Scutigerella sinensis Jin & Bu, 2023
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https://dx.doi.org/10.3897/zookeys.1157.99686 |
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publication LSID |
lsid:zoobank.org:pub:0FF8F1DF-9CE2-4104-ACF2-FAA9929D261A |
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persistent identifier |
https://treatment.plazi.org/id/21204C04-5009-40AE-B37F-2DC2532C62F3 |
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taxon LSID |
lsid:zoobank.org:act:21204C04-5009-40AE-B37F-2DC2532C62F3 |
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scientific name |
Scutigerella sinensis Jin & Bu |
| status |
sp. nov. |
Scutigerella sinensis Jin & Bu sp. nov.
Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3
Diagnosis.
Scutigerella sinensis sp. nov. is characterized by absence of a3 seta around the antennal base, 6-8 setae on the first tergite, deeply emarginated posterior margin of tergite 2, 28-37 marginal and 41-57 inner setae on tergite 2, less differentiated marginal setae on all tergites, femur of first pair of legs without a conspicuous ventral process, posterior styli without a lateral seta, cavity of fifteenth tergite V-shaped, tarsus of last pair of legs moderately set with setae, cerci 2.7-3.4 times as long as width, cerci densely covered with subequal setae, cerci without expansion in terminal area.
Material examined.
Holotype: male (slide no. SH-DJS-SY2015009) (SNHM), China, Shanghai, Dajinshan Island , extracted from soil samples of bamboo forest, alt. 103 m, 30°41'N, 121°26'E, 30-VI-2015, coll. Y. Bu & Y. L. Jin. GoogleMaps Paratypes: 1 female (slide no. SH-DJS-SY2017001), ibidem, 11-XI-2017; 1 female (slide no. SH-DJS-SY2017002), ibidem, extracted from soil samples of broad-leaf forest, 11-XI-2017, coll. Y. Bu & Y. L. Jin; 1 female (slide no. SH-DJS-SY2018003), ibidem, 24-IV-2018, coll. Y. Bu & J. Y. Li; 1 male (slide no. SH-DJS-SY2018001), ibidem, extracted from soil samples of broad-leaf forest, 24-X-2018, coll. Y. Bu & J. Y. Li; 1 female (slide no. BJ-YMY-SY2021001), China, Beijing, Yuan-Ming Yuan Imperial Garden , extracted from soil samples of a deserted field with herbaceous plants, alt. 60 m, 40°1'N, 116°17'E, 15-IV-2021, coll. R. Q. Wang. GoogleMaps Non-type specimens: 1 juvenile with 8 pairs of legs (slide no. SH-DJS-SY2015002), same data as holotype GoogleMaps ; 1 juvenile with 9 pairs of legs (slide no. SH-DJS-SY2015111), ibidem, 22-IX-2015, coll. Y. Bu & Y. L. Jin; 1 juvenile with 11 pairs of legs (slide no. SH-DJS-SY2018002), ibidem, 24-IV-2018, coll. Y. Bu.
Description.
Adult body 3.4 mm long on average (3.0-4.3 mm, N = 6), holotype 3.2 mm (Fig. 1A View Figure 1 ).
Head length 300-350 μm, width 320-420 μm, broadest part just posterior of midlength, dorsally covered with straight setae of varying lengths (Fig. 1B View Figure 1 ). Antennal base with 3 macrosetae: a1, a2 and a4 (33-50 μm), a3 absent (Fig. 1B View Figure 1 ). Longest seta (43-53 μm) located between Tömösváry organ and spiracle, same length with greatest width of third antennomere. Reticulation of cuticular thickenings present on frons. Central rod complete (150-187 μm), less distinct at most anterior portion, 0.5 times the length of head, with distinct ovoid swollen end (Fig. 1B View Figure 1 ). Dorsal cuticle of head glabrous.
Tömösváry organ subspherical, length 20-22 μm, width 15-20 μm, 0.3-0.4 times as wide as greatest diameter of third antennomere (Fig. 1B View Figure 1 ).
Mouthparts. Mandible similar to Hanseniella . Pars incisivus with four distinct thick teeth, pars molaris with four smaller teeth and one proximal spine, lacinia mobilis with 2 pubescent processes observed from lateral view under light microscope (Fig. 2A View Figure 2 ). First maxilla has two lobes, inner lobe with 4 hook-shaped dorsal teeth and 1 tiny ventral tooth, palp small, with three pointed branches, middle one distinctly longer than lateral ones (Fig. 2B View Figure 2 ). Second maxilla with many small protuberances anteriorly, each carrying one seta, distal setae thicker and spiniform, posterior part with sparse setae, 3+3 spined organs present on anterolateral margin (Fig. 1E, F View Figure 1 ). Cuticle of second maxilla covered with dense pubescence.
Antennae with 19-29 antennomeres (holotype with 29), about 0.4 of body length. First antennomere cylindrical, 1.3-2.5 times wider than long (length 30-45 μm, width 50-75μm), with 5-6 setae in one whorl, longest seta 28-30 μm, about half of antennomere width. Second antennomere 1.3-1.9 times wider than long (width 48-65 μm, length 33-40 μm), with 7-9 setae evenly inserted, longest seta inserted outer-dorsally, about 0.5-0.7 times as long as antennomere width. Third antennomere 1.3-1.9 times wider than long (length 25-40 μm, width 45-65μm), with primary whorl of 7-10 setae, longest seta 0.5-0.7 times as long as antennomere width. Setae on proximal antennomeres longer and on distal antennomeres shorter. Proximal antennomeres each with only primary whorl of setae. Secondary whorl setae appear from antennomeres 6-8 to penultimate antennomere (Figs 1H, I View Figure 1 , 2C, D View Figure 2 ). Four kinds of sensory organs observed on antenna: spiniform sensory organs present on antennomeres 3-5 to distal antennomere increasing in number from 2 to 8, short and thick on proximal antennomeres (Fig. 2C, D View Figure 2 ), long and slender on distal ones (Figs 1H View Figure 1 , 2E View Figure 2 ); one small spined sensory organ consists of several spine and central stub present on dorsal side from fourth antennomere onwards to subdistal antennomere, rarely absent (Fig. 2C, E View Figure 2 ); single tiny conical sensory organ present on outer side of several antennomeres discontinuously distributed along the antenna (Fig. 2C View Figure 2 ); one huge spined sensory organ only present on distal antennomere, distinctly bigger than small ones (Fig. 2E View Figure 2 ). Additionally, one sensory seta decorated with transverse stripes always present on ventral side from second antennomere onwards to penultimate antennomere (Figs 1I View Figure 1 , 2D View Figure 2 ). Distal antennomere longer than wide (length 58-70 μm, width 50-58 μm), with 1 huge spined sensory organ consisting of three or four curved spines stemming from one central stalk on elevated base about 0.3-0.4 times as long as width of antennomere and two neighboring medium ones, 4-7 spiniform organs and 15-22 normal setae on distal half (Fig. 2E View Figure 2 ). Cuticular reticulation present on first and second antennomere, mainly transverse. All antennomeres pubescent. Chaetotaxy and sensory organs of antennae of holotype are given in Table 2 View Table 2 .
Tergites. Tergite 1 rudimentary, with 6-8 subequal setae in one row (Fig. 1C View Figure 1 ). Tergite 2 complete, 1.6 times wider than long (width 295-245 μm, length 155-185 μm), posterior margin deeply emarginated, with 28-37 subequal marginal setae, longest one (25-27 μm) 1.7-1.8 times as long as shortest one (15-17 μm), 0.4-0.6 and 0.2 times as third antennomere respectively; areas surrounded by marginal setae covered by 41-57 inner setae, similar to marginal setae; anterior half with short pubescence on mesh-work covered cuticular thickenings, posterior half with fine dense pubescence (Fig. 1C View Figure 1 ). Tergite 3 complete, broader and longer than tergite 2, 1.5-1.6 times wider than long (width 305-382 μm, length 190-240 μm), posterior margin deeply emarginated, with 36-42 subequal marginal setae, longest one (22-29 μm) 1.7-1.8 times as long as shortest one (12-17 μm), with 58-89 subequal inner setae (Fig. 1D View Figure 1 ). Tergite 4 broader than tergite 3, with 32-39 subequal marginal setae and 44-66 subequal middle setae. Shape of tergites 5-7, 8-10, and 11-13 similar as tergites 2-4. Pattern of alternating tergite lengths of two short-tergites followed by one long-tergite but disrupted at tergite 13. Last tergite with a V-shaped cavity located medially on posterior border. Anterolateral setae on all tergites not differentiated. Cuticle of all tergites densely pubescent. Posterior border of tergites glabrous (Fig. 1C, D View Figure 1 ).
Legs. First pair of legs with 4 segments, trochanter absent; femur 1.8-2.0 times longer than wide (length 38-85 μm, width 28-43 μm), with cuticular reticulation (Fig. 2F View Figure 2 ), with 9-11 setae (Fig. 3A View Figure 3 ), longest seta (33-43 μm) 0.8-1.1 times as long as greatest width of femur; tibia 1.1-1.4 times as long as wide (40-50 μm, 30-38 μm), with total 4 or 5 setae, long pectinate setation (tibial pecten) present distolaterally (Fig. 2F View Figure 2 ), dorsal longest seta (23-28 μm) about 0.6-0.9 times as long as greatest diameter of tibia; tarsus about 3.3-4.6 times as long as wide (65-115 μm, 20-25 μm), slowly tapering towards distal end, with 8-14 setae, longest dorsal setae (18-25 μm) 0.8-1.0 times as long as greatest width of tarsus (Fig. 3A View Figure 3 ). Two slightly curved claws, anterior one somewhat broader and longer than posterior one (Fig. 3A View Figure 3 ). Leg 12 with 5 segments, 1.0-1.6 times as long as length of head; trochanter 1.4-1.7 times as long as wide (113-150 μm, 75-95 μm), dorsal side with cuticular reticulation, with 11-25 setae in total, longest one (20-21 μm) 0.2-0.3 times of greatest width of podomere (Fig. 3B View Figure 3 ); femur 1.1-1.3 times as long as wide (55-95 μm, 58-75 μm), with 6-14 setae and dorsal longest seta (23-28 μm) about 0.3-0.5 times as long as width of podomere (Fig. 3B View Figure 3 ); tibia nearly 1.5-1.9 times longer than wide (80-125 μm, 55-68 μm), with 5 or 6 longitudinal rows of setae, each row with 2-5 setae, longest outer seta (23-30 μm) 0.2-0.3 times as long as greatest width of podomere (Fig. 3B View Figure 3 ); tarsus 2.9-4.0 times as long as wide (105-150 μm, 38-43 μm) with 5 or 6 longitudinal rows of setae, each row with 2-6 setae, outer rows of setae straight and protruding, other setae slightly curved and short, longest seta (23-25 μm) 0.6-0.7 times as long as greatest width of podomere, 4-6 spiniform setae in a row present on ventral surface (Fig. 3B View Figure 3 ). Two claws slightly curved, almost same size. All legs covered with dense pubescence except areas with cuticular reticulation.
Coxal sacs present at bases of legs 3-10, fully developed, each with 5 or 6 setae on surface (Fig. 1J View Figure 1 ). Corresponding area of leg 1, 2, 11, and 12 replaced by 2-3, 2-6, 2-3 and 1 seta respectively.
Styli present at base of legs 3-12, 2.6-4.3 times as long as wide (33-58 μm, 10-20 μm), pubescent, with two distal setae, subapical seta (15-23 μm) 0.3-0.5 times as long as stylus, apical seta (8-10 μm) 0.2-0.3 times as long as stylus, both with pointed apex (Fig. 1J View Figure 1 ).
Sense calicles located on two ventral protuberances of last tergite, posterior to base of leg 12, with smooth margin around pit. Sensory seta inserted in cup center, extremely long (235-275 μm).
Cerci about 0.7-0.9 of head length, distinctly shorter than leg 12, 2.7-3.4 times as long as its greatest width (240-300 μm, 80-110 μm), moderately covered with subequal setae (Fig. 3C View Figure 3 ). Dorsally with 30-59 setae, ventrally with 26-57 setae; longest seta (28-33 μm) 1.3-1.5 times as long as shortest seta (20-28 μm), 0.3-0.4 times as long as greatest width of cercus and 0.1 times as length of cercus. Terminal area glabrous, 0.1 times as long as cercus. Two apical setae pointed, longer seta (43-58 μm) 0.2 times as long as cercus, with granules; shorter seta about a third of the length of longer one. Cuticle with dense pubescence.
Male genitalia with 30 setae in total in holotype, without specialized setae (Fig. 1G View Figure 1 ).
Etymology.
This new species is named after the country of origin, from the Latin adjective sinensis, meaning Chinese.
Distribution.
China (Shanghai, Beijing).
Ecology.
Our current investigation indicates that Scutigerella sinensis sp. nov. is a rare species in natural habitats with very low density. We found about ten individuals among several hundred symphylans from plots of different vegetation. This Scutigerella is often coexisting with other dominant species of Hanseniella and Symphylella in the upper soil layer (0-10 cm) or humus.
Remarks.
The head chaetotaxy was briefly described in the previous studies of Scutigerella , usually with only shapes and numbers mentioned. The macrosetae around the base of the antenna of Scutigerella have been noticed and named by former researchers, and all species examined until now have a complete set of four macrosetae (a1-a4), which was deemed as a good diagnostic character in the taxonomy of Scutigerella ( Hinschberger 1950; Juberthie-Jupeau and Tabacaru 1968; Scheller 1986). Scutigerella sinensis sp. nov. has three macrosetae (a1, a2, and a4) around the antennal base, with a3 seta absent, which can be easily distinguished from all other congeners. Our observation indicates this character is stable in both adults and juveniles and can be a unique feature of the new species. The present new species is most similar to the cosmopolitan species Scutigerella immaculata (Newport, 1845) in the shapes and chaetotaxy of tergites and legs, but differs in the absence of the a3 seta on the head (present in S. immaculata ), number of marginal setae on tergite 2 and 3 (less than 50 in S. sinensis sp. nov. vs. more than 50 in S. immaculata ), and the shape of the stylus (tapering in S. sinensis sp. nov. vs. cylindrical in S. immaculata ).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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