Terrestrial isopods from the Oued Laou basin, north-eastern Morocco (Crustacea: Oniscidea), with descriptions of two new genera and seven new species
Author
Taiti, Stefano
Istituto per lo Studio degli Ecosistemi, Consiglio Nazionale delle Ricerche, Florence, Italy;
Author
Rossano, Claudia
Dipartimento di Biologia, University of Florence, Florence, Italy
text
Journal of Natural History
2015
2015-02-28
49
33
2067
2138
journal article
21136
10.1080/00222933.2015.1009512
c5336d61-ecae-4eb6-8592-60f43e587af8
1464-5262
3999869
DCBF3103-1463-4A32-9BC0-A4CFE8B762AE
Soteriscus gibbosus
sp. nov.
(
Figures 18–20
)
Material examined
Holotype
:
♂
,
St.
14,
Phillyrea
wood, leg.
S. Taiti
,
27 April 2004
(
MZUF 9504
)
.
Paratypes
:
3 ♂♂
,
11 ♀♀
, same data as holotype (
MZUF 9504
)
;
1 ♂
,
6 ♀♀
, same locality, leg.
S. Taiti
and
C. Rossano
,
27 September 2005
(
MZUF 9505
)
;
1 ♀
, St. 10, leg.
S. Taiti
and
C. Rossano
,
26 April 2004
(
MZUF 9506
)
;
1♀
, St. 12, leg.
C. Rossano
,
26 April 2004
(
MZUF 9507
)
;
1 ♀
, St. 20, under stones along path to waterfall, leg.
S. Taiti
and
C. Rossano
,
2 May 2004
(
MZUF 9508
)
.
Description
Maximum length:
♂
,
11 mm
;
♀
,
15 mm
. Body outline as in
Figure 18A
. Brown colour with numerous yellowish muscle spots; a round pale spot at the base of pereon epimera in the frontal half of the segment; an elongated pale spot in the middle of pereonites and second or third to fifth pleonite; males darker than females. Back smooth with some scattered pointed scale-setae (
Figure 18B
); a distinct sulcus marginalis at the sides of pereon epimera with numerous gland pores along its whole length (
Figure 18G
); numerous gland pores scattered on the whole dorsal surface of the body; noduli laterales clearly visible, more or less at the same distance from the lateral margin of the pereonites, b/c and d/c co-ordinates as in
Figure 18C
. Cephalon (
Figure 18D–F
) with no suprantennal line, frontal line straight; very small lateral lobes bent downwards and not protruding frontwards; eye with about 25 ommatidia. Pereonites 1–3 with posterior margin regularly convex; pereonite 4 with posterior margin straight; pereonites 5–7 with posterior corners pointing backwards. Pleonites 3–5 with distinct but short posterior points (
Figure 18H
). Telson triangular with distinctly concave sides (
Figure 18H
). Antennule (
Figure 18I
) with first article longer than second and third; third article with a tuft of elongated aesthetascs at apex. Antenna (
Figure 19A
) reaching back the posterior margin of pereonite 3; fifth article of peduncle slightly curved, as long as flagellum; first flagellar article about 1.6 as long as second. Mandibles (
Figure 19B, C
) with molar penicil dichotomized and a line of several free penicils. Maxillule outer branch with 4 + 6 teeth (3 slightly cleft); inner branch with a distinct posterior point and two long and thin penicils (
Figure 19D
). Maxilla (
Figure 19E
) bilobate with setose apex, inner lobe quadrangular, much smaller than outer one; two long setae on the margin between the two lobes. Maxilliped (
Figure 19F
) endite with two small triangular setae on distal margin and no penicil; first article of palp with two strong setae. Pleopod 1 and 2 exopods with monospiracular covered lungs. Uropod (
Figure 18H
) with a triangular depression on protopodal outer margin; exopod almost twice as long as endopod; endopod proximally inserted.
Figure 18.
Soteriscus gibbosus
sp. nov.
from St. 14, paratype ♀: (A) adult specimen, dorsal view; (B) dorsal scale-seta; (C) co-ordinates of noduli laterals; (D) cephalon, dorsal view; (E) cephalon, frontal view; (F) cephalon and pereonite 1, lateral view; (G) pereonite 7, right side; (H) pleonites 4, 5, telson and uropods; (I) antennule.
Figure 19.
Soteriscus gibbosus
sp. nov.
from St. 14, paratype ♂: (A) antenna. Paratype ♀: (B) left mandible; (C) right mandible; (D) maxillule; (E) maxilla; (F) maxilliped; (G) uropod, lateral view.
Figure 20.
Soteriscus gibbosus
sp. nov.
from St. 14, paratype ♂: (A) pereopod 1; (B) pereopod 7; (C) genital papilla and pleopod 1; (D) pleopod 2; (E) pleopod 3 exopod; (F) pleopod 4 exopod; (G) pleopod 5 exopod.
Male: Carpus of pereopod 1 (
Figure 20A
) to 3 with a brush of pointed setae increasing in length distally. Pereopod 7 (
Figure 20B
) ischium with straight sternal margin and a longitudinal depression in the middle of the rostral surface; merus with a distinct hump on the posterior half of tergal margin. Pleopod 1 (
Figure 20C
) exopod with large medial lobe about twice as long as wide, with largely rounded apex bearing a line of short setae; endopod with distal part with almost parallel sides and a tuft of short setae at apex. Pleopod 2 (
Figure 20D
) endopod slightly longer than exopod. Pleopod 3–5 exopods as in
Figure 20E–G
.
Etymology
From the Latin ‘
gibbosus
’ = having a hump. The name refers to the male pereopod 7 merus which shows a distinct hump on the posterior half of tergal margin.
Remarks
At present the genus
Soteriscus
includes 15 species from Atlantic islands (Madeira Archipelago, Canary Islands and
Cape Verde
), northern
Morocco
, northern
Algeria
and southern
Spain
(
Schmalfuss 2003
). Three species have been recorded in northeastern Africa (
Vandel 1956b
,
1958
a
, 1960b):
S. gaditanus
,
S. virescens
(
Budde-Lund, 1885
)
and
S. fuscovariegatus
(
Lucas, 1849
)
. Of these species, only
S. gaditanus
was recorded from the Rif region (
Vandel 1956b
,
1958a
;
Achouri et al. 2008a
,
2008c
), but this species has not been collected by us. Re-examination of the material identified as
S. gaditanus
from the Rif region is necessary to confirm its occurrence.
Soteriscus gibbosus
differs from all the other species in the genus in having a distinct hump on the male pereopod 7 merus. In having the male pleopod 1 exopod with a large medial lobe, the news species shows affinities with
S. gaditanus
and
S.
fuscovariegatus
,
but in both these two species the medial lobe is distinctly more slender. It also differs from the former in having a broadly rounded instead of triangular apical part of the medial lobe of the male pleopod 1 exopod (see
Figure 2B
in
Vandel 1956b
), and in the thicker and shorter uropodal exopods (see
Figure 2A
in
Vandel 1956b
); from the latter in having shorter frontal lateral lobes and longer and more slender uropodal exopods (see
Figure 3A, B
in
Vandel 1956b
).