Research Article |
Corresponding author: Guo-Liang Xu ( xugl@gzhu.edu.cn ) Academic editor: Louis Deharveng
© 2016 Guo-Liang Xu, Wei-Yu Chen.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Xu G-L, Chen W-Y (2016) Two new species of Sinella from Guangdong Province, China (Collembola: Entomobryidae). ZooKeys 611: 1-10. https://doi.org/10.3897/zookeys.611.9025
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Two new blind species of Sinella are described from Guangdong Province, China. Sinella colubra sp. n. possesses minute smooth postlabial chaetae, long mucronal spine, and 4+4(5) lateral mac on Abd. IV, and can be distinguished from two closely related species by the postlabial chaetae and the dorsal macrochaetotaxy. Sinella zhangi sp. n. is also described and can be diagnosed by having minute labial chaeta r and postlabial chaetae X and X4, 5+5 mac on Abd. I, 4+4 central mac on Abd. II, and 4+4 central and 5+5 lateral mac on Abd. IV.
Blind species, chaetotaxy, springtail, Sinella colubra sp. n., Sinella zhangi sp. n., South China
The genus Sinella Brook, 1882 is distributed worldwide and is very abundant in China.
Specimens were cleared in Nesbitt’s fluid (
Th. thoracic segment
Abd. abdominal segment
Ant. antennal segment
mac macrochaeta/ae
mic microchaeta/ae
mes mesochaeta/ae
ms S-microchaeta/ae
sens ordinary tergal S-chaeta/ae
Holotype: ♂ on slide, China, Guangdong Province, Huizhou City, Longmen County, Nankunshan Natural Reserve, 23°38'4.01”N, 113°51'15.25”E, altitude 497 m, 24 August 2010, Z-X Pan and Y-T Ma leg. (# S4143). Paratypes: ♂ and 3 ♀♀ on slides and 3 in alcohol, same data as holotype.
♀ on slide, China, Guangdong Province, Nanling National Natural Reserve, 24°55'42.6"N, 113°0'58.3"E, altitude 1026 m, 22 July 2010, F Zhang and Z-H Li leg. (# C9640).
No eyes. Long smooth straight chaetae present on antennae. Clypeal chaetae eight and median three much smaller. Labial chaetae as mrel1l2. Postlabial chaetae X and X2‒4 minute. “Smooth” inner differentiated tibiotarsal chaetae present. Manubrium without smooth chaetae. Mucronal spine long, with tip nearly reaching apical tooth. Abd. I with 6+6 mac. Abd. II with 3+3 central mac. Abd. IV with 7+7 central and 4+4 lateral mac.
Comparison among S. colubra sp. n., S. insolens and S. sineocula. Rare character states are noted and placed in parentheses.
Characters | S. colubra sp. n. | S. insolens | S. sineocula |
Mac in Gr. II on dorsal head | 3(4) | usually 4‒5(6‒8) | usually 5‒6(4) |
Labial chaeta M1s | absent | present | absent |
Postlabial chaetae X and X2‒4 | smooth, minute | cliate, large | ciliate, large |
Mac m5i on Th. III | absent | present | absent |
Mac on Abd. I | 6+6 | 7(6)+7(6) | 7(6)+7(6) |
Central mac on Abd. II | 3+3 | 4+4 | 3+3 |
Lateral mac on Abd. IV | 4(5)+4(5) | 6+6 | 6+6 |
Body length up to 1.50 mm. Body pale in alcohol.
Antenna 1.63‒1.93 times as long as cephalic diagonal. Antennal segments ratio as I : II : III : IV = 1 : 1.77‒2.00 : 1.64‒1.74 : 2.57‒2.91. Smooth spiny mic at base of antennae: three dorsal, three ventral on Ant. I; one internal, one external and two ventral on Ant. II. Ant. II distally with one (rarely two) rod-like sens. Ant. III organ with two slightly expanded internal sens. Ant. IV with a knobbed subapical organ. Ant. II. with 2‒4 ventral long smooth straight chaetae.
Eyes absent in all specimens. Prelabral and labral chaetae 4/ 5, 5, 4, all smooth; labral intrusion U-shaped (Fig.
Sinella colubra sp. n. 1 labrum 2 clypeal chaetae 3 dorsal cephalic chaetotaxy 4 lateral process and labial papilla E 5 chaetae on the ventral side of head 6 trochanteral organ 7 hind claw 8 anterior face of ventral tube 9 ventral face and lateral flap of ventral tube 10 distal part of anterior face of manubrium 11 manubrial plaque 12 mucro.
Trochanteral organ with 17‒19 smooth spiny chaetae; 11–12 in arms and 5‒7 internal (Fig.
Th. II with three medio-medial mac (m1, m2, m2i), three medio-lateral mac (m4, m4i, m4p), 14‒18 posterior mac, one ms and two sens; ms interior to sens al. Th. III with 29‒32 mac and two lateral sens; a6i, p5, p6, m6, m6i, m6p, m6e and m6ai2 present as mac; mac m5i absent (Fig.
Named after the snake Bungarus multicinctus Blyth found in the sampling site.
In soil of bamboo forest, near termitarium.
Sinella colubra sp. n. is most similar to Sinella insolens Chen & Christiansen, 1993 and Sinella sineocula Chen & Christiansen, 1993 in morphology of unguis and unguiculus, long mucronal spine, absence of smooth chaetae on manubrium, medial and posterior mac on Th. II, 1+1 central and 3+3 lateral mac on Abd. III, and 7+7 central mac on Abd. IV. It differs from them in 3+3(4) cephalic mac on Gr. II, absence of labial chaeta M1s, minute postlabial chaetae X and X2‒4, absence of mac m5i on Th. III, 6+6 (a2 as mes) mac on Abd. I, absence of mac m3ei on Abd. II, and 4+4(5) lateral mac on Abd. IV.
Holotype: ♂ on slide, China, Guangdong Province, He Mountain, in soil of secondary eucalypt forest, 22 October 2012, Guoliang Xu leg. (# Xu-2012). Paratypes: 1 ♀ on slide and 1 juvenile in alcohol, same data as holotype.
No eyes. Long smooth straight chaetae absent on antennae. Labial chaeta r and postlabial chaetae X and X4 minute. “Smooth” inner differentiated tibiotarsal chaetae present. Tenent hairs clavate. Manubrium without smooth chaetae. Mucronal spine short, with tip reaching subapical tooth. Chaeta p5 as mac on Th. II. Abd. I with 5+5 mac. Abd. II with 4+4 central mac. Abd. IV with 4+4 central and 5+5 lateral mac.
Body length up to 1.32 mm. Body pale in alcohol.
Antenna 2.04 times as long as cephalic diagonal. Antennal segments ratio as I : II : III : IV = 1 : 1.71 : 1.86: 2.71. Smooth spiny mic at base of antennae three dorsal, three ventral on Ant. I: one internal, one external and one ventral on Ant. II. Ant. II distally with one rod-like S-chaeta. Two internal sens of Ant. III organ rod-like. Long smooth straight chaetae absent on antennae.
Eyes absent in all specimens. Prelabral and labral chaetae 4/ 5, 5, 4, all smooth; three chaetae of first row longer than lateral chaetae. Clypeal chaetae not clearly seen. Dorsal cephalic chaetotaxy with four antennal, three median (M) and eight sutural (S) mac; Gr. II with four mac (Fig.
Trochanteral organ with nine smooth spiny chaetae; five in arms and four internal. Some inner differentiated tibiotarsal chaetae “smooth” with ciliations closely appressed to axis. Tibiotarsi distally with ten chaetae in a whorl. Unguis with three inner teeth; two paired teeth unequal, outer one larger. Unguiculus with a large outer tooth. Tenent hairs clavate (Fig.
Th. II with three medio-medial mac (m1, m2, m2i), three medio-lateral mac (m4, m4i, m4p), 19 posterior mac, one ms and two sens; ms interior to sens al. Th. III with 30 mac and two lateral sens (Fig.
Named after the Chinese collembologist Dr. Feng ZHANG, who has made great contributions to the taxonomy of Sinella.
In decomposing leaves along the roads.
Sinella zhangi sp. n. is most similar to Sinella quadriseta Zhang, Bedos & Deharveng, 2014 in absence of eyes, tip of lateral process of labial palp beyond apex of labial papilla, morphology of unguis and unguiculus, and mucronal spine, but differs from it in smooth, minute labial and postlabial chaetae r, X and X4, clavate tenent hairs, “smooth” inner differentiated tibiotarsal chaetae, 4+4 mac in Gr. II on dorsal head, absence of mac m2, m2i, m4i and m4p on Th. II, 5+5 mac on Abd. I (m4p present), and 4+4 central mac on Abd. II (m3ep present). It is also similar to Chinese species Sinella affluens Chen & Christiansen, 1993 in 4+4 mac on dorsal head, “smooth” inner differentiated tibiotarsal chaetae, clavate tenent hairs, number of teeth on unguis and unguiculus, minute postlabial chaetae X and X4, 2+2 pseudopores and 3+3 ciliate chaetae on manubrial plaque, medial mac on Th. II, 1+1 central mac on Abd. III, and 4+4 central mac on Abd. IV, but differs from the latter in absence of eyes, short mucronal spine, minute labial chaeta r, p5 present as mac on Th. II, m5i present as mac on Th. III, 5+5 mac on Abd. I (a3) as mes, 4+4 central mac on Abd. II (a2 as mac), 5+5 lateral mac on Abd. IV (F1 as mac).
Thanks are given to Dr. Feng Zhang (NJAU), who provided the material and facilities when we visited his lab in August, 2015.Thanks should be given to Mr. Morgan A. McClure, who helped to check the English text. The present study was supported by the National Natural Sciences Foundation of China (41571247) and High Level University Construction Project of Guangdong Province (Regional Water Environment Safety and Water Ecological Protection).