Seira maroccana, Negri, Ilaria, Pellecchia, Marco & Fanciulli, Pietro Paolo, 2005

Negri, Ilaria, Pellecchia, Marco & Fanciulli, Pietro Paolo, 2005, Two new species within the genus Seira Lubbock, 1869 from Morocco (Collembola, Entomobryidae), Zootaxa 840, pp. 1-12 : 6-11

Seira maroccana sp. n.

Sampling locality

Tadirhoust oasis, near Goulmima village, High Atlas , Morocco, 1400 m, Fig. 1 .

Types

Holotype and 5 paratypes are deposited in the collembolan collection of Prof. R. Dallai at the Department of Evolutionary Biology of the University of Siena, Italy.

Derivatio nominis

From the name of the country ( Morocco) where the new specie was found.

Description

Blue pigment is widely distributed over the body; also present on the legs reaching the femurs, absent from the tibiotarsi. Blue pigment also present on the manubrium and on the proximal part of the dens. The living specimens show three whitish­iridescent bands over a dark blue background ( Fig. 2 B): the first band is located between the abdominal tergites II and III, the second one covers the anterior part of Abd IV, the last one is on the anterior part of the abdominal tergite V. The same whitish iridescent effect is present laterally to the II and III thoracic segment and in the lateral and posterior part of the head ( Fig. 2 B). This colour pattern seems to be due to the different distribution and shape of the scales: in fact, in the whitish iridescent bands are hyaline and adherent to the cuticle, while on the rest of the body, showing a blue pigment, the scales are brown, with quadrangular shape and they never adhere to the sclerites. The whitish­iridescent effect disappears in the specimens preserved in liquid fixative, as already observed in others taxa by Gisin and da Gama (1962). Scales occur on the dorsal surface of Ant I and Ant II.

Body length 1,8–2 mm (measurements and ratios from the holotype). The total length of antennae is 820 m while the length of each single segment is: Ant I= 144 m, Ant II= 200 m, Ant III= 210 m and Ant IV= 270 m. The ratio between them is 1: 1,4: 1,46: 1,9. Ant IV with a single terminal vesicle ( Fig. 5 H). Antennal organ III is constituted by two sensory rods placed in a small cuticle fold ( Fig. 5 G). Cephalic diagonal 450 m and its ratio with antennal length is 1,82. Abdominal tergites III and IV are respectively 225 m and 585 m; their ratio is 2,6. Manubrium and dens­mucro are 360 m and 500 m respectively; apical part of dens and mucro as in Fig. 5 D. Retinaculum with 4 teeth and 1 macrochaeta on the corpus. The length of femur, tibiotarsus and claw of the third leg is 297 m, 385 m and 54 m respectively. Claw with 2 basal and 2 distal teeth ( Fig. 5 I). Empodial appendage lanceolate without basal tooth ( Fig. 5 I). Trochanteral organ with about 14 smooth setae ( Fig. 5 E). Eye patch with 8+8 pigmented ocelli. Labial chaetotaxy as in Fig. 5 F with formula M1M2REL1L2. Chaetotaxy of the labrum is 4,5,5,4; shape of the labral papillae as in Fig. 5 L. Ventral tube with about 24 setae, most of them are ciliated and only 4–5 are smooth ( Fig. 5 C). Ventral manubrial chaetotaxy with 4 anteapical setae ( Fig. 5 K); 3+3 setae bordering the ventral groove on the head ( Fig. 5 M).

Dorsal chaetotaxy of the head as in Fig. 5 B. The interocular region with 10 multilaterally ciliated macrochaetae. The frontal region has 5 macrochaetae. Inside the ocular plate there are 2 macrochaetae, while in its central­posterior part there are 4 macrochaetae (“Zone 3” according to Jacquemart, 1974); 2 additional setae are placed posterior to the ocular plate. The central region has 11 macrochaetae while in the occipital region there are 4 macrochaetae.

Body chaetotaxy as in Fig. 5 A. Thoracic tergite II contains a total of 25 macrochaetae on the dorsal region and 1 in the lateral position. The dorsal macrochaetae can be divided into three major zones ( Jacquemart, 1974). The first one (“Zone 1”) is further divided into two subgroups, “A” and “B”, each containing 3 and 4 macrochaetae. “Zone 2” has 4 L forming macrochaetae. “Zone 3” contains 14 macrochaetae which can be further subdivided into three subgroups, “A”, “B” and “C”, containing 6, 2 and 6 macrochaetae, respectively. Thoracic tergite III has 14 macrochaetae on the dorsal region and 1 in the lateral position; the dorsal ones have the following distribution: 6 (3 anterior + 3 posterior) in the “A” group, 4 in the “B” group and 4 in the “C” group. Abdominal tergites I, II and III contain 6(0), 4(1) and 1(3) dorsal macrochaetae, respectively (lateral macrochaetae in parentheses). Abdominal tergite IV has 11 macrochaetae which are placed into three rows; the anterior one contains 4 macrochaetae, 2+2 are placed in the central area while 3 are in the posterior row. Abd V with 15 macrochaetae. Distribution of pseudopores and botriotrichia as in Fig. 5 A.

Discussion

S. maroccana n. sp. belongs to the domestica species group. It is closely related to S. ferrarii Parona, 1888 with which it shares the same pattern of cephalic chaetotaxy, while it differs in the number of macrochaetae on the anterior row of the Abd IV: these are 4 in the new species and 5 in S. ferrarii . Pigmentation is also quite similar in these two species, even if different patterns were observed in some populations of S. ferrarii ( Stach 1967; Dallai & Ferrari 1970). The presence of 4 macrochaetae in the anterior row of the Abd IV could be considered a useful tool to recognize the new species, since most taxa of the domestica group have 5 macrochaetae ( Jacquemart 1974). Anyway, few other species show 4 macrochaetae in the same position, among these S. vanderheydeni Jacquemart, 1974 , S. faironi Jacquemart, 1974 , and S. algira Jacquemart, 1974 , but they differ from S. maroccana n. sp. by showing differences in the head and thoracic­abdominal chaetotaxy especially on the dorsal part of Th II. Patterns of dorsal chaetae similar to S. maroccana n. sp. were also found in S. nigeri Jacquemart, 1974 , S. agadesi Jacquemart, 1974 , and S. deserti Jacquemart, 1974 , even if these latter taxa have always 5 macrochaetae in the anterior row of the Abd IV, instead of 4 as in the new species. Furthermore, they show some differences in the cephalic chaetotaxy and both S. agadesi and S. nigeri are also unpigmented species. The new species is also similar to S. sanaaensis Barra 2004 from which it differs for the different number of macrochaetae on thorax II, the pattern of dorsal pigmentation and the morphology of the hind foot complex.

Besides S. maroccana n. sp., similar patterns of chaetotaxy and pigmentation are common to several taxa, many of which are from the Northern Africa, Black Sea, Western Europe and Mediterranean Basin. This fact should confirm the presence, in these regions, of some closely related species of Seira , among which only S. ferrarii shows a widespread distribution. We could suggest that these species had a common ancestor, which underwent multiple speciation events principally at the borderline of its distribution range, probably mediated by past climatic changes. This is only a working hypotheses, and further investigation are needed to clarify the puzzling situation.

TABLE I. Comparison of the number of dorsal macrochaetae in the Moroccan species of Seira . TII) dorsal macrochaetae in the posterior part of the thorax II; they are the macrochaetae of the zone 3 (A, B, C) according to Jacquemart (1974) and Christiansen and Bellinger (2000). TIII) macrochaetae of the thorax III (zone A, B and C in Jacquemart, 1974 and Christiansen and Bellinger, 2000). AI – AIV) dorsal macrochetae of the abdominal tergites. Lateral macrochaetae not considered. AIVant., AIVmed. and AIVpos) anterior, median and posterior part of the abdomen IV. 1) Thibaud

and Massoud, 1980; 2) Handschin, 1925; 3) Gers and Deharveng, 1985; 4) this paper.

Table I summarizes the main macrochaetal features useful for the recognition of the species of Seira from Morocco. However the number of the species could be larger than present; many other species of Seira have been found in the closer country ( Algeria and Tunisia) ( S. ferrarii , S. algira , S. debruyni , S. insalahi , S. deserti , S. vanderheydeni , S. lesnei , S. rosei , S. punica ) and the presence of some of them in Morocco might be hypothesized.

Figures

FIGURE 1. Map of sampling sites. 1) Seira atlantica sp. n. 2) Seira maroccana sp. n.

FIGURE 2. Micrographs of living specimens of Seira atlantica n. sp. (A) and Seira maroccana n. sp. (B).

FIGURE 5. Seira maroccana n. sp. A) dorsal chaetotaxy of the body showing macrochaetae (open circle), trichobotria (T) and pseudoporae (P); B) cephalic chaetotaxy; C) lateral view of the ventral tube; D) distal part of the dens and mucro; E) trochanteral organ; F) chaetotaxy of the labium; G) antennal organ III; H) apical vesicle of the Ant. IV; I) foot complex of the third leg, K) ventral manubrial chaetotaxy; L) shape of the labral papillae; M) setae bordering the ventral groove on the head.