Salina zhangi sp. nov. Bellini & Cipola

Figs 5, 7–29

Type material. Holotype female on slide, Brazil, Bahia State, Mucugê municipality, Rio Cumbuco (13°01’03”S; 41°22’11”W), Caatinga Biome, 13.xi.2015, B.C. Bellini coll. Paratypes four females and one male on slides, plus 5 specimens in alcohol, same data as holotype. Type material deposited at Collembola Collection of DBEZ / UFRN.

Description. Total length (head + trunk) of holotype 1.57 mm. Habitus typical of Salina (Fig. 5). Specimens pale white to light yellow with blue to brown pigment covering the Ant. IV–II, lateral head, lateral edges of Th. II– III, medial Abd. III and posterior IV, and entirely the tibiotarsi. Eyepatches, distal margin of Ant. I–III and anterior margin of head dark (Fig. 5). Dorsal head and trunk covered by several ciliate mic and mes.

Head (Figs 5, 7–14). Antennae longer than body, antennal ratio as I: II: III: IV = 1: 1.54–1.56: 1.19–1.92: 1.86– 2.28 (Fig. 5). Ant. IV not subdivided, weakly annulated, with single apical bulb and at least three types of chaetae: blunt sensilla, smooth acuminate chaetae and ciliate chaetae (Fig. 7). Ant. III sense organ with two clubbed sensilla, three surrounding guard sensilla, plus some blunt sensilla, ciliate and smooth chaetae (Fig. 8). Four prelabral ciliate chaetae (Fig. 9). Labral formula 5 (p0–2), 5 (m0–2), 4 (a1–2), all chaetae smooth, a1 thick and apically rounded, posterior row chaetae larger than others (Fig. 9). Clypeal central chaetae formula 2(I1), 4(f1–2), 3(pf0-1), all ciliate, f1 larger than others (Fig. 10). Eyes 8+8, G and H slightly smaller, A-F subequal, with 3 interocular chaetae (Fig. 11). Dorsal chaetotaxy with 6 antennal (An), 2–1 medio-ocellar (M), 3 sutural (S), 3 postsutural (Ps), 3 postoccipital anterior (Pa), 2 postoccipital medial (Pm), and 1 postoccipital posterior (Pp) chaetae; anterior chaetae (A) absent; Pe3 mac present; antero-ocular bothiothrichum absent, post-ocular (Pa6) present (Fig. 11). Labial basolateral and basomedian fields with M, E, L1–2 ciliate, A1–5 smooth; M1 smooth in one specimen, A5 parallel sided, r absent (Fig. 12). Labium with five smooth proximal chaetae; labial palp with five main papillae (A–E), and with 0, 5, 0, 4, 2 guard chaetae, respectively; papilla E with lateral process (l.p.) finger-shaped; H (main hypostomal chaeta) with two accessory hypostomal chaetae (Fig. 12). Maxillary outer lobe with one apical appendage, one subapical chaeta and three sublobal appendages, only the subapical chaeta discretely ciliate, others smooth; subapical chaeta and apical appendage subequal (Fig. 13). Ventral chaetotaxy as in Fig. 14, all chaetae ciliate, long; cephalic groove with 8+8 marginal chaetae, two smaller and smooth; three ventral chaetae present or absent (marked by arrows) (Fig. 14).

Thorax chaetotaxy (Figs 15–16). Pseudopores unclear on all segments. Th. II with 1 S-microchaeta (ms), 1 anterolateral sens (al); 1–0 anterior (a5) excluding the anterior collar, 2–1 medial (m1, m7), and 5 posterior mac (p1, p3–6?) (Fig. 15). Th. III with 1 anterolateral sens (al), and 9–6 posterior mac (p1–3p, p5–6) (Fig. 16).

Abdomen chaetotaxy (Figs 17–21). Pseudopores unclear in all segments. Abd. I with 1 S-microchaeta (ms); 1 anterior (a2), 3–2 medial (m3–5), and 1 posterior (p6) mac (Fig. 17). Abd. II without sens, bothriotricha m2 and a5 present plus 3 mac (m3–3e, m5) (Fig. 18). Abd. III with 1 S-microchaeta (ms), 1 anterosubmedial sens (as), bothriotricha m2, m5 and a5 present plus 6–3 lateral mac (p6–m6, am6, m7?, p7?–i?) (Fig. 19). Abd. IV 1 posterior sens (ps) plus about 11 other sens; primary bothriotricha T2 and T4 plus secondary B6 and bothriotricha like chaetae Fe4–5 present; row ‘A’ with 2 (A1, A6), ‘Ae’ with 1 (Ae1), ‘Be’ with 1 (Be1), ‘B’ with 3 (B3–5), ‘C’ with 1 (C1), ‘E’ with 3 (E1–3), ‘F’ with 4 (F1–3p), and ‘Fe’ with 2 (Fe1–2) mac; 4+4 posterior chaetae (Fig. 20). Abd. V with 1 anterosubmedial sens (as) and 2 accessory sens (acc.p4–p5), 3 anterior (a0, a3, a5), 4 medial (m2– 3, m5–5a), and 4 posterior (p1, p3–4, ap6) mac (Fig. 21).

Legs (Figs 22–23). Trochanteral organ with approximately 17 small smooth chaetae (Fig. 22). Ungues with four inner teeth, one pair basal, one unpaired median, and one minute unpaired distal plus a pair of small outer lateral teeth. Unguiculi excavated, all lamellae smooth. Tenent hairs ciliate, longer than unguis. Pretarsal chaeta (posterior) present (Fig. 23). Tibiotarsus III with a smooth inner distal chaeta, opposite to the tenent hair (Fig. 23).

Collophore (Figs 24–26). Anterior side with 2 large ciliate chaetae plus 8–7 surrounding smooth smaller chaetae (Fig. 24); lateral flap with about 14 smooth chaetae (Fig. 25); posterior side with 2+2 large distal chaetae plus 4–6 surrounding smaller chaetae, all very weakly ciliate (Fig. 26).

Retinaculum and Furcula (Figs 27–29). Retinaculum rami with four teeth; corpus with one weakly ciliate chaeta (Fig. 27). Manubrial plate with two ciliate chaetae plus 1 pseudopore (Fig. 28). Dens smooth with one typical dorso-distal scale-like projection. Mucro square with four teeth, three apical and one medio-internal (Fig. 29).

Etymology. The new species was named after Dr. Feng Zhang, an important Collembola researcher from China.

Distribution and habitat. The new species was found in the Caatinga phytogeographic domain, Northeast Region of Brazil, Good’s biogeographic zone 27 of Neotropical Region (Good 1974). The climate of the area following the Köppen-Geiger system is "Aw" equatorial winter dry (Semi-arid climate), characterized by overall low humidity and little rainfall volume, with averages lower than 60 mm in winter (Kottek et al. 2006). Specimens of S. zhangi sp. nov. were collected in the humid sandy bed of Cumbuco River.

Remarks. The new species fits the celebensis -group proposed by Yoshii (1983) due to the presence of square mucro, reduced macrochaetotaxy and two central and one lateral (near a5 bothriotrichum) mac on Abd. II. Salina zhangi sp. nov. also fits a particular group of Neotropical species with short mucrones with four teeth, as stated by Mari Mutt (1987a), which are: S. panamae Jacquemart, 1982, S. dedoris Mari Mutt, 1987 (in Mari Mutt 1987b), S. hermana Mari Mutt, 1987 (in Mari Mutt 1987b) and S. tristani Denis, 1931 (Mari Mutt 1987a). The overall white to yellowish color pattern and dorsal chaetotaxy of S. zhangi sp. nov. resembles mostly S. hermana and S. tristani, but the new species is differs in dorsal chaetotaxy: Th. II posterior region presents 4–3 internal mac while the other species present 7–5; Th. III of S. zhangi sp. nov. does not have p4 while in the other species is present; Abd. I of the new species has p6? mac which is absent (or omitted) on the other two species; Abd. III of the new species also had one extra lateral mac (m7?) when compared to S. hermana (information lacking to S. tristani). Finally, S. zhangi sp. nov. presents the subapical chaeta of maxillary outer lobe weakly ciliate (smooth in S. hermana) and 17 chaetae on trochanteral organ (12 in S. hermana).