Porcellio brevicaudatus Brandt, 1833

Kashani, Ghasem M., Wägele, Johann-Wolfgang & Schmalfuss, Helmut, 2011, Redescription of Porcellio brevicaudatus Brandt, 1833 (Isopoda: Oniscidea); with some notes on other synonyms of Hemilepistus reaumurii (Milne-Edwards, 1840), Zootaxa 2924, pp. 63-67 : 64-67

Porcellio brevicaudatus Brandt, 1833

Porcellio brevicaudatus Brandt, 1833:180

Hemilepistus brevicaudaus Budde-Lund, 1885: 159 .— Brian, 1930: 446. Hemilepistus sottii Arcangeli, 1932: 7 .

Hemilepistus rostratus Arcangeli, 1932:9 .

Hemilepistus patrizii Brian, 1932: 330 .

Material examined. Male, lectotype, here designated, length 11 mm, Egypt, 1820–1824, leg. Ehrenberg & Hemprich (BMN 7079). Male, paralectotype, same data as for lectotype (BMN 7079).

Three males, syntypes of Hemilepistus sottii , Libya, Cirenaica, Guarscia, 4 April 1922, leg. Prof. Silvestri ( MRSNT Is-370).

Two males, syntypes of Hemilepistus sottii , Libya, Cirenaica, Zavia Mechili, leg. Dr. Festa ( MRSNT Is-370).

Female with marsupium, holotype of Hemilepistus patrizii , Algeria, “presso Zuetina”, 20 March 1931, leg.? ( MCSNG).

Diagnosis. Cephalothorax with well developed lateral and median lobes. Dorsal surface of cephalothorax and pereion-tergites with several rounded tubercles, more conspicuous on anterior parts. Pleotelson short, triangular, not surpassing uropodal protopodite. Pereiopods 1–2 with brushes of setae on the merus and carpus. Pleopodexopodite 1 subrectangular.

Redescription. Body elongated, about six times longer than cephalothorax width (fig. 1B). Body length up to 15 mm.

Cephalothorax with rounded lateral lobes and well-developed median lobe, tubercles in different sizes on dorsal part ( Fig. 1 A).

Antenna short, compared with other species of Porcellio , not surpassing second pereion-tergite, first flagellar article longer than the second ( Fig. 1 C).

Pereion-tergites with tubercles, well developed on the first pereionite and decreasing in size on posterior tergites, two marked larger tubercles on the median portion of each pereion-tergite ( Fig. 1 A).

Pleon narrower than pereion.

Telson triangular, almost 1.5 times as wide as long, with concave margins and rounded apex, not surpassing uropodal protopodite ( Fig. 1 B).

Pereiopods. Merus and carpus of male pereiopods 1–2 with brushes of trifid setae on sternal margin ( Fig. 1 D– E). Ischium of pereiopod 7 triangular with straight sternal margin ( Fig. 1 G).

Pleopod-exopodites 1–2 with large respiratory organs, which are lacking in the exopodites 3–5 ( Figs. 2 A, C). Pleopod-exopodite 1 subrectangular, with small median posterior lobe. Endopodite 1, see Fig. 2 B, pleopodexopodites 3–5 as in Fig. 2 E–G.

Remarks. This species differs from other species of Porcellio by possessing a very narrow body and convex postero-lateral margin of the first pereion-epimeron. Based on the shape of the first male pleopod-exopodite, it is a member of scaber -obsoletus -group. Regarding its geographical distribution, this species is the only species of scaber -obsoletus -group with a distribution range in northern Africa, which is otherwise populated by the laevis - hoffmannseggii -group (see Schmalfuss 1998).

Distribution. Egypt, Algeria, Libya.

Figures

FIGURE 1. Porcellio brevicaudatus, syntypes of Hemilepistus sottii, male from Libya, Zavia Mechili. A, cephalothorax and pereion-tergites 1 – 4; B, dorsal view; C, antenna; D, pereiopod 1; E, pereiopod 2; F, pereiopod 3; G, pereiopod 7. Scale = 2 mm for A and B; 0.5 mm for C – G.

FIGURE 2. Porcellio brevicaudatus, syntypes of Hemilepistus sottii. A – D, male from Libya, Guarscia. E – G, male from Libya, Zavia Mechili. A, pleopod 1 exopodite; B, pleopod 1 endopodite; C, pleopod 2 exopodite; D, pleopod 2 endopodite; E, pleopod 3 exopodite; F, pleopod 4 exopodite; G, pleopod 5 exopodite. Scale = 0.25 mm for A – D; 0.5 mm for E – G ..