Baetiella bispinosa ( Gose, 1980 )

Shi, Weifang & Tong, Xiaoli, 2015, Taxonomic notes on the genus Baetiella Uéno from China, with the descriptions of three new species (Ephemeroptera: Baetidae), Zootaxa 4012 (3), pp. 553-569 : 554-555

Baetiella bispinosa ( Gose, 1980)

( Fig. 45 )

Pseudocloeon bispinosus: Gose, 1980: 211 ;

Baetiella bispinosa: Waltz & McCafferty, 1987: 563 ; Tong & Dudgeon, 2000: 143

Diagnosis. Posterior margin of metanotum and abdominal terga I–II each with a single posteromedian protuberance, terga III–IX each with a pair of protuberances, the distance between protuberances gradually widened backwards, and distance between their bases on tergum III longer than the length of protuberance ( Fig. 45 ). Hind wing pads vestigial. Basis of all legs with a single finger-like white coxal gill (cf. Fig. 49 ); claw with two rows of denticles, outer row with 8–9 acute denticles which successively increasing in length forwardly, inner row medially with 4–5 short and blunt denticles. Gills (or gill sockets) present on terga I–VII ( Fig. 45 ). Median caudal filament reduced to one segment, cerci usually 1.5 times longer than body length.

Material examined. CHINA. Guangdong: 16 nymphs, Yangchun, Bajia Town, Baishuihe River (21.90°N, 111.39°E, alt. 110m), 9.vi.2011, leg. Weifang Shi; 1 nymph on slides, Lechang County, Jiufeng Town (25.34°N, 113.38°E), 2.viii.2011, leg. Huimin Zhong.

Distribution. China (Guangdong, Hong Kong); Japan.

Comments. The specific name of this species first appeared in the diagnostic key to Japanese mayflies given by Gose (1980) who assigned it to the genus Pseudocloeon . However, Gose did not specifically state he was establishing a new species because he was neither designating nor describing the species and only provided a nymphal habitus illustration and some characters for the diagnostic key. According to the current Articles 10–16 and 71–76 of the International Code of Zoological Nomenclature (ICZN 1999), the name Pseudocloeon bispinosus Gose should be regarded as an invalid name. Moreover, because Gose (1980) did not designate type specimens for this species, it should be also considered as nomen dubium. However, based on the second edition of the Code (ICZN 1962), Pseudocloeon bispinosus Gose met the requirements for availability as a valid species because Gose’s paper was published before 1985. Waltz & McCafferty (1987) transferred it to the genus Baetiella . Considering that the name Baetiella bispinosa (Gose) has been traditionally accepted and widely used by mayfly workers, and until a neotype is established, it seems better to keep it as the current name, rather than to erect a nomen novum.

Figures

FIGURES 45 – 54. Baetiella spp. from China. (45) B. bispinosa (Gose); (46 – 47) dorsal and lateral view of B. macani (Muller- Liebenau); (48) B. marginata Braasch; (49) coxal gills of B. macani (Muller-Liebenau); (50) thoracic sterna of B. spathae n. sp.; (51) thoracic sterna of B. tuberculata (Kazlauskas); (52) head and thorax of B. marginata Braasch; (53) B. trispinata Tong & Dudgeon; (54) B. tuberculata (Kazlauskas).