Alpioniscus (Illyrionethes) busljetai, Bedek, Jana, Gottstein, Sanja & Taiti, Stefano, 2019

Bedek, Jana, Gottstein, Sanja & Taiti, Stefano, 2019, A new species of Alpioniscus (Illyrionethes) from the Dinaric Karst (Isopoda, Oniscidea, Trichoniscidae), Subterranean Biology 32, pp. 33-42 : 33

Alpioniscus (Illyrionethes) busljetai sp. nov. Figs 1 , 2 , 3 , 4 , 5 , 6

Alpioniscus sp. - Bregović et al. 2008: 109 [partim: Markova špilja].

Alpioniscus (Illyrionethes) sp. 3. - Bedek et al. in press: figs 3, 5.

Material examined.

Holotype: ♂ Croatia, Starigrad Paklenica, Seline, Markova špilja (cave), 44°16.79'N, 15°28.63'E, 30.IX.2008, D. Hmura leg., CBSSC IT4252. Paratypes: 1 ♂, 1 ♀, 1 juv., same data as holotype, CBSSC IT2407; 1 ♀, 1 juv., ibid., 5.VI.2006, H. Bilandžija leg., CBSSC IT560; 2 ♂♂, 1 ♀, ibid., 5.VI.2006, M. Pavlek leg., CBSSC IT561; 2 ♂♂, 2 ♀♀, ibid., 1.V.2010, A. Kirin leg., CBSSC IT2235; 1 ♂ juv., ibid., 1.V.2010, M. Lukić leg., CBSSC IT3975; 1 ♂ juv., ibid., 18.XII.2012, A. Komerički leg., CBSSC IT2881; 1 ♀, ibid., 18.III.2013, K. Miculinić leg., CBSSC IT3974; 1 ♂, 1 ♀, 1 juv., ibid., 20.V.2018, P. Bregović leg., MZUF 9894; 3 ♂♂, 4 ♀♀, ibid., 20.V.2018, N. Kuharić leg., CBSSC IT4250; 2 ♀♀, ibid., 20.V.2018, N. Kuharić leg., CBSSC IT4398; 2 ♀♀, ibid., 20.V.2018, I. Jaklinović leg., CBSSC IT4251; 2 ♀♀, 1 juv., ibid., 20.V.2018, M. Čuček leg., CBSSC IT4399; 2 ♂♂, 1 ♂ juv., 2 ♀♀, Croatia, Starigrad Paklenica, Špecina špajza (cave), 44°17.10'N, 15°27.46'E, 29.VI.2013, A. Komerički leg., CBSSC IT3960; 2 ♀♀, ibid., 29.VI.2013, T. Dražina leg., CBSSC IT3961; 1 ♂, 1 ♀, ibid., 29.VI.2013, T. Dražina leg., CBSSC IT3962.

Description.

Maximum length: ♂, 4.4 mm; ♀, 6.0 mm. Colourless body, pereon with almost parallel sides, pleon narrower than pereon ( Figs 1 , 2A ). Back smooth, with ridges near posterior margins of cephalon and pereonites, and some triangular scale-setae ( Fig. 2B ). Some gland pores on lateral margins of pleonites 4 and 5 ( Fig. 2D ). Eyes absent. Cephalon ( Fig. 2C ) with suprantennal line bent downwards; antennal lobes rounded. Posterior margin of pereonite 1 convex, of pereonites 2, 3 straight, and of pereonites 4-7 progressively more concave ( Fig. 2A ). Pleonites 3-5 with small posterior points visible in dorsal view ( Fig. 2D ). Distal part of telson with concave sides and broadly rounded apex ( Fig. 2D ). Antennula ( Fig. 2E ) of three articles, distal article flattened and bearing five to six aesthetascs. Antenna ( Fig. 2F ) with distal articles of peduncle granulated; flagellum of five to seven articles with one row of aesthetascs on two to four different articles, always on second and third. Mandibles ( Fig. 3A, B ) with one penicil in right and three in left; molar process with one penicil in right and none in left. Outer branch of maxillula ( Fig. 3C ) with 4+6 teeth, apically entire, and one slender stalk; inner branch with three penicils, outer and middle subequal, inner distinctly longer. Maxilla ( Fig. 3D ) with setose and bilobate apex, lobes subequal in width. Maxilliped ( Fig. 3E ) endite narrow, with large segmented apical penicil; palp distally with three rounded lobes, basal article with two small compound setae; basis with rounded outer lobe protruding posteriorly and covered with long setae on margin. Pereopods with large, bifid and setose dactylar seta ( Fig. 4A ). Uropod ( Fig. 2D ) with protopod slightly grooved on outer margin; endopod distinctly shorter than exopod, proximally inserted.

Male. Pereopod 1 ( Fig. 4A ) carpus bearing four to six setae. Pereopod 1 and 2 with propodus and carpus bearing numerous short scales on rostral surface. Pereopods 1-4 merus with sternal margin straight, pereopods 5, 6 merus with progressively more concave sternal margin and small lobe proximally. Pereopod 7 ( Fig. 4B ) ischium with straight sternal margin; merus with slightly concave sternal margin and small hook-shaped lobe in proximal part directed ventro-laterally and bearing one seta; carpus with straight sternal margin and shallow and long rounded tergal hump in proximal part. Genital papilla ( Fig. 5A ) with rounded apical part. Pleopod 1 ( Fig. 5A ) exopod with posterior apex broadly rounded, slightly concave outer margin, straight inner margin; endopod narrow with almost parallel sides, armed with long apical seta. Pleopod 2 ( Fig. 5B ) exopod triangular with concave outer margin; endopod of two articles, distinctly longer than exopod, posterior part narrower than anterior with strong bifid terminal seta. Pleopod 3-5 exopods as in Fig. 5 C–E .

Etymology.

The species is named after Dujo Bušljeta, the National park Paklenica ranger and Croatian Biospeleological Society field research guide within the Paklenica area.

Remarks.

Alpioniscus busljetai sp. nov. differs from Dinaric Illyrionethes species by the shallow and long rounded tergal hump of the male pereopod 7 carpus, similar to the one present only in A. trogirensis . It differs from A. trogirensis in the shape of the male pleopod 1 exopod, with broadly rounded posterior apex and slightly concave outer margin (narrowly rounded posterior apex and sinuous outer margin in A. trogirensis ). The shape of the male pleopod 1 exopod is similar to the one of A. tuberculatus (Frankenberger, 1939), from which it differs by the presence of the dorsal hump of the male pereopod 7 carpus and smooth habitus.

Figures

Figure 1. Alpioniscus (Illyrionethes) busljetai sp. nov. in situ in Markova spilja (by courtesy of Petra Kutlesa). Scale bar: 1 mm.

Figure 2. Alpioniscus (Illyrionethes) busljetai sp. nov. Paratype ♀ CBSSC IT 2235 from Markova spilja A habitus in dorsal view. Paratype ♂ CBSSC IT 2235 from Markova spilja B dorsal scale-seta C cephalon, dorsal D pleonites 4, 5, telson and uropods. Paratype ♂ CBSSC IT 4250 from Markova spilja E antennula F antenna with enlargement of flagellum. Scale bars: 1 mm (A, F), 0.1 mm (C-E), 0.01 mm (B).

Figure 3. Alpioniscus (Illyrionethes) busljetai sp. nov. Paratype ♂ CBSSC IT 2235 from Markova spilja A right mandible B left mandible C maxillula D maxilla E maxilliped. Scale bar: 0.1 mm.

Figure 4. Alpioniscus (Illyrionethes) busljetai sp. nov. Paratype ♂ IT 4250 from Markova spilja A pereopod 1 with enlargement of dactylus B pereopod 7 rostral view with enlargement of carpus and merus, and merus hook. Scale bars: 1 mm.

Figure 5. Alpioniscus (Illyrionethes) busljetai sp. nov. Paratype ♂ IT 4250 from Markova spilja A genital papilla and pleopod 1 B pleopod 2 with enlargement of endopod tip. Paratype ♂ CBSSC IT 2235 from Markova spilja C pleopod 3 exopod D pleopod 4 exopod E pleopod 5 exopod. Scale bar: 0.1 mm.

Figure 6. Distribution map of Alpioniscus (Illyrionethes) busljetai sp. nov.