Paracerura serrana, Mendonça, Maria Cleide De, Abrantes, Eduardo Assis & Fernandes, Liliane Henriques, 2009

Mendonça, Maria Cleide De, Abrantes, Eduardo Assis & Fernandes, Liliane Henriques, 2009, Two new Brazilian species of Paracerura Deharveng & Oliveira (Collembola: Isotomidae), Zootaxa 2310, pp. 24-34 : 30-32

Paracerura serrana sp. nov.

Figs 2 , 21–45 , Tab. 1

Type material. Holotype male: Brazil, State of Minas Gerais, “Parque Nacional de Itatiaia”, Aiuruoca Valley (1600 meters of altitude) on litter near a trunk in decomposition, 09.xi.1990, collection number CM/ MNRJ 345. Mendonça, M.C. coll. Paratypes: CM/ MNRJ 343, 2 specimens on slides, 1 specimen in ethanol; CM/ MNRJ 345, 6 specimens on slides, 5 specimens in ethanol; CM/ MNRJ 346, 1 specimen on slide; CM/ MNRJ 350, 1 specimen on slide, 2 specimens in ethanol, 09.xi.1990, Mendonça, M.C. coll.

Description. Body length of holotype: 1.58 mm. Body tegument with fine primary granulation, without craters. Color generally pale with strong brownish pigmentation. Head slightly pigmented in the anterior part, with an intense irregular small spot in the posterior part. Antennae with pigment in the proximal parts of the segments. Mesonotum and metanotum strongly pigmented in the anterior and lateral regions and pale in the posterior regions. Abdominal tergites with transversal narrow bands of pigment in the distal parts. Legs and furca pale ( Fig. 2 ).

Body chaetotaxy. Plurichaetotic, smooth common setae with different sizes ( Fig. 22 ). Head chaetotaxy abundant with longer setae in the frontal, lateral and posterior areas ( Fig. 23 ). Macrochaetotaxy clearly differentiated and slightly ciliated in the abdominal segment VI, some of them reaching 180 µm. Axial setae without defined pattern. Macrosensillary and microsensillary set by half tergite respectively with 3,3/ 2,2,3,10–12,8–9 and 1,1/1,1,0,0,0; macrosensilla long and thin (20 µm); macrosensilla on abdominal segment V (accp and as) with spiraled trace ( Fig. 24 ).

Head. Eyes 8+ 8 in pigmented eye patch. Postantennal organ (38 µm) elongated and elliptical with chitinous borders, 3–4 surrounding setae ( Fig. 25 ). Antennae plurichaetotic, longer than the head diagonal, covered by common and acuminated setae with different sizes. Ratio antennae: head diagonal = 1.5: 1. Antennal segment IV with grape-seed shape subapical organite and innumerous dorsolateral sensilla along the segment ( Figs 26–27 ). Antennal segment III with about 80 setae, 2 inner broad sensilla covered by an integumentary fold, 2 guard sensilla, 2 lateral outer lateral microsensilla, 3 dorsolateral inner sensilla and one dorsal basal microseta. ( Figs 28–29 ). Antenal segment II with about 70 setae, 3 dorsal medial sensilla, 5 basal microsetae (2+2 dorsolateral and one ventral) ( Fig. 27 ). Antennal segment I with about 28 setae, 7 basal microsetae (4 dorsal and 3 ventral), 2-3 ventral and subequal sensilla ( Figs 30-31 ). Ratio of antennal segments I: II: III: IV= 1: 2.1: 2: 2.6. Labrum with 4 roundish apical folds and ventral ciliation, 4 prelabral setae and 5,5,4 labral setae inserted on papillae. Mandible with well developed molar plate. Maxillary capitulum with 3 teeth and 6 ciliated and subequal lamellae, with marginal ciliations ( Fig. 32 ). Maxillary outer lobe bifurcated with 4 strong sublobal hairs and one basal seta ( Fig. 33 ). Labial palp with 5 papillae and one lateral process surpassing the E papilla. Head with 3+3 setae along linea ventralis ( Fig. 34 ).

Appendages. Femora I, II and III with one setae in the inner part longer than the others, measuring respectively 115µm, 105µm and 98µm ( Fig. 35 ). Tibiotarsi I, II and III respectively with 26–32, 25–30 and 47–54 setae, tenent hair in the distal whorl pointed (45 µm).

Unguis long and thin (78 µm) with one inner, 1+1 lateral and one dorsal tooth. Unguiculus (36 µm) long and thin with conspicuous apical filament ( Figs 36–37 . Ventral tube with 4–7+4–7 apical, 7–8+7–8 anterior and 7 posterior setae ( Fig. 38 ). Retinaculum with 4+4 teeth and 7–10 setae on corpus ( Fig. 39 ). Furcal subcoxa anterior with 31–36 setae ( Fig. 40 ) and posterior with about 13 setae ( Fig. 41 ). Anterior manubrium with about 21 central proximal, 24+24 distal and 10–12 lateral setae ( Fig. 42 ). Dens crenulated with about 240 anterior smooth setae, internal margin with a row of 22–31 spine like setae, whose size increase toward the mucro and about 31 posterior setae ( Figs 43–44 ). Mucro quadridentate (one proximal external, 2 robust medial and one reduced apical), without seta ( Fig. 45 ). Ratio manubrium: dens: mucro = 6.4: 17.4: 1.

Derivatio nominis. The name serrana refer s to “Serra do Itatiaia”, region of the Mantiqueira Mountains, where the species was found.

Discussion. Comparing the morphology of P. serrana sp. nov. with P. a i re s i sp. nov. and P. virgata , some general similarities were observed: the same sensillary formula from thorax II to abdominal III (4,4/3,3,3), number of eyes, postantennal organ, number of setae along linea ventralis, retinaculum teeth and mucro. Unfortunately, it was not possible to compare the sensillary formula of P. serrana sp. nov. with P. itatiaiensis ( Arlé, 1959) as the sensillary set was omitted by the author. The paratypes and holotype of this species, according to Arlé, were deposited in the Museu Nacional/Universidade Federal do Rio de Janeiro, but they can not be found and are probably lost. In the samples from Parque Nacional de Itatiaia, at 1600 meters of altitude, we found several specimens of P. serrana sp.nov. that we judged in the occasion to be P. itatiaiensis ( Arlé, 1959) because of the similarity in the pigment pattern distribution (more intense in the anterior regions of the mesonotum and metanotum) described by the author. However, the coloration in P. serrana sp. nov. is brownish while the other species of genus, including P. itatiaiensis , present bluish to violaceous pigmentation.

Within the species of the genus Paracerura the new species is more similar to P. itatiaiensis by the unguiculus with filament and the internal row of spine like setae on dens. However, in P. serrana sp. nov. the filament is longer and the number (22–31) of spine like setae is higher.

Another difference between all species is the strong plurichaetosis and the presence of some ciliated macrosetae on the last abdominal segments in P. serrana sp. nov., while the other species show smooth setae. Furthermore, the peculiar aspect of the subapical organite on the segment IV, the dorsal sensillary formula on segment abdominal IV–V, the long femoral seta on legs and the number and patterns of manubrium/dens setae, undoubtedly distinguish the new species from the others species of the genus.

Figures

FIGURES 1 – 2. Habitus and color pattern: 1, Paracerura airesi sp. nov.; 2, P. serrana sp. nov.

FIGURES 14 – 21. Paracerura airesi sp. nov.: 14, tip of leg III, dorsal view; 15, leg III; 16, retinaculum; 17, anterior furcal subcoxa; 18, posterior furcal subcoxa;, 19, furca with magnification of mucro, anterior view; 20, male genital plate; 21, female genital plate.

FIGURES 22 – 24. Paracerura serrana sp. nov.: 22, body chaetotaxy; 23, head chaetotaxy; 24, tergal sensilla of abdominal segments IV – V with magnification of sensillum.

FIGURES 25 – 37. Paracerura serrana sp. nov.: 25, PAO and eyes; 26, antennal segment IV; 27, distribution of sensilla in antennal segment IV; 28, antennal segments II – III; 29, antennal III organ; 30, antennal segment I, dorsal view; 31, antennal segment I, ventral view; 32, maxillary head; 33, maxillary outer lobe; 34, labial palp and ventral line; 35, femur of leg I; 36, tibitarsus of leg III; 37, tip of leg III.

FIGURES 38 – 45. Paracerura serrana sp. nov.: 38, ventral tube; 39, retinaculum; 40, anterior furcal subcoxa; 41, posterior furcal subcoxa; 42, manubrium, anterior view; 43, dens, posterior view; 44, dens, anterior view; 45, mucro.