Schendylops ramirezi, Pereira, 2013

Pereira, Luis Alberto, 2013, Discovery Of A Second Geophilomorph Species (Myriapoda: Chilopoda) Having Twenty-Seven Leg-Bearing Segments, The Lowest Number Recorded Up To The Present In The Centipede Order Geophilomorpha, Papéis Avulsos de Zoologia (São Paulo) 53 (13), pp. 163-185 : 163-185

Schendylops ramirezi sp. nov.

( Figs. 1-60 )

Diagnosis: A Neotropical species of Schendylops without pore-field on sternite of the first leg-bearing segment; pore-fields present on anterior region of the body only; all pore-fields undivided; a.a. IV similar in length to the contiguous a.a.; medial edge of forcipular trochanteroprefemur unarmed.

Among the Neotropical species of the genus, these five combined traits are also present in S. anamariae (Pereira, 1981) ; S. interfluvius (Pereira, 1984) ; S. janauarius ( Pereira, Minelli & Barbieri, 1995) ; S. jeekeli Pereira, 2009 ; S. lomanus (Chamberlin, 1957) , S. nealotus (Chamberlin, 1950) ; S. oligopus ( Pereira, Minelli & Barbieri, 1995) ; S. pallidus (Kraus, 1955) ; S. paolettii (Pereira & Minelli, 1993) ; S. perditus (Chamberlin, 1914) and S. virgingordae (Crabill, 1960) .

For a confident identification of the present new species it may be compared in detail with S. oligopus with which it shares the lowest segment numbers in the genus Schendylops , and a very small body size. S. ramirezi sp. nov. can be differentiated from S. oligopus by means of the following selected traits (those for the latter are given in parentheses): male with 27 leg-bearing segments, female with 29 (male with 27 or 29 leg-bearing segments, female with 31); body length up to 7 mm (body length up to 10 mm); clypeus without a clypeal area, Fig. 47 (clypeus with an anterior middle area with areolation smaller than the remaining clypeal surface, Fig. 62 ); coxosternite of first maxillae with 1+1 setae, Fig. 51 (coxosternite of first maxillae devoid of setae, Fig. 65 ); coxosternite of second maxillae bearing a large seta on the middle, Fig. 51 : a (coxosternite of second maxillae without a seta on the middle, Fig. 65 ); single pore-fields accompanied at the anterior sides by a few additional pores, Figs. 28-41 (pore-fields not accompanied at the anterior sides by additional pores, Figs. 67-73 ); pretarsus of ultimate legs as a very small tubercle with a single apical spine, Figs. 44, 45 (pretarsus as a very small tubercle with two apical spines, Fig. 75 ).

Other morphological traits included in Table 1 differentiate S. ramirezi from S. oligopus .

Among the other species mentioned above, those having a range of leg-bearing segments roughly similar to S. ramirezi are S. interfluvius ; S. janauarius ; S. jeekeli ; S. lomanus ; S. paolettii and S. perditus . (For characters differentiating S. ramirezi from these latter species, see Discussion below).

Type material examined: All specimens from Brazil: RJ: Ilha Grande, Praia Grande das Palmas, 19-21 January 1999, M.J. Ramírez leg.: holotype female, 29 l. -b.s., b.l. 7 mm; paratype A (male), 27 l. -b.s., b.l. 5 mm; paratype B (male), 27 l. -b.s., b.l. 6 mm; paratype C (female), 29 l. -b.s., b.l. 6.5 mm; paratype D (female), 29 l. -b.s., b.l. 7 mm; paratype E (male), 27 l. -b.s., b.l. 5 mm.

Remarks: Mandibles of paratype “D” in a permanent microscope slide (remaining body parts in alcohol); holotype and other paratypes in alcohol.

Depository of types: MZUSP .

Other material examined: All specimens from the same locality, date and collector as the type series : 3 males (sub-adult), 27 l. -b.s., b.l. 4.5, 4.5, and 4.5 mm; 2 females (subadult), 29 l. -b.s., b.l. 4.5, 4.5 mm; 13 juvenile females (with 1+1 coxal organs only), 29 l. - b.s., b.l. 3, 3, 3, 3, 3, 3.5, 3.5, 3.5, 3.5, 3.5, 4, 4, and 4 mm; 1 juvenile male (with 1+1 coxal organs only), 27 l. -b.s., b.l. 3 mm ( MZUSP) .

Remarks: The adult condition of all females in the type series is indicated by the two spermathecae full of spermatozoa ( Fig. 27 : a). As for the three male paratypes, no mature spermatozoa have been detected in their tubula seminifera, nevertheless (except for the ultimate leg-bearing segment and postpedal segments) all other morphological traits are similar to those of the female holotype and female paratypes; the penis has a fully developed aspect ( Fig. 60 ), and the coxal organs are completely developed, all these elements being indications of their adult condition.

Male paratypes A and E (5 mm long) have the same morphological attributes as the male paratype B (6 mm long).

Among the juveniles provided with 1+1 coxal organs only, it is possible to distinguish the male from the females on the basis of the different position and shape of the tiny immature gonopods.

Female holotype: twenty nine leg-bearing segments, body length 7 mm, maximum body width 0.37 mm; cephalic plate: length 0.27 mm, maximum width 0.22 mm; maximum width of forcipular coxosternite 0.24 mm. Ground color (of preserved specimen in alcohol) pale yellowish.

Antennae: relatively short, ca. 2.40 times as long as the cephalic plate, distally not attenuate. Length/ width ratio of left a.a. I-XIV as follows: I (0.76: 1); II (1.13: 1); III (1.08: 1); IV (1.10: 1); V (0.99: 1); VI (1.0: 1); VII (0.94: 1); VIII (0.87: 1); IX (0.87: 1); X (0.88: 1); XI (0.81: 1); XII (0.68: 1); XIII (0.62: 1); XIV (1.91: 1). Ratio of width of a.a. II /width of a.a. XIV (1.0: 1). Ventral chaetotaxy: setae on a.a. I to V of different lengths and few in number, those of remaining articles progressively shorter and more numerous towards the tip of the appendage ( Figs. 1, 2 ). Apical a.a. with 7 claviform sensilla on the external border and two on the internal border ( Fig. 3 ); distal end of this a.a. with ca. 4 small hyaline specialized sensilla apparently not split apically ( Fig. 3 ). Ventral and dorsal surface of a.a. II ( Figs. 4 , 8 ), V ( Figs. 5 , 9 ), IX ( Figs. 6 , 10 ) and XIII ( Figs. 7 , 11 ) with very small specialized sensilla. Ventral sensilla of two types (a and b). Type a sensilla very thin and not split apically ( Figs. 5-7 : a), type b sensilla very similar to those of the apex of the terminal a.a., not split apically on a.a. II ( Fig. 4 : b) but are divided in two tiny apical branches on a.a. V, IX and XIII ( Figs. 5-7 : b). Specialized sensilla on dorsal side represented by three different types: a and b similar to a and b of ventral side and type c sensilla, bigger, not divided apically and darker (ochreous in color) ( Fig. 11 : a, b, c). Relative position of specialized sensilla on ventral and dorsal surfaces of the specified a.a. as in Figs. 4-7 and 8-11 respectively. Distribution of type a, b, and c sensilla as in Table 2 .

Cephalic plate: slightly longer than wide (ratio 1.19: 1), anterior border convex, posterior border concave, lateral margins curved. Shape, areolation, and chaetotaxy

as in Fig. 12 . Ratio of maximum width of cephalic plate/maximum width of forcipular tergite, 1.24: 1.

Clypeus: chaetotaxy represented by 1+1 postantennal setae, 4+3 setae distributed on a middle transversal band (of which 1+1 are placed in a lateral position, Fig. 13 : a), and 1+1 prelabral setae ( Fig. 13 ). Surface of clypeus without a clypeal area (similar to female paratype D, Fig. 47 ).

Labrum: with nine dark and short teeth on the central arc, lateral pieces with 2+2 less sclerotized teeth, each with a very sharp medial extension ( Fig. 14 ).

Mandible: dentate lamella apparently not subdivided into blocks, with ca. 8-9 teeth (similar to female paratype D, Figs. 49, 50 ); pectinate lamella with ca. 11-12 teeth.

First maxillae (similar to female paratype D, Figs. 51, 52 ): with lappets on the coxosternite and telopodites, those of coxosternite smaller than the latter. Coxosternite with 1+1 setae; coxal projections round-tipped and provided with 1+1 setae. Article II of telopodites with 1+1 setae on ventral side and 2+2 sensilla on dorsal side.

Second maxillae (similar to female paratype D, Figs. 51, 53-55 ): coxosternite with 1 large seta on the middle ( Fig. 51 : a) and 5+5 smaller lateral setae. Apical claw of telopodites well developed, bipectinate, ventral edge with 4 teeth, dorsal edge with 6 teeth.

Forcipular segment: when closed, the telopodites do not reach the anterior margin of the head ( Fig. 15 ). Forcipular tergite with anterior margin concave, lateral margins curved ( Fig. 12 ); chaetotaxy represented by an irregular transverse median row of eight large setae, and 2+2 lateral much smaller setae distributed near the posterior margin ( Fig. 12 ). All articles of the telopodites without sclerotized teeth ( Fig. 15 ). Tarsungulum with a small pale round-tipped prominence on the basal internal edge. Medial edge of trochanteroprefemur and tibia with diminutive sensilla ( Figs. 19, 20 ). Ventral internal edge of tarsungulum with shape as in Figs. 15, 16 , 18 . Poison glands unusually large (shape and relative size as in Fig. 15 ). Calyx of poison gland very small, shape as in Figs. 16, 17 . Shape and chaetotaxy of coxosternite and telopodites as in Fig. 15 .

Legs (pair 1 to penultimate): first pair shorter and narrower than the second pair, in the proportion of ca. 0.86: 1 ( Figs. 21, 22 ). Chaetotaxy of legs similar throughout the entire body length. Distribution, number, and relative size of setae as in Figs. 21-25 . Claws ventrobasally with three thin and pale accessory spines (one anterior and two posterior), with relative size as in Fig. 26 .

Sternites of leg-bearing segments 1 to penultimate: pore-fields present from sternite 2 to 15 inclusive (wholly absent on the remaining sternites). All pore-fields undivided. Fields accompanied by one-two additional pores at one or both sides of the anterior edge. Shape and relative size of fields changing along the trunk as in Figs. 28-41 . Number of pores as follows: sternite 2 (1+4+2 pores); 3 (1+6+1); 4 (1+10+1); 5 (1+8+1); 6 (1+11+1); 7 (1+8+1); 8 (1+8+1); 9 (2+7+1); 10 (1+6+1); 11 (1+3+1); 12 (1+6+1); 13 (0+5+1); 14 (1+3+0); 15 (1+3+0).

Ultimate leg-bearing segment: intercalary pleurites absent at both sides of the ultimate pretergite ( Fig. 42 ). Ultimate presternite not divided along the sagittal plane; length/width ratio of the tergite, 0.80: 1; length/ width ratio of the sternite 0.70: 1. Shape and chaetotaxy of tergite and sternite as in Figs. 42, 43 . Coxopleura slightly protruding at their distal-internal ventral ends, chaetotaxy represented by a very few large setae distributed as in Figs. 42, 43 . Two single (“homogeneous”) coxal organs in each coxopleuron, both organs unilobed, anterior organ smaller than the posterior in the proportion shown in Figs. 42, 43 , 46 . Relative size of coxal organs in respect to the size of coxopleura and sternite as in Fig. 43 . Coxal organs open on the membrane between coxopleuron and sternite, partially covered by the latter ( Fig. 43 ). Ultimate legs composed of seven articles. Ratio of width of tibia/width of tarsus I, ca. 1.14: 1; ratio of length of tarsus II /length of tarsus I, ca. 1.0: 1. Ratio of length of telopodites of ultimate legs/length of sternite, ca. 3.83: 1. Shape and chaetotaxy of ultimate legs as in Figs. 42, 43 . Ultimate pretarsus represented by a rudimentary terminal tubercle with one diminutive apical spine ( Figs. 44, 45 ).

Postpedal segments: intermediate tergite with posterior margin strongly convex ( Fig. 42 ), intermediate sternite with posterior margin straight, curved on the sides; first genital sternite with posterior margin medially convex, laterally straight to very slightly concave ( Fig. 43 ). Gonopods uniarticulate ( Fig. 43 ).

Male paratype A: twenty-seven leg-bearing segments, body length 5 mm, maximum body width 0.30 mm. All features similar to those in the female except for the shape and chaetotaxy of the ultimate leg-bearing segment and postpedal segments.

Ultimate leg-bearing segment: tergite and sternite trapezoidal, length/width ratio of tergite 0.63: 1; length/ width ratio of sternite 0.60: 1. Shape and chaetotaxy of tergite and sternite as in Figs. 56, 57 . Coxopleura slightly protruding at their distal-internal ventral ends; chaetotaxy represented by a few large setae distributed as in Figs. 56, 57 . Articles of ultimate legs moderately inflated, with shape and chaetotaxy as in Figs. 56, 57 . Ratio of width of tibia/width of tarsus I, ca. 1.14: 1; ratio of length of tarsus II /length of tarsus I, ca. 1.0: 1. Ratio of length of telopodites of ultimate legs/length of sternite ca. 4.20: 1.

Postpedal segments: intermediate tergite with posterior margin convex ( Fig. 56 ), intermediate sternite with posterior margin medially straight, laterally slightly curved, first genital sternite with posterior border slightly convex ( Fig. 57 ). Gonopods biarticulate, basal article with a single seta, apical article without setae ( Figs. 57-59 ), penis without apical setae, shape as in Fig. 60 .

Variation: Antennal article XIV bearing ca. 2-3 claviform sensilla on the internal edge and ca. 7-8 sensilla on the external edge.

In all adult specimens examined, the pore-field series starts on sternite 2 but the posterior limit varies between sternites 13 and 15.

All females have 29 leg-bearing segments, all males 27.

Post-embryonic variation of pilosity of coxosternite of first maxillae: All juveniles having 1+1 coxal organs only, lacking setae on the coxosternite of the first maxillae; conversely, all specimens with 2+2 coxal organs

have setae on this coxosternite: 0+1 or 1+ 1 in the sub-adults, and 1+ 1 in all adults.

Post-embryonic variation of pilosity of coxosternite of second maxillae: All juvenile specimens having 1+1 coxal organs only, lacking a central seta on the coxosternite of the second maxillae; conversely, all specimens having 2+2 coxal organs (sub-adults and adults) bear that seta ( Fig. 51 : a).

Remarks: Pereira et al., (1995) is the original source for the nomenclature of the three types of specialized sensilla (a, b, and c) present on a.a. II, V, IX and XIII.

Male paratypes A and E (5 mm long), having the same form and pilosity of gonopods, shape of penis, and shape and pilosity of ultimate leg-bearing segment and postpedal segments, as the male paratype B (which is 6 mm long).

Etymology: The species is respectfully dedicated to the collector of all type and non-type specimens herein described, Dr. Martín Javier Ramírez, researcher of CONICET, working at the Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina.

Ecology: The locality in which all specimens herein described have been collected is part of the Atlantic Rainforest biome.

Type locality: Brazil: RJ: Ilha Grande, Praia Grande das Palmas.

Known range: Only known from the type locality.

Figures

FIGURES 1‑7: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (1) Left a.a. I-VI, ventral; (2) Left a.a. VII-XIV, ventral; (3) Left a.a. XIV, ventral; (4) Left a.a. II, ventral (b: b type sensilla); (5) Left a.a. V, ventral (a, b: a, b type sensilla); (6) Left a.a. IX, ventral (a, b: a, b type sensilla); (7) Left a.a. XIII, ventral (a, b: a, b type sensilla). Scale bars: 0.03 mm (3); 0.05 mm (4-7); 0.2 mm (1, 2).

FIGURES 8‑12: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (8) Left a.a. II, dorsal (a: a type sensilla); (9) Left a.a. V, dorsal (a, b: a, b type sensilla); (10) Left a.a. IX, dorsal (a, b, c: a, b, c type sensilla); (11) Left a.a. XIII, dorsal (a, b, c: a, b, c type sensilla); (12) Dorsal view of anterior region of the body, showing cephalic shield, bases of antennae, forcipular segment, leg-bearing segment 1, and small anterior portion of leg-bearing segment 2. Scale bars: 0.05 mm (8-11); 0.2 mm (12).

FIGURES 13‑17: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (13) Clypeus and bases of antennae (a: lateral setae of clypeus); (14) Labrum; (15) Ventral view of anterior region of the body, showing clypeus, labrum, bases of antennae, forcipular segment, leg-bearing segment 1, and small anterior portion of leg-bearing segment 2 (first and second maxillae not drawn); (16) Duct and calyx of poison gland in right forcipular telopodite, ventral; (17) Detail of calyx of right poison gland, ventral. Scale bars: 0.02 mm (17); 0.05 mm (14); 0.1 mm (16); 0.2 mm (13, 15).

FIGURES 18‑20: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (18) Detail of ventral internal edge of right forcipular tarsungulum (a: sensilla); (19) Left forcipular telopodite, showing sensilla on medial edge of trochanteroprefemur and tibia (a: sensilla); (20) Detail of sensilla on trochanteroprefemur and tibia of left forcipular telopodite, ventral (a: sensilla). Scale bars: 0.02 mm (18); 0.05 mm (19, 20).

FIGURES 21‑26: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (21) Left leg (pair 1), ventral; (22) Left leg (pair 2), ventral; (23) Left leg (pair 4), ventral; (24) Left leg (pair 14), ventral; (25) Left leg (pair 28), ventral; (26) Claw of left leg (pair 13), antero-ventral view. Scale bars: 0.02 mm (26); 0.1 mm (21-25).

FIGURES 27‑35: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (27) Leg-bearing segments 25-26, ventral (a: spermathecae); (28) Sternite 2; (29) Sternite 3; (30) Sternite 4; (31) Sternite 5; (32) Sternite 6; (33) Sternite 7; (34) Sternite 8; (35) Sternite 9. Scale bars: 0.1 mm (28-35); 0.2 mm (27).

FIGURES 36‑41: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (36) Sternite 10; (37) Sternite 11; (38) Sternite 12; (39) Sternite 13; (40) Sternite 14; (41) Sternite 15. Scale bar: 0.1 mm.

FIGURES 42‑45: Schendylops ramirezi sp. nov., (female holotype; Brazil: RJ: Ilha Grande): (42) Penultimate and ultimate leg-bearing segments, and postpedal segments, ventral; (43) Penultimate and ultimate leg-bearing segments, and postpedal segments, dorsal; (44) Detail of distal end of last podomere of left ultimate leg, ventral; (45) Detail of distal end of last podomere of right ultimate leg, ventral. Scale bars 0.02 mm (44, 45); 0.2 mm (42, 43).

FIGURES 46‑55: (46): Schendylops ramirezi sp.nov., (female holotype; Brazil:RJ: Ilha Grande):Right coxal organs,ventral.(47-55): Schendylops ramirezi sp. nov., (female paratype D; Brazil: RJ: Ilha Grande): (47) Clypeus and bases of antennae; (48) Labrum; (49) Right mandible, dorsal; (50) Detail of dentate lamella of right mandible, dorsal; (51) First and second maxillae, ventral (a: large middle seta); (52) First maxillae, dorsal; (53) Claw of right telopodite of second maxillae, ventral; (54) Claw of right telopodite of second maxillae, dorsal; (55) Claw of left telopodite of second maxillae, dorsal. Scale bars: 0.02 mm (49, 50); 0.03 mm (53-55); 0.05 mm (48, 52); 0.1 mm (46, 51); 0.2 mm (47).

FIGURES 56‑60: Schendylops ramirezi sp. nov., (male paratype A; Brazil: RJ: Ilha Grande): (56) Ultimate leg-bearing segment and postpedal segments, dorsal; (57) Ultimate leg-bearing segment and postpedal segments, ventral; (58) Detail of postpedal segments, ventral; (59) Gonopods, ventral; (60) Penis, dorsal. Scale bars: 0.03 mm (59); 0.05 mm (58, 60); 0.2 mm (56, 57).

FIGURES 61‑66: Schendylops oligopus (Pereira, Minelli & Barbieri, 1995) (female holotype; Brazil: Amazonas: Reserva Florestal A. Ducke): (61) Clypeus and bases of antennae; (62) Clypeal area; (63) Labrum; (64) Dentate lamella of mandible; (65) First and second maxillae, ventral; (66) Duct and calyx of poison gland in left forcipular telopodite, ventral. (After Pereira et al., 1995). Scale bars: 0.02 mm (64); 0.05 mm (62, 63, 66); 0.1 mm (65); 0.2 mm (61).

FIGURES 67‑76: Schendylops oligopus (Pereira, Minelli & Barbieri, 1995) (female holotype; Brazil: Amazonas:Reserva Florestal A. Ducke): (67) Sternite 2; (68) Sternite 3; (69) Sternite 5; (70) Sternite 7; (71) Sternite 9; (72) Sternite 12; (73) Sternite 13; (74) Ultimate legbearing segment and postpedal segments, ventral; (75) Detail of distal end of last podomere of left ultimate leg, ventral; (76) Right coxal organs, ventral. (After Pereira et al., 1995). Scale bars: 0.02 mm (75); 0.05 mm (76); 0.1 mm (67-74).