JF37-6, QVM 23 :12335 ; 1 female, Serendipity (cave), 42º42’S 146º30’E ± 1 km, 12 January 1985, JF344-4, QVM 23 :12164 ; 1 female, Tassy Pot (cave), 42º40’S 146º30’E ± 1 km, September 1983, JF223-5, deep, - 200m, QVM 23 :12157 ; 1 female, 1 stadium VI male, Th e Chairman (cave), 42º43’S 146º36’E ± 1 km, 26 June 1988, JF99-2, deep, ‘near perennial or intermittent streams’, QVM 23 :12111 ; 1 female, Troll Hole (cave), 42º44’S 146º35’E ± 1 km, 7 October 1989, JFx1-3, deep ‘terminal RF Ch, -87m’, QVM 23 :12162 ; 1 female, Voltera (cave), 42º43’S 146º32’E ± 1 km, 12 November 1989, JF207-1, ‘at bottom (- 25m) in crack between rock and sediment’, QVM 23 :12115 ; 1 stadium IV female, Wherrets Cave , 42º42’S 146º32’E ± 1 km, 3 December 1989, JF-x6-4, deep, ‘base of aven’, QVM 23 :12333 .

Diagnosis. Small (to ca 12 mm), unpigmented, cavernicolous; midbody ring length to prozonite width 1.1-1.3; gonopod telopodite with one subterminal group of pointed, rod-like structures on posterior surface near apex vs. two groups in N. summus .

Description. As for N. summus , with differences as follows. Male/female approximate measurements: length 12/ 13 mm, maximum diameter 0.9/1.1 mm, maximum width across paranota 1.2/1.4 mm. Body unpigmented.

Male with head densely setose ( Fig. 4E ); antennal sockets moderately impressed, separated by ca 2X socket diameter. Antenna ( Fig. 2B ) slender; antennomere 6 widest; relative antennomere lengths (6,2,3)>5>4. Overall widths of rings 2-4 about equal, increasing slightly from 5 to 7, 8-16 more or less equal, 17 narrower. Ratio of ring length to prozonite width in midbody rings 1.1-1.3 ( Figs 3C, 3D ). Three transverse rows of short setae on metatergite. Paranota on rings 2-4 relatively wide, margins with three broad teeth, each bearing a stout seta. Ozopore small, round, opening laterally just ventral to short eminence at about half ring height close to posterior paranotal corner. Sternites very sparsely setose. Hypoproct broadly convex. Anterior legs ( Fig. 2B ) not swollen, prefemur slightly expanded dorsally, claw large; relative podomere lengths (tarsus, femur)>prefemur>(postfemur, tibia). Long, tapered setae in place of brush setae on prefemur, femur, postfemur, tibia.

Gonopod telopodite ( Figs 5C, 5D ) with distal row of pointed, rod-like structures extending to lateral surface of apex, and one small posterior cluster just below apex.

Distribution and habitat. Common in caves in the Junee-Florentine karst northwest of Maydena in south central Tasmania ( Fig. 9 ), to at least 200 m depth.

Etymology. Latin infimus (‘lowest’), adjective, nominative singular, for its occurrence deep below ground in caves.

Remarks. N. infimus is troglomorphic in lacking pigment, and in having more and longer setae, and more slender rings, legs and antennae than its surface-dwelling congener N. summus . A troglobitic polydesmidan from the Cape Range in Western Australia, Stygiochiropus communis Humphreys & Shear, 1993 (Paradoxosomatidae) , has been shown to vary considerably from cave to cave in details of gonopod form ( Humphreys and Shear 1993). In contrast, there is almost no gonopod variation from cave to cave in N. infimus . However, populations vary across the Junee-Florentine karst in the degree to which the trunk and legs are attenuated. Growling Swallet cave has the most troglomorphic specimens, with midbody ring length ca 1.3 X prozonite width. In both males and females from Growling Swallet the lower edge of the labrum is extended ventrolaterally on either side as a rounded tab of unknown function ( Fig. 4E ).

N. infimus is the only troglobitic millipede so far known from the Junee-Florentine karst. The surface-dwelling polydesmidans Paredrodesmus bicalcar , Tasmanodesmus hardyi Chamberlin, 1920 and an undescribed Tasmaniosoma species have also been found in Junee-Florentine caves, but only close to the surface (QVM specimen records).

Although the forests of the Florentine Valley have been repeatedly sampled for millipedes, no surface-dwelling Noteremus species has so far been found there. The disjunction between N. infimus and N. summus is 30-40 km.

Figures

Figure 1. (A) Noteremus summus sp. n., paratype female, QVM 23:46549; (B) N. infimus sp. n., paratype female, QVM 23:12339. (C), (D) Asphalidesmus golovatchi sp. n.: (C) Partly curled paratype male, QVM 23:46402; (D) anterior view of ring 6, paratype male, QVM 23:46560. Scale bars: (A), (B) = 2.5 mm, (C) = 1.0 mm, (D) = 0.5 mm.

Figure 2. Antenna and leg 6 of paratype males. (A) Noteremus summus sp. n., QVM 23:46549; (B) N. infimus sp. n., QVM 23:12339; (C) Asphalidesmus golovatchi sp. n., QVM 23:46560. Scale bars: (A), (B) = 0.5 mm, (C) = 0.1 mm. Setae and antennal cones not shown.

Figure 3. Dorsal view of ring 12 and left lateral view of ring 13 of paratype males. (A), (B) Noteremus summus sp. n., QVM 23:46556; (C), (D) N. infimus sp. n., QVM 23:12969. Scale bars = 0.5 mm.

Figure 4. (A)-(D) Spinnerets, posterior view. (A) Noteremus summus sp. n., paratype male, QVM 23:46556; (B) N. infimus sp. n., paratype male, QVM 23:12969; (C) Paredrodesmus taurulus, male, QVM 23:46313; (D) Procophorella innupta, male, QVM 23:25456. (E) N. infimus sp. n., head of male from Growling Swallet cave, QVM 23:12118. (F) N. summus sp. n., paratype male, QVM 23:46556, posterior view of ring 5 showing legpair 5 bases (foreground) and legpair 4 bases (background). Scale bars: (A)-(D) = 0.05 mm; (E), (F) = 0.25 mm.

Figure 5. Gonopods of paratype males in situ; lower images are enlargements of upper images. (A), (B) Noteremus summus sp. n., QVM 23:46556; (C), (D) N. infimus sp. n., QVM 23:12969. Scale bars: (A), (C) = 0.5 mm; (B), (D) = 0.1 mm.

Figure 9. Localities as of 1 January 2009 for Noteremus summus sp. n. (Ɨ), N. infimus sp. n. (·) and Asphalidesmus golovatchi sp. n. (Δ). Scale bar = 25 km; grey lines are 100 m elevation contours. Town abbreviations: M = Maydena, G = Geeveston, S = Southport. Inset: map of Tasmania showing location of main map (rectangle).