Porcellio pseudornatus, Taiti & Rossano, 2015

Taiti, Stefano & Rossano, Claudia, 2015, Terrestrial isopods from the Oued Laou basin, north-eastern Morocco (Crustacea: Oniscidea), with descriptions of two new genera and seven new species, Journal of Natural History 49 (33), pp. 2067-2138 : 2107-2111

Porcellio pseudornatus sp. nov.

( Figures 23–25)

Material examined

Holotype: ♂, St. 5, under stones near beach, leg. S. Taiti and C. Rossano, 1 May 2004 ( MZUF 9510 ) . Paratypes: 7 ♂♂, 10 ♀♀, same data as holotype ( MZUF 9510 ) ; 1 ♂, 1 ♀, same data as holotype ( SMNS 15674 ) ; 1 ♂, 3 ♀♀, St. 2, under stones at base of cliff, leg. S. Taiti and C. Rossano, 1 May 2004 ( MZUF 9511 ) ; 1 ♀, St. 7, leg. S. Taiti, 29 April 2004 ( MZUF 9512 ) ; 2 ♂♂, 2 ♀♀, St. 9, under stones in meadow, leg. S. Taiti, 28 April 2004 ( MZUF 9513 ) ; 1 ♂, 1 ♀, St. 14, Phillyrea wood, leg. S. Taiti, 27 April 2004 ( MZUF 9514 ) ; 1 ♂, same locality, leg. S. Taiti and C. Rossano, 27 September 2005 ( MZUF 9515 ) ; 3 ♂♂, 1 ♀, St. 16, along road margin under stones, leg. S. Taiti, 28 April 2004 ( MZUF 9516 ) ; 2 ♀♀, St. 17, leg. S. Taiti, 29 April 2004 ( MZUF 9517 ) .

Other material examined

1 ♂, 1 ♀, Al Hoceima, near road under stones, leg. C. Rossano, 4 May 2004 ( MZUF 9518 ) .

Description

Maximum length: ♂, 22 mm; ♀, 23 mm. Body outline as in Figure 23A. Colour brown-grey with pale marginal parts of frontal lateral lobes and epimera of pereon and pleon; sometimes with two paramedian yellowish round spots on pereonites 5–7 and pleonites 2–4; antennae uniformly grey, pereopods and pleopod 1–2 exopods pale, pleopod 3–5 exopods dark. Dorsal surface of cephalon, pereon and pleon distinctly granulated with many scattered short triangular scale-setae ( Figure 22B); numerous gland pores in rounded fields disposed near the anterior corner of pereonite 1 and more or less in the middle of pereonites 2–7 close to the lateral margins of the segments ( Figure 22A, E); noduli laterales small, the ones on pereonites 1–4 inserted about twice more distant from the lateral margin than those on pereonites 5–7 ( Figure 23A). Cephalon ( Figure 22C, D) with no suprantennal line; large rounded lateral lobes obliquely bent downwards and distinctly protruding frontwards, median lobe widely rounded, often slightly incised at the apex; eye with about 30 ommatidia. Pereonites 1–3 with hind margin slightly concave at sides, more distinct on pereonite 1; pereonites 3–7 with posterior corners bent backwards and progressively more acute. Pleonites 3–5 with falciform epimera ( Figure 23A, F); tips of pleonite 5 epimera reaching 2/3 of telson length. Telson ( Figure 23F) about twice as wide as long with a triangular distal part. Antennule ( Figure 23G) with first article distinctly longer than second and third; third article with a tuft of short aesthetascs near the apex. Antenna ( Figure 23H) reaching back or slightly surpassing the posterior margin of pereonite 3; fifth article of peduncle shorter than flagellum; first flagellar article about twice as long as second. Mandibles ( Figure 24A, B) with molar penicil dichotomized and a line of eight free penicils. Maxillule ( Figure 24C) outer branch with 4 + 6 teeth, all simple; inner branch with a distinct posterior point and two long and thin penicils. Maxilla ( Figure 24D) bilobate with setose apex, inner lobe quadrangular, much smaller than outer one; two long setae on the margin between the two lobes. Maxilliped ( Figure 24E) endite with two small triangular setae on distal margin and no penicil; first article of palp with two strong setae. Pleopodal exopods 1 and 2 with monospiracular covered lungs ( Figure 25C, D). Uropod ( Figure 23A, F) with a triangular depression on protopodal outer margin, not visible in dorsal view.

Male: Uropodal exopods ( Figure 23F) flattened, elongated and much longer than in females (4 times as long as wide in males, less than 3 times in females). Merus and carpus of pereopod 1 ( Figure 25A) to 4 and, to a lesser extent, 5 with a brush of pointed setae. Pereopod 7 ( Figure 25B) ischium distally enlarged with a transversal depression and a setose area on rostral surface; sternal margin slightly convex; carpus with a large rounded lobe on distal half of tergal margin. Pleopod 1 ( Figure 25C) exopod with long medial lobe with parallel sides, oblique and sinuous distal margin with three strong setae at apex, and some short setae along the medial margin; endopod with distal part straight, rounded and setose apex. Pleopod 2 ( Figure 25D) exopod triangular and slightly shorter than endopod. Pleopod 3–5 exopods as in Figure 25E– G.

Etymology

From the stem of the Greek ‘Pseudes’ = false, erroneous + ornatus . The species name refers to the similarity with Porcellio ornatus Milne-Edwards , from south-eastern Spain.

Remarks

According to Vandel (1958a), four species of the Rif-Betic group of Porcellio occur in the Rif region: P. ornatus Milne-Edwards ; P. wagneri Brandt, 1841 ; P. hoffmannseggii Brandt, 1833 ; and P. echinatus Lucas, 1849 . The specimens here examined do not seem to belong to any of these four species, nor to any other species in this group, even if they are strictly related to P. ornatus and P. wagneri . Specimens of P. ornatus collected from the type locality in south-eastern Spain (many ♂♂ and ♀♀, Cartagena, Murcia, leg. M. Rizzotti Vlach, 4 August 1981, MZUF 9594) have been examined and are here illustrated ( Figures 26 and 27) for comparison with our specimens from the Oued Laou basin. Porcellio pseudornatus differs from P. ornatus in the dorsal body surface more granulated, wider dorsal scale-setae, posterior margin of pereonites 1–3 more concave at the sides, thinner antennae, much longer male uropodal exopods and more pronounced rounded lobe on the male pereopod 7 carpus. According to the figures provided by Lucas (1849, plate 6, Figures 6A– C); for P. wagneri originally described from Algeria, the new species differs in having the male uropodal exopods much wider (4 times as long as wide vs. 7.5 times in P. wagneri ). The material of P. ornatus and P. wagneri from the Rif studied by Vandel (1958a) needs to be re-examined to confirm that also these two species are present in the area.