Siphlonurus chankae Tshernova, 1952

Qiang, Xin-He & Zhou, Chang-Fa, 2025, The species diversity and phylogeny of the genus Siphlonurus Eaton, 1868 from China (Ephemeroptera: Siphlonuridae), Zootaxa 5711 (1), pp. 1-56 : 5-8

publication ID	https://doi.org/10.11646/zootaxa.5711.1.1
publication LSID	lsid:zoobank.org:pub:3178B789-303D-448B-9624-6423117DE14F
persistent identifier	https://treatment.plazi.org/id/E57D87B7-FFF4-FFF4-FF71-FC687E2EFC38
treatment provided by	Plazi
scientific name	Siphlonurus chankae Tshernova, 1952
status

Treatment

Siphlonurus chankae Tshernova, 1952 View in CoL

Figures 1–2 View FIGURE 1 View FIGURE 2

Siphlonurus chankae Tshernova, 1952: 263 View in CoL (male and female imago, from Russia).

Siphlonurus chankae View in CoL : Kluge 1985: 13 (adult re-description, lectotype designation); Tshernova et al. 1986: 126 (first record from China); Bae et al. 1994: 44 (catalogue); Bae & Yoon 1997: 50 (catalogue); Hwang & Bae 2001: 45 (first description of nymph); Quan et al. 2002: 257 (list); Bauernfeind & Soldán 2012: 70 (description of nymph and subimago); Zhou 2013: 204 (list); Zhou et al. 2015: 254 (list).

Material examined: 4 nymphs, 1♀ imago, 1♂ imago, Wuying Forest Park, Fenglin County, Yichun City , Heilongjiang Province, 48.204776°N, 129.209142°E, ca. 300 m, 17–20.VII.2024, Dewen Gong and Xuhongyi Zheng ; 3 nymphs, 8♀ imagos, 2♂ imagos, 2♂ subimagos, Laocaohe , Mohe City , Daxinganling District , Heilongjiang Province, 52.833392°N, 122.591656°E, ca. 480 m, 16–19.VII.2024, Xinhe Qiang , Ningning Wang , and Yuxian Sun ; 10 nymphs, 9♀ imagos, Dalin River , Mohe City , Daxinganling District , Heilongjiang Province, 52.968586°N, 122.269555°E, ca. 470 m, 16–19.VII.2024, Xinhe Qiang, Ningning Wang, and Yuxian Sun GoogleMaps .

Description: see Kluge (1985, adult), Hwang & Bae (2001, nymph) and Bauernfeind & Soldán (2012, nymph and subimago).

Distribution: China ( Heilongjiang Province); Korea; Russia; Mongolia.

Diagnosis

Mature nymph: body length ranges from 13.0 to 15.0 mm, wingpads without spots ( Figs 1A, B View FIGURE 1 ). Length ratio of first segment of maxillary palp to galea-lacinia 1.0: 1.0, inner margin of maxillary palp segment II straight ( Fig. 1C View FIGURE 1 ). Posterolateral spines on terga I–IX gradually larger from anterior to posterior, length ratio of posterolateral spine on tergum IX to its tergum = 1.0: 4.0 ( Figs 1D–F View FIGURE 1 ). Each abdominal sternum with inverted U-shaped marking ( Fig. 1B View FIGURE 1 ). Posterior margin of abdominal sternum IX slightly convex ( Figs 1E, F View FIGURE 1 ). Both dorsal surface and posterior margin of tergum X with stout and pointed spine-like setae, lateral margins lack ( Fig. 1G View FIGURE 1 ). Outer margins of dorsal and ventral lamellae of both gills I and II concave, costal rib of dorsal lamella in gill II shorter than half of anterior margin ( Figs 1H, I View FIGURE 1 ). Outer and posterior margins of gill III concave ( Fig. 1J View FIGURE 1 ). Proximal plate of gill VII well developed ( Fig. 1K View FIGURE 1 ).

Male imago: Body length 16.0–18.0 mm, wings transparent. Forelegs entirely brown, midlegs and hindlegs entirely yellowish ( Figs 2A–C View FIGURE 2 ). Each abdominal sternum with an inverted U-shaped marking, posterolateral spines of abdominal segments VIII and IX relatively small ( Figs 2D–G View FIGURE 2 ). Inner margin of basal segment of forceps with projection, length of penis subequal to styliger ( Figs 2D, E View FIGURE 2 ). Dorsal elongation of penis curved with enlarged base and outer margin with about 3 small spines basally, dorsal sclerotized transverse band of penis without expansion, two penis lobes distinctly separated, each with concave tip, ventral side with translucent membranous projection, inner margin with 4–6 small spines, outer margin concave ( Figs 2H–J View FIGURE 2 ).

Female imago: Body length 15.0–17.0 mm, wings transparent. Color pattern similar to male. Each abdominal sternum with inverted U-shaped marking ( Fig. 2K View FIGURE 2 ); sternum VII extended posteriorly into triangular lobe, sternum VIII with pair of depressed funnel-shaped sclerotized line ( Fig. 2 L View FIGURE 2 ).

Remarks. The male genitalia of this species are similar to those of S. immanis because of elongated penal lobe. However, both nymph and adults of them possess distinct diagnostic characteristics. The morphological differences in mature nymph are: (1) this species is significantly smaller than S. immanis ; (2) posterior margin of abdominal sternum IX in this species is slightly convex ( Figs 1E, F View FIGURE 1 ), whereas in S. immanis , it is relatively straight; (3) posterolateral spines of abdominal sterna in this species are relatively small, with a length ratio of spine to sternum of 1.0: 4.0 ( Figs 1D–F View FIGURE 1 ). In contrast, posterolateral spines in S. immanis are larger, with a length ratio to sternum of 1.0: 2.0.

The diagnostic characteristics of male adults mainly differ in: (1) in this species, the dorsal elongation of penis is curved, with an expanded base and approximately three small spines on outer margin ( Fig. 2J View FIGURE 2 ). In contrast, dorsal elongation of penis in S. immanis is slender and smooth, lacking spines; (2) posterolateral spines of abdominal terga VIII and IX in this species are relatively small ( Figs 2D, E View FIGURE 2 ), whereas in S. immanis , these spines are highly developed, being broad and sharply pointed.

Nymph of this species is almost identical in all characteristics to that of S. zhelochovtsevi , except for the maxillary palps (see remarks section of S. zhelochovtsevi ).

Kingdom	Animalia
Phylum	Arthropoda
Class	Insecta
Order	Ephemeroptera
Family	Siphlonuridae
Genus	Siphlonurus