Megabranchiella longusa Phlai-ngam & Tungpairojwong, 2022

Tong, Xiaoli, Zhou, Zhiheng & Wu, Bangyi, 2024, First contribution to the genera Branchiobaetis and Megabranchiella (Ephemeroptera, Baetidae) in China, with descriptions of two new species, ZooKeys 1216, pp. 115-148 : 115-148

publication ID	https://doi.org/ 10.3897/zookeys.1216.129803
publication LSID	lsid:zoobank.org:pub:2312FE20-8C12-48B2-8D97-CFC920CCF5C2
DOI	https://doi.org/10.5281/zenodo.13983554
persistent identifier	https://treatment.plazi.org/id/7B0507CD-1453-55E5-BE24-83370FC43629
treatment provided by	ZooKeys by Pensoft
scientific name	Megabranchiella longusa Phlai-ngam & Tungpairojwong, 2022
status

Treatment

Figs 18 View Figure 18 , 19 View Figure 19 , 20 View Figure 20 , 21 View Figure 21

Megabranchiella longusa : Phlai-ngam & Tungpairojwong in Phlai-ngam et al. 2022: 16 View Cited Treatment .

Material examined.

One female larva on slide; Yunnan, Lushui, Bajiao River (a tributary of the Nujiang River, altitude 1112 m); 21. iii. 2019; leg. Xiaoli Tong .

Diagnosis.

Female larva (Fig. 18 a – d View Figure 18 ), body short and flattened, length ~ 4.0 mm; body colour pattern as Fig. 18 a – c View Figure 18 . Head. Labrum nearly semicircular, ~ 1.4 × wider than long; anteromedian notch deep with a small, rounded lobe at base; dorsal surface in distal 1 / 2 with one pair of long, simple setae near midline and irregular row of three medium, simple setae (Fig. 19 c View Figure 19 ). Left mandible (Fig. 19 a View Figure 19 ), incisor and kinetodontium fused, incisor with four denticles, kinetodontium with six denticles decreasing in length, prostheca robust, apex with six bluntly denticles and one or two long, spine-like denticles; incisor of right mandible with four denticles, kinetodontium with four denticles, inner margin of innermost denticle with row of small denticles; prostheca robust, apex with comb-like structure, with many denticles apically (Fig. 19 b View Figure 19 ). Maxilla (Fig. 19 e View Figure 19 ), galea-lacinia of with three robust canines, base of lacinia with one row of four long, simple setae and one seta perpendicular to lacinia margin; maxillary palp 2 - segmented, apex of segment II with a small cone-shaped projection. Labium (Fig. 19 d, f View Figure 19 ), glossae shorter and narrower than paraglossae, paraglossae with three rows of long curved setae distoventrally, dorsal surface on distal 1 / 2 with one longitudinal row of two or three long, spine-like setae near inner margin; labial palp 3 - segmented, segment I longer than segments II and III combined, segment II triangular with small protuberance apico-laterally, dorsal surface of segment II with row of two robust, simple setae near distal margin (Fig. 19 g View Figure 19 ). Thorax. Hindwing pads reduced (Fig. 20 b View Figure 20 ). Forelegs (Fig. 21 c View Figure 21 ), femur with a row of long, robust, pointed setae along dorsal margin, surface with notched scales anteromedially (Fig. 20 c View Figure 20 ), villopore present (Fig. 20 d View Figure 20 ); tibia with a row of long, pointed setae and short, blunt spatulate setae, tibio-patellar suture present; ventral margin of tarsus with one row of four robust, spine-like setae; claws hooked (Fig. 21 b View Figure 21 ) with one row of 13 acute teeth, subapical setae absent. Middle and hind legs similar to foreleg in structure. Abdomen. Abdominal tergites and sternites with smooth posterior margins (Fig. 21 a View Figure 21 ); gills present on abdominal tergites I – VII, gill I oriented ventrally, extremely enlarged and elongated (Fig. 20 a View Figure 20 ), covering abdominal sternites II – VI (Fig. 18 c View Figure 18 ), gills II – VII oriented dorsolaterally, elongated oval similar to tongue blade (Figs 18 c View Figure 18 , 20 a View Figure 20 ), gill margins with long, fine, hair-like setae, ratio of gill length from I – VII = 3.2: 1.7: 1.7: 1.7: 1.5: 1.3: 1.0; paraproct with smooth margin, without marginal spines or spatulate setae, surface with micropores and patch of notch scales (Fig. 21 d, e View Figure 21 ).

Distribution

(Fig. 23 View Figure 23 ). Thailand (Chiang Mai and Nan Provinces) and China (Yunnan Province).

Larval habitat

(Fig. 22 c View Figure 22 ). The species was collected in a swift, unshaded stream with cobble substrate at an altitude of ~ 1100 m in Yunnan, China.

Remarks.

Geographically, this record represents the farthest distribution north of the genus Megabranchiella so far. We expect that more species of the genus will be discovered with the expansion of the investigation range in China.