Alpioniscus (Illyrionethes) lossinii, Bedek & Gottstein & Taiti, 2019

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 : 489-491

Alpioniscus (Illyrionethes) lossinii n. sp.

( Figs 5–8 , 15 )

http://zoobank.org/ 47E3E7D2-262F-4D2C-B50E-3C3322043DC2

Alpioniscus strasseri . —Bedek et al. 2011: 278 (partim: Medvjeđa špilja).

Alpioniscus (Illyrionethes) sp. 2.— Bedek et al. 2019: figs 3, 5.

Material examined. Croatia, Croatian Littoral , Mali Lošinj Island: Holotype male Ćunski, Rt. Lokvica, Medvjeđa špilja (cave), 44.6055°N, 14.4079°E, 25–28 March 2010, leg. J. Bedek ( CBSSC IT4224 ).

Paratypes. 4 males, 1 male juv., 13 females, 3 juvs, same data as holotype ( CBSSC IT2397 ) ; 1 male, 8 females, same locality, 20 March 2005, leg. J. Bedek ( CBSSC IT2398 ) ; 2 males, 2 females, same locality and date, leg. M. Lukić ( MZUF 9846 ) ; 3 males, 5 females, same locality, 6 March 2010, leg. B. Jalžić ( CBSSC IT2400 ) ; 1 male, same locality, 2 March 2010, leg. J. Bedek ( CBSSC IT2402 ) .

Description. Maximum length: male, 4.9 mm; female, 5.3 mm. Colourless body, pereon with almost parallel sides, pleon narrower than pereon ( Fig. 5A,B ). Dorsum granulated, with ridges near posterior margins of cephalon, pereonites and pleonites 1–2, and some triangular scale-setae ( Fig. 5C ). Some gland pores on lateral margins of pleonites 4, 5 and telson ( Fig. 5E ).

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

Antennula ( Fig. 5F ) of three articles, distal article bearing five to seven aesthetascs. Antenna ( Fig. 5G ) with peduncle granulated; flagellum of eight to 10 articles with one row of aesthetascs on four to five different articles, always on a second and third article. Buccal pieces ( Fig. 6 ) as in A. magnus .

Pereopods similar in shape, ungual seta simple, dactylar seta bifid and setose ( Fig. 7A ).

Uropod ( Fig. 5E ) with protopod slightly grooved on outer margin; endopod distinctly shorter than exopod, proximally inserted.

Male: Pereopod 1 ( Fig. 7A ) carpus bearing five to six setae. Pereopod 1 and 2 with propodus and carpus bearing numerous short scales on rostral surface. Pereopods 5 and 6 with small lobe proximally on sternal margin. Pereopod 7 ( Fig. 7B,C ) ischium with straight sternal margin; merus with slightly concave sternal margin and proximally with small hookshaped lobe bearing up to five triangular scales and one large seta; carpus with straight sternal and tergal margins.

Genital papilla ( Fig. 8A ) with rounded apical part.

Pleopod 1 ( Fig. 8A ) exopod with distal part narrow and rounded apex, concave outer margin, slightly convex inner margin; endopod narrow, triangular, armed with long apical plumose seta.

Pleopod 2 ( Fig. 8B ) exopod subtriangular with slightly concave outer margin; endopod of two articles, slightly longer than exopod, distal article with posterior part narrower with strong and subapically bifid terminal seta.

Pleopod 3–5 exopods as in Fig. 8 C–E.

Etymology. The species is named after the island of Lošinj (Lat. Lossinium).

Remarks. The new species is characterized by the lack of a hump on the tergal margin of the male pereopod 7 carpus, together with A. (I.). haasi ( Verhoeff, 1931b) , A. (I.) heroldi ( Verhoeff, 1931a), A. (I.) herzegowinensis ( Verhoeff, 1931a) , A. (I.) kratochvili ( Frankenberger, 1938) , A. (I.) tuberculatus ( Frankenberger, 1939) , A. (I.) verhoeffi ( Strouhal, 1938) and the two new species described below, A. (I.) drazinai and A. (I.) mandalinae . It differs from all these species by the narrow distal part of the male pleopod 1 exopod; from A. (I.) heroldi and A. (I.) herzegowinensis also in the shape of the hook on the male pereopod 7 merus.

Figures

FIGURE 5. Alpioniscus (Illyrionethes) lossinii n. sp. A, B, paratype female CBSSC IT2379 from Medvjeđa špilja. C–G, para- type male CBSSC IT2379 from Medvjeđa špilja.A, habitus in dorsal view; B, pereonites and pleonites in lateral view; C, dorsal scale-seta; D, cephalon, dorsal; E, pleonites 4, 5, telson and uropods; F, antennula; G, antenna with enlargment of flagellum. Scale bars: A, B, D, E, G = 1 mm; C = 0.01 mm; F = 0.1 mm.

FIGURE 6. Alpioniscus (Illyrionethes) lossinii n. sp. Paratype male CBSSC IT2379 from Medvjeđa špilja. A, right mandible; B, left mandible; C, maxillula; D, maxilla; E, maxilliped. Scale bar: 0.1 mm.

FIGURE 7. Alpioniscus (Illyrionethes) lossinii n. sp. Paratype male CBSSC IT2379 from Medvjeđa špilja. A, pereopod 1 with enlargment of dactylus; B, pereopod 7 rostral view with enlargement of merus; C, pereopod 7 merus caudal view with enlargment of hook. Scale bars: A, B = 1 mm; C, = 0.1 mm.

FIGURE 8. Alpioniscus (Illyrionethes) lossinii n. sp. Paratype male CBSSC IT2379 from Medvjeđa špilja. 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.