Alpioniscus (Illyrionethes) magnus ( Frankenberger, 1938 )

Bedek, Jana, Gottstein, Sanja & Taiti, Stefano, 2019, Taxonomy of Alpioniscus (Illyrionethes): A. magnus and three new species from the Dinaric Karst (Isopoda: Oniscidea: Trichoniscidae), Zootaxa 4657 (3), pp. 483-502 : 484-489

Alpioniscus (Illyrionethes) magnus ( Frankenberger, 1938)

( Figs 1–4 , 15 )

Titanethes albus .— Wettstein 1914: 59–64.

Illyrionethes magnus Frankenberger 1938: 27 , 30–33, figs 3–7.— Strouhal 1939a: 7, 23.—1939b: 115, 127–128, fig. 1.—1939c: 17–18.—1939d: 17–18.—1940: 94; Frankenberger & Strouhal 1940: 449.

Alpioniscus (Illyrionethes) magnus .— Vandel 1946: 155.— Buturović 1957: 7–49, fig. 24.— Schmölzer 1965: 58, figs 218– 219.— Karaman 1966: 378.— Potočnik 1993: 85, 178.— Tabacaru 1996: 35.— Horvatović 2014: 173, 175, 223. — Bedek et al. 2019: figs 3, 5.

Alpioniscus magnus . — Vandel 1947: 271.— Potočnik 1989: 64.— Schmalfuss 2003: 14.— Bedek et al. 2006: 14, 92.— Jalžić et al. 2010: 20.—Bedek et al. 2011: 240, 273–275, fig. 15— Jalžić et al. 2013: 13, 30, 40, 2 figs (not numbered).

Alpioniscus . — Giachino et al. 2011: 360 [partim: Jama kod Matešića stana].

Material examined. Croatia, Dalmatia, Brač Island: Nerežišće, Podgažul, Bazgovača (cave CCC HR01146 ) , 43.3065°N, 16.6222°E, 1 female, 1 juv., 29 September 1996, leg. M. Franičević ( CBSSC IT1665 ) ; 5 males, 1 male juv., 3 females, 1 female juv., 4 August 2004, leg. R. Ozimec and B. Jalžić ( CBSSC IT1664 ; IT1667 ) ; 1 male juv., 26 October 2006, leg. R. Ozimec ( CBSSC IT1669 ) ; 2 males juv., 1 female, 1 juv., 22 October 2007, leg. J. Bedek ( CBSSC IT1666 ; IT1672 ) ; 2 females, 5 January 2009, leg. F. Kljaković Gašpić and M. Pavlek ( CBSSC IT1670 ; IT1671 ) ; 8 males, 9 females, 5 October 2009, leg. M. Lukić and M. Novokmet ( CBSSC IT2094 ; IT2095 ; IT2097 ) ; 3 males, 2 females, 3 females juv., 30 June 2017, leg. M. Pavlek and T. Rožman ( CBSSC IT4321 ; IT4322 ) .

Nerežišće, Neorić, Činjadra (cave CCC HR01149), 43.3398°N, 16.5994°E, 5 males, 1 female, 1 female juv., 5 August 2004, leg. R. Ozimec and B. Jalžić ( CBSSC IT4323 ; IT4325 ); 6 males, 2 males juv., 6 females, 22 October 2007, leg. M. Lukić and J. Bedek ( CBSSC IT1356 ; IT1357 ); 1 female juv., 3 juvs, 5 January 2009, leg. H. Bilandžija and B. Jalžić ( CBSSC IT1368 ; IT4326 ; IT4327 ); 6 males, 3 males juv., 12 females, 3 females juv., 1 July 2017, leg. M. Pavlek and T. Rožman ( CBSSC IT4328 ; IT4329 ) .

Nerežišće, Zvirine stope, Dobra jama (cave CCC HR01151), 43.3085°N, 16.5808°E, 6 males, 8 females, 3 females juv., 2 juv., 5 August 2004, leg. R. Ozimec, P. Rade and B. Jalžić ( CBSSC IT4365 ; IT4366 ; IT4367 ); 1 male, 1 female, 22 October 2007, leg. H. Bilandžija ( CBSSC IT4368 ) .

Gornji Humac, Grimač, Jama kod Matešića stana (cave), 43.3059°N, 16.7511°E, 1 male, 1 male juv., 5 females, 1 female juv., 4 juvs, 6 August 2004, leg. R. Ozimec and B. Jalžić ( CBSSC IT4351 ; IT4352 ); 3 males, 1 male juv., 3 females, 2 females juv., 1 juv., 25 October 2006, leg. H. Bilandžija ( CBSSC IT4353 ) ; 2 females, 2 juvs, 13 March 2011, leg. D. Hmura, A Čukušić and P. Kutleša ( CBSSC IT4354 ; IT4355 ; IT4356 ); 2 males, 1 male juv., 4 males juv., 1 female juv., 2 juvs, 14 March 2011, leg J. Bedek, M. Pavlek and A. Komerički ( CBSSC IT2394 ; IT4357 ; IT4358 ; IT4359 ) .

Sumartin, Podstražišće, Jama kod Podstražišća (cave), 3 males, 3 females, 3 August 2004, leg. R. Ozimec ( CBSSC IT4375 ) .

Pučišća, Jasenovo brdo, Jama na Jasenovom brdu (cave CCC HR00554), 43.3368°N, 16.7440°E, 2 males, 31 July 2003, leg. M. Dropulić ( CBSSC IT4376 ) .

Povlja, Jama u Kupinovac (cave), 1 male, 1 female, 24 February 2002, leg. M. Franičević ( CBSSC IT4377 ) .

Selca, Kale, Trgud, Jama u Lukeša docu (cave), 43.2858°N, 16.8411°E, 3 males, 1 male juv., 4 females, 1 female juv., 3 juvs, 20 July 2007, leg. R. Ozimec and B. Jalžić ( CBSSC IT2603 ; IT2606 ) .

Pučišća, Jama za Mahrincem (cave CCC HR00293), 43.3445°N, 16.7409°E, 2 males, 1 male juv., 6 females, 2 females juv., 5 August 2004, leg. B. Jalžić and R. Ozimec ( CBSSC IT4330 ; IT4331 ); 4 males, 1 male juv., 7 females, 24 October 2007, leg. J. Bedek, H. Bilandžija and M. Lukić ( CBSSC IT2281 ; IT2282 ; IT4332 ); 1 male, 1 male juv., 8 females, 2 juvs, 5. January 2009, leg. M. Pavlek and F. Kljaković Gašpić ( CBSSC IT4333 ; IT4334 ); 3 males, 4 males juv., 4 females, 1 female juv., 4 juvs, 12 March 2011, leg. A. Čukušić, N. Raguž and L. Đud ( CBSSC IT4335 ; IT4336 ; IT4339 ) .

Selca, Ješkalovica, Ješkalovica (cave CCC HR01130), 43.2999°N, 16.8393°E, 2 males, 3 females, 3 juvs, 4 January 2009, leg. M. Pavlek and F. Kljaković Gašpić ( CBSSC IT2608 ; IT2610 ); 1 male, 1 male juv., 1 juv., 21 February 2010, leg. P. Bregović ( CBSSC IT2611 ) ; 1 male juv., 3 females, 2 females juv., 5 juvs, 28 February 2010, leg. N. Raguž and P. Bregović ( CBSSC IT2612 ; IT2613 ); 4 females juv., 7 juvs, 12 March 2011, leg. P. Bregović, D. Hmura and P. Kutleša ( CBSSC IT2615 ; IT2617 ; IT2618 ) .

Postira, Dol, Dunaj, Kaptaža K-2 (water capping tunnels-cave), 43.3592°N, 16.6230°E, 2 males, 2 males juv., 1 female juv., 28 February 2010, leg. B. Jalžić, H. Bilandžija ( CBSSC IT4361 ) ; 1 male, 3 males juv., 4 females, 6 females juv., 8 juvs, 12 March 2011, leg. A. Komerički and J. Bedek ( CBSSC IT4362 ; IT4363 ; IT4364 ) .

Postira, Škrip, Minjera (mine-cave CCC HR02009), 43.3613°N, 16.6063°E, 5 males, 2 females, 1 juv., 24 October 2007, leg. H. Bilandžija, J. Bedek and B. Jalžić ( CBSSC IT2283 ; IT2284 ; IT4342 ); 1 male, 3 males juv., 4 females, 1 female juv., 26 juvs, 13 March 2011, leg. J. Bedek, A. Komerički, N. Raguž, M. Pavlek and L. Đud ( CBSSC IT2392 ; IT2393 ; IT4343; IT4344; IT4345; IT4347 ; IT4349 ); 1 male, 1 female juv., 23 March 2018, leg. B. Jalžić ( CBSSC IT4350 ) .

Nerežišće, Drašnice, Spuža (cave), 43.3065°N, 16.6222°E, 1 male, 4 females juv., 3 juvs, 23 March 2018, leg. B. Jalžić ( CBSSC IT4372 ) .

Supetar, Tanki ratac (cave), 43.360229°N, 16.569356°E, 1 female, 1 juv., 29 June 2017, leg. T. Rožman ( CBSSC IT4340 ) .

Selca, Osridke, Žejava (cave CCC HR01147), 43.2846°N, 16.8040°E, 2 males, 1 female, 6 females juv., 10 juvs, 23 October 2007, leg. H. Bilandžija ( CBSSC IT4369 ; IT4370 ) .

Type locality. Croatia, Dalmatia , Brač Island : Nerežišće , Podgažul , Bazgovača (cave CCC HR01146 ); Supe- tar, Donji Humac , Kopačina (cave); Supetar , Tanki ratac (cave); Nerežišće , Neorić , Činjadra (cave CCC HR01149 ); Nerežišće , Filipovića jama (cave); Pučišća , Jama za Mahrincem (cave CCC HR00293 ); Pučišća, Spilja pod Vrhom (unknown cave) ( Frankenberger 1938) .

Redescription. Maximum length: male, 10.2 mm; female, 11.2 mm. Colourless body, pereon with almost parallel sides, pleon narrower than pereon ( Fig. 1A ). Dorsum smooth, with some triangular scale-setae ( Fig. 1B ). Some gland pores on lateral margins of pleonites 4, 5, telson and uropodal protopods ( Fig. 1D ).

Cephalon ( Fig. 1C ) with suprantennal line bent downwards in middle; antennal lobes quadrangular. Eyes absent. Posterior margin of pereonite 1 convex, of pereonites 2, 3 straight, and of pereonites 4–7 progressively more concave. Pleonites 3–5 with small posterior points visible in dorsal view. Distal part of telson with concave sides and broadly rounded apex ( Fig. 1D ).

Antennula ( Fig. 1E ) of three articles, distal article flattened and bearing five to 11 aesthetascs on apical margin. Antenna ( Fig. 1F ) smooth; flagellum of eight to 12 articles with one row of aesthetascs on four to six different articles, always on second and third.

Mandibles ( Fig. 2A, B ) with one penicil in right and three penicils in left; molar process with one penicil in right.

Maxillula ( Fig. 2C ) outer branch with 5+6 teeth, apically entire, and two slender stalks; inner branch with three penicils, outer and middle subequal, inner distinctly longer. Maxilla ( Fig. 2D ) with setose and bilobate apex, inner lobe distinctly wider than outer one.

Maxilliped ( Fig. 2E ) 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 similar in shape, ungual seta simple, dactylar seta bifid and setose ( Fig. 3A ).

Uropod ( Fig. 1D ) with protopod slightly grooved on outer margin; endopod distinctly shorter than exopod, proximally inserted.

Male: Pereopod 1 ( Fig. 3A ) carpus bearing six to seven setae. Pereopod 1 and 2 with propodus and carpus bearing numerous short scales on rostral surface. Merus of pereopods 1–3 with sternal margin straight, of pereopods 4–6 slightly concave with small lobe proximally. Pereopod 7 ( Fig. 3B, C ) ischium with straight sternal margin; merus with slightly concave sternal margin and hook-shaped lobe proximally, with scales and one seta at apex; carpus with dorsal hump on tergal margin, carpus length: top hump position 1.69±0.11 (N=10), carpus length: ending hump position 1.24±0.04 (N=10).

Genital papilla ( Fig. 4A ) with rounded apical part.

Pleopod 1 ( Fig. 4A ) exopod triangular with acute apex, inner and outer margins slightly sinuous; endopod narrow with wide basal part and concave outer margin, with apical seta distinctly shorter than basal article.

Pleopod 2 ( Fig. 4B ) exopod triangular with setae on outer margin; endopod of two articles, slightly longer than exopod, distal article progressively narrower towards apex with strong bifid terminal seta.

Pleopod 3–5 exopods as in Fig. 4 C–E.

Remarks. Alpioniscus magnus is one of the largest species of Dinaric Illyrionethes . It is characterized by the presence of a hump on the male pereopod 7 carpus, together with strasseri- lineage species (A. (I.). strasseri ( Verhoeff, 1927) , A. (I.). balthasari ( Frankenberger, 1937) , A. (I.). christiani Poto nik, 1983, A. (I.). iapodicus Bedek, Horvatović and Karaman, 2017 , A. hirci Bedek & Taiti, 2019 , A. velebiticus Bedek č & Taiti, 2019), and A. (I.) absoloni ( Strouhal, 1939a)) . It differs from all these species in having a low and long tergal hump on the male pereopod 7 carpus, the male pleopod 1 exopod with acute, instead of rounded apex and slightly sinuous outer margin. This species is amphibious.

Figures

FIGURE 1. Alpioniscus (Illyrionethes) magnus (Frankenberger, 1938). A, topotype female CBSSC IT1664 from Bazgovača. B–F, topotype male CBSSC IT1664 from Bazgovača. A, habitus, dorsal view; B, dorsal scale-seta; C, cephalon, dorsal view; D, pleonites 4, 5, telson and uropods; E, antennula; F, antenna with enlargment of flagellum. Scale bars: A, C, D, F = 1 mm; B = 0.01 mm; E = 0.1 mm.

FIGURE 2. Alpioniscus (Illyrionethes) magnus (Frankenberger, 1938). Topotype male CBSSC IT1664 from Bazgovača. A, right mandible; B, left mandible; C, maxillula; D, maxilla; E, maxilliped. Scale bars: 0.1 mm.

FIGURE 3. Alpioniscus (Illyrionethes) magnus (Frankenberger, 1938). Topotype male CBSSC IT1664 from Bazgovača. A, pereopod 1 with enlargment of dactylus; B, pereopod 7 rostral view with enlargement of merus and carpus; C, pereopod 7 merus caudal view with enlargment of hook. Scale bars: A, B = 1 mm; C = 0.1 mm.

FIGURE 4. Alpioniscus (Illyrionethes) magnus (Frankenberger, 1938). Topotype male CBSSC IT1664 from Bazgovača. A, genital papilla and pleopod 1; B, pleopod 2 with enlargement of endopod tip; C, pleopod 3 exopod; D, pleopod 4 exopod; E, pleopod 5 exopod. Scale bar: 0.1 mm.

FIGURE 15. Distribution map of analysed specimens of the Alpioniscus species, magnus-lineage in Croatia.