Oxidus riukiaria ( Verhoeff, 1940 )

Anh D. Nguyen, Zoltán Korsós, Kuem-Hee Jang & Ui-Wook Hwang, 2017, A revision and phylogenetic analysis of the millipede genus Oxidus Cook, 1911 (Polydesmida, Paradoxosomatidae), European Journal of Taxonomy 293, pp. 1-22 : 11-12

Oxidus riukiaria ( Verhoeff, 1940)

Figs 5–7

Orthomorpha riukiaria Verhoeff, 1940: 139 , fgs 5−6.

Orthomorpha riukiaria – Takakuwa 1954: 39, fg. 34.

Oxidus riukiarius – Jeekel 1963a: 20.

Oxidus riukiaria – Nguyen & Sierwald 2013: 1295.

Material examined

JAPAN: 4 ♂♂, 4 ♀♀, Central Ryukyus, Okinawa-jima, Ogimi village, Nerome, above road no.58, 26°41′37″ N, 128°06′43″ E, 37 m a.s.l., 25 Sep. 2012, leg. Z. Korsós (IEBR-H470); 2 ♂♂, 2 ♀♀, Okinawa-jima, Yanbaru, Ogimi village, Nunha, Okuni rindo, 26°41′10.1″ N, 128°09′02.7″ E, 15 Sep. 2012, leg. Nakamura Y. (IEBR-H500); 2 ♂♂, Central Ryukyus, Okinawa Island, Yanbaru, Kunigami village, Cape Hedo, Ginama, broad-leaved evergreen forest, 176 m, 26°49′52″ N, 128°16′20″ E, 5 Apr. 2011, leg. Z. Korsós (HNHM-355); 1 ♂, Northern Ryukyus, Tokara group, Kuchino-shima Island, around Kuroshio-so guesthouse, 29°59′24″ N, 129°55′21″ E, 63 m, 14 Oct. 2012, leg. Z. Korsós (HNHM-477).

Other records (newly found ones underlined)

JAPAN: Northern Ryukyus, Tokara Group: Kuchino-shima Island; Central Ryukyus: Okinawa-jima, Kume-jima, Iheya-jima, Aguni-jima, Zamami-jima, Aka-jima, Geruma-jima (observations by Z. Korsós).

Diagnosis

Oxidus riukiaria can be distinguished from all other species of Oxidus by its smaller size (19.3−20.6 mm in length, width of pro- and metazonae 1.5−1.8 mm and 2.1−2.2 mm); gonopod coxae more or less stouter and longer than femorite; femorite narrow at base, and strongly expanded towards distal end; gonopod process h hook-like, larger and getting narrower towards pointed tip, spine z small, pointed spiniform; postfemoral lamina l triangularly rounded; mesal lobule not seperated from solenophore tip, which is distinctly emarginated.

DNA

COI and 16S barcode data (partial) are deposited in GenBank ( Table 1).

Remarks

This species was originally described by Verhoeff (1940) in the genus Orthomorpha , but was assigned to Oxidus by Jeekel (1963a). The taxonomic position of the species is also well supported by molecular data.

Distribution

South Japan (Ryukyu Islands).

Figures

Fig. 5. Oxidus riukiaria (Verhoeff, 1940) from Okinawa, Japan. A. Entire body, length ca 20 mm. B – C. Segments 8 – 9 – 10. B. ♂. C. ♀. Scale bars = 1 mm. (photos by Z. Korsós)

Fig. 6. Left gonopod of Oxidus riukiaria (Verhoeff, 1940). A. Lateral view. B. Postfemoral region, lateral view. Redrawn from Verhoeff 1940. No scale bars.

Fig. 7. Left gonopod of Oxidus riukiaria (Verhoeff, 1940), from sample IEBR-H 470. A. Lateroventral view. B. Ventral view. C. Postfemoral region, ventral view. Note: z = spine z, but broken.