Alpioniscus (Illyrionethes) drazinai n. sp.

(Figs 9–11, 15)

http://zoobank.org/ 80CE14BE-EE9C-4DD2-8978-3CFB267B4B0B

Alpioniscus (Illyrionethes) sp. 4.— Bedek et al. 2019: figs 3, 5.

Material examined. Croatia, Dalmatia, Dugi otok Island: Holotype male, Luka, Kamiškarta, Strašna peć (cave CCC HR00563), 44.0048°N, 15.0386°E, 29 July 2011, leg. J. Bedek (CBSSC IT4298).

Paratypes. 1 male, 14 females, sama data as holotype, (CBSSC IT2390); 1 male, same locality and date, leg. J. Bedek, T. Dražina (CBSSC IT2391); 1 male, 2 females, same locality, 11 October 2003, leg. J. Bedek (MZUF 9845); 1 male, 3 females, same locality and date, leg. B. Jalžić (CBSSC IT279); 4 females, 2 females juv., same locality, 30 September 2006, leg. H. Bilandžija (CBSSC IT4229); 1 male, Sali, Ćirova jama (cave), 43.9250°N, 15.1674°E, 9 May 2017, leg. K. Cindrić (CBSSC IT4207) ; 3 males, 5 females, 3 juvs, Sali, Jamnjak, Jama na Jamnjaku (cave), 43.9396°N, 15.1461°E, 5 May 2002, leg. A. Katalinić, T. Dražina, M. Lukić, J. Bedek, A. Sudar, H. Bilandžija, L. Katušić (CBSSC IT4234) ; 2 males, 2 females, 1 juv., same locality, 25 September 2017, leg. K. Cindrić (CBSSC IT4204); 2 males, 3 females, Sali, Čušćica, Jama u Čuščici (cave), 43.8990°N, 15.2121°E, 2 May 2002, leg. A. Katalinić, T. Dražina, M. Lukić, J. Bedek, A. Sudar, H. Bilandžija, L. Katušić (CBSSC IT4232) ; 1 male, 2 females, 1 juv., same locality, 9 May 2017, leg. L. Kauf (CBSSC IT4200); 1 male, 1 male juv., 2 females, 1 juv., same data (CBSSC IT4201); 1 male, same locality and date, leg. K. Cindrić (MZUF 9893); 2 males, 5 females, 1 juv., Žman, Slotnjak, Podslotnjak (cave), 43.9577°N, 15.1175°E, 29 September 2017, leg. T. Dražina (CBSSC IT4195) ; 1 male, 1 male juv., 3 females, same locality and date, leg. K. Cindrić (CBSSC IT4196); 2 males, 2 females, same locality, 11 May 2017, leg. T. Dražina (CBSSC IT4197); 1 female, same data (CBSSC IT4198); 1 male juv., 3 females, 2 juvs, same locality and date, leg. P. Novina (CBSSC IT4199).

Other material. Croatia, Dalmatia, Kornati archipelago, Piškera Island: 2 males, 1 male juv., 5 females, Blitvica (cave), 43.7652°N, 15.3526°E, 2 October 2017, leg. A. Kirin (CBSSC IT4141) ; 2 males, 1 female juv., same locality and date, leg. V. Sudar (CBSSC IT4144); 2 males, 3 females, same locality, 21 April 2018, leg. T. Rožman (CBSSC IT4249); 1 female, Petra Stijene (cave), 43.7662°N, 15.3485°E, 2 October 2017, leg. L. Ružanović (CBSSC IT4124) ; 4 males, 4 females, same locality, 21 April 2018, leg. T. Čuković, H. Cvitanović (CBSSC IT4236); 1 female, same locality and date, leg. T. Čuković (CBSSC IT4237); 1 male, 1 female, same locality and date, leg. H. Cvitanović (CBSSC IT4240); 1 male, 4 females, same locality, 19 April 2018, leg. H. Cvitanović (CBSSC IT4241); 1 male, 1 female, same locality and date, leg. T. Rožman (CBSSC IT4243) .

Description. Maximum length: male, 5.2 mm; female, 6.4 mm. Colourless body, pereon with almost parallel sides, pleon narrower than pereon (Fig. 9A). Back smooth to slightly granulated, with ridges near posterior margins of cephalon and pereonites 1–6 (Fig. 9A), and some triangular scale-setae (Fig. 9B). Some gland pores on lateral margins of pleonites 4 and 5, telson and uropodal protopods (Fig. 9D).

Cephalon (Fig. 9C) with suprantennal line bent down in middle; antennal lobes quadrangular, dorsally concave. Eyes absent. Posterior margin of pereonites 1, 2 convex, of pereonite 3 straight, and of pereonites 4–7 progressively more concave (Fig. 9A). Pleonites 3–5 with small posterior points visible in dorsal view (Fig. 9D). Distal part of telson with concave sides and rounded apex (Fig. 9D).

Antennula (Fig. 9E) of three articles, distal article flattened with five to eight aesthetascs. Antenna (Fig. 9F) with peduncle granulated; flagellum of eight to 10 articles with one row of aesthetascs on three to five different articles, always on second and third. Buccal pieces as in A. magnus .

Pereopods similar in shape, ungual seta simple, dactylar seta bifid and setose (Fig. 10A).

Uropod (Fig. 9D) with protopod slightly grooved on outer margin; endopod distinctly shorter than exopod, proximally inserted.

Male: Pereopod 1 (Fig. 10A) carpus bearing five to seven setae. Pereopod 1 and 2 with propodus and carpus bearing numerous short scales on rostral surface. Pereopods 4–6 merus with small lobe proximally on sternal margin. Pereopod 7 (Fig. 10B) ischium with straight sternal margin; merus with slightly concave sternal margin and large hook-shaped lobe bearing scales and one seta; carpus with straight sternal and tergal margins.

Genital papilla (Fig. 11A) with rounded apical part.

Pleopod 1 (Fig. 11A) exopod with thickset subquadrangular distal part, apex broadly rounded, sinuous outer margin, slightly convex inner margin; endopod triangular, narrow, armed with long apical plumose seta.

Pleopod 2 (Fig. 11B) exopod triangular with slightly concave outer margin and apical seta; endopod of two articles, distinctly longer than exopod, distal article with posterior part narrower with strong seta subapically bifid.

Pleopod 3–5 exopods as in A. lossinii .

Etymology. The new species is named after Dr. Tvrtko Dražina, team coordinator of the Dugi otok biospele- ological research.

Remarks. Alpioniscus drazinai n. sp. differs from all the other species lacking a tergal hump on the male pereopod 7 carpus by the subquadrangular distal part of the male pleopod 1 exopod and the large and protruding hook on the male pereopod 7 merus.