The first description of the adult female of Araneus yoshitomii (Araneae: Araneidae)

Abstract

Adult female of Araneus yoshitomii Yoshida 2014 has been described for the first time. The conspecific pair of male and female specimens was confirmed by DNA barcoding using mt-COI partial sequencing data.

Full text

Araneus yoshitomii Yoshida 2014 was described based on
the male holotype, and two male paratypes. As for the female,
only one sub-adult specimen was examined as “other speci-
mens” in the original description (Yoshida 2014). To date, an
adult female of this species has not been described. Therefore,
in this study, I describe an adult female of this species.
The specimens were preserved in a 75% ethanol solution
at ambient temperature (18–27℃). The morphological char-
acteristics were examined under a stereoscopic microscope
(M3Z, Wild Heerbrugg AG, Heerbrugg, Switzerland), and
images were captured using an EOS Kiss X7 with an EF-S
60-mm f2.8 macro photo lens (Canon Inc., Tokyo, Japan)
or attached to the microscope. All the measurements are
presented in millimeters (mm). The voucher specimens in
this study were deposited in the collection of the National
Museum of Nature and Science, Tsukuba (NSMT), Japan.
All the specimens used in this study were collected under
permission.
I conducted DNA barcoding using mt-COI sequencing
data to conrm the conspecic pair of female and male spec-
imens (Fig. 1). Genomic DNA was extracted from the right
fourth leg using DNeasy Blood & Tissue kit (Qiagen, Inc.,
Germantown, MD). Mt-COI was amplied using the primer
set LCO1498: 5′-GGT CAA CAA ATC ATA AAG ATA TTG
G-3′ and HCO2198: 5′-TAA ACT TCA GGG TGA CCA
AAA AAT CA-3′ (Folmer et al. 1994). The reactants were
initially denatured for 2 min at 94 °C, followed by 40 cy-
cles of 15 s at 94 °C, 20 s at 47 °C, and 30 s at 72 °C. PCR
products were purified using ExoSAP-IT (GE Healthcare
Life Sciences, Little Chalfont, United Kingdom). Purified
PCR products were sequenced commercially by the Genetic
Analysis Division, FASMAC Co. Ltd. (Kanagawa, Japan)
using an ABI 3730xl DNA Analyzer (Life Technologies
Japan Ltd., Tokyo, Japan). Chromatograms were assessed
using MEGA ver. 7 software (Kumar et al. 2016), and se-
quence alignments were performed using MUSCLE (Edgar
2004) in the MEGA. Alignments were translated into amino
acids and screened for the presence of stop codons. Phylo-
genetic tree was constructed with the UPGMA method using
MEGA. The nucleotide sequence data obtained in this study
are available in the DDBJ/EMBL/GenBank databases.
Araneus yoshitomii Yoshida 2014
[Japanese name: Ogasawara-onigumo]
(Fig. 1–2)
Araneus yoshitomii Yoshida 2014, p. 37, gs. 1–6, holotype male, and
male paratypes from Hahajima Is., Ogasawara Isls., Tokyo, Japan,
preserved in NSMT, not examined.
Specimens examined. All specimens were collected in
Ogasawara Isls., Tokyo, Japan. 1♂, 4-VII-2014, Chichijima
Is., Takeshi Osawa & Yuki Murakami leg. 1♂2♀, 17-IX-
2022, Hase-dam, Chichijima Is., Yuya Suzuki leg. 1♀, 18-
III-1988, Tatsumizaki, Chichijima Is., Norihisa Tanaka leg.
Description of female. Based on a female from Chichi-
jima Is. Body 7.5 long. Carapace 2.68 long; 2.18 wide, pale
yellow with blackish markings. Median ocular area wider
than long [length / width 0.89]; wider in front than behind
[anterior width / by posterior width 1.19]. Labium wider
than long [length / width 0.75]. Sternum longer than wide
[length / width 1.32]. Length of legs [tarsus, metatarsus,
tibia + patella, femur = total]: I, 1.16, 2.72, 4.31, 3.19 =
11.38; II, 1.06, 2.63, 3.81, 2.88 = 2.08; III, 0.69, 1.28, 1.69,
1.94 = 1.12; IV, 0.78, 2.16, 2.97, 2.56 = 1.69. Length of leg
I / length of carapace 4.25. Abdomen 4.38 long; 1.63 wide,
blackish brown with a longitudinal white band at the center
and a pair of white marking at both sides. Epigyne as in Fig.
2 (A–C), scape wrinkled, slim, and long; both sides covered
by a semitransparent dome.
Variations. Female body length varies from 5.69 to 8.40.
Markings of dorsal side of abdomen are somewhat varied as
Acta Arachnologica, 72 (1): 13–16, June 20, 2023
The rst description of the adult female of Araneus yoshitomii (Araneae: Araneidae)
Akio Tanikawa
Laboratory of Biodiversity Science, School of Agriculture and Life Sciences,
The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
E-mail: dp7a-tnkw@j.asahi-net.or.jp
Abstract ― Adult female of Araneus yoshitomii Yoshida 2014 has been described for the rst time. The con-
specic pair of male and female specimens was conrmed by DNA barcoding using mt-COI partial sequenc-
ing data.
Key words ― barcoding, COI, taxonomy

A. Tani kawa
８
Fig.1 133
134
135
136
137
Fig. 1. An unrooted tree obtained by the UPGMA method. Scores at each node are bootstrap values (1000 replicates). The scale bar shows substi-
tutions per site.
Fig. 2. Araneus yoshitomii Yoshida 2014. A, cleared epigyne, ventral view; B, same, posterior view; C, same, dorsal view; D–F, female habitus.
Scales, A–C, 0.1 mm; D–F, 2 mm.
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Acta Arachnologica, 72 (1), June 2023 ⒸArachnological Society of Japan

Female of Araneus yoshitomii
in Fig. 2 (D–G).
Remarks. The female of A. yoshitomii is easily separated
from the other species of Araneus by the shape of epigyne
having a semitransparent dome. It is possible that this spe-
cies should be transferred to another genus or established
new genus, but it is required to clarify its phylogenetic posi-
tion among the family Araneidae rst.
Distribution. Ogasawara Isls, Japan.
Acknowledgments
I wish to express my heartfelt thanks to the following people for their
kind help with my study. Yuki G. Baba, Institute for Agro-Environ-
mental Sciences; Yuya Suzuki, Kyushu University; Norihisa Tanaka,
Kanagawa Prefectural Museum of Natural Hisitory; and Tadashi Mi-
yashita, the University of Tokyo. This work was supported in part by
JSPS KAKENHI Grant-in-Aid for Scientic Research (A) 24710038.
References
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Received November 1, 2022 / Accepted January 13, 2023
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A. Tani kawa
Appendix
Specimens used for molecular work in this study.
Species Sex Locality Accession No.
A. matsumotoi ♂ Izuhara, Tsushima-shi, Nagasaki Pref. LC630881
A. reizan ♂Mt. Tatsugane, Minami-sanriku-cho, Miyagi Pref. LC516592
A. reizan ♀ Mt. Tsukuba, Tsukuba-shi, Ibaraki Pref. LC516593
A. ventricosus ♀ Iwatomi, Sakura-shi, Chiba Pref. LC516594
A. ventricosus ♀Lake Shikotsuko, Chitose-shi, Hokkaido LC516595
A. macacus ♀ Tsukuba-shi, Ibaraki Pref. LC516596
A. macacus ♀Lake Shikotsuko, Chitose-shi, Hokkaido LC516597
A. uyemurai ♀Lake Shikotsuko, Chitose-shi, Hokkaido LC516598
A. uyemurai ♀Yuza-machi, Akumi-gun, Yamagata Pref. LC516599
A. seminiger ♀Kimitsu-shi, Chiba Pref. LC516600
A. ogatai ♀Noda-shi, Chiba Pref. LC735300
A. ishisawai Juvenile Ngano-shi, Nagnao Pref. LC735301
A. virideventris ♀Minamiashigara-shi, Kanagawa Pref. LC735302
A. virideventris ♀Minamiashigara-shi, Kanagawa Pref. LC735303
A. ejusmodi ♀Yamakita-machi, Kanagawa Pref. LC735304
A. ejusmodi ♀Yamakita-machi, Kanagawa Pref. LC735305
A. yoshitomii ♂Chichijima, Tokyo LC735306
A. yoshitomii ♀Hase-dam, Chichijima, Tokyo LC735307
A. yoshitomii ♀Hase-dam, Chichijima, Tokyo LC735308
A. yoshitomii ♂Hase-dam, Chichijima, Tokyo LC735309
A. variegatus ♀ Isehara-shi, Kanagawa Pref. LC735310
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