identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
F1D31B7E048553BBABB3D7252C5C78D7.text	F1D31B7E048553BBABB3D7252C5C78D7.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Ephoron yunnanensis Zhou 2026	<div><p>Ephoron yunnanensis Zhou sp. nov.</p><p>Figs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20</p><p>Ephoron yunnanensis Zhou, 2002 (nomen nudum) (in doctoral dissertation).</p><p>Material examined.</p><p>Holotype: China • 1 male imago, Yunnan Province, Jinggu County, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=100.140205&amp;materialsCitation.latitude=23.19836" title="Search Plazi for locations around (long 100.140205/lat 23.19836)">Fengshan village</a>; 23°11'54.10"N, 100°8'24.75"E; 8. IV. 2001, ZHOU Chang-Fa leg. (NJNU Mayfly 2607171) . Paratypes: China • 3 male imagos, 10 female subimagos, 5 nymphs, same data as for holotype (NJNU Mayfly 2607172) .</p><p>Other materials.</p><p>China • 2 male imagos, Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Menglun County, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=101.25093&amp;materialsCitation.latitude=21.93463" title="Search Plazi for locations around (long 101.25093/lat 21.93463)">Nanban River</a>, 21°56'4.67"N, 101°15'3.36"E, 542 m a. s. l., 25. I. 2023, Xuhongyi Zheng leg. (NJNU Mayfly 2607173) . Thailand • 105 subimagoes, 12 nymphs, Chiang Mai Province, Chang Khoeng, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=98.35667&amp;materialsCitation.latitude=18.512777" title="Search Plazi for locations around (long 98.35667/lat 18.512777)">Mae Chaem River</a>, 470 m a. s. l., 18°30'46"N, 98°21'24"E, 15. XII. 2024, B. Boonsoong, S. Kwanboon, C. Auychinda leg. (ZMKU Ephe-048) . THAILAND • 7 nymphs, Chiang Rai Province, <a href="https://tb.plazi.org/GgServer/search?materialsCitation.longitude=99.77195&amp;materialsCitation.latitude=19.930637" title="Search Plazi for locations around (long 99.77195/lat 19.930637)">Mae Kok River</a>, 398 m a. s. l., 19°55'50.3"N, 99°46'19.0"E, 01. IX. 2019, B. Boonsoong, S. Kwanboon, C. Auychinda leg. (ZMKU Ephe-049) .</p><p>Diagnosis.</p><p>The nymphs of Ephoron yunnanensis sp. nov. can be separated from those of other Ephoron species based on the following characteristics: i) blunt small spine between outer and inner incisors on right mandible (Fig. 3 B), ii) frontal process triangular (Fig. 1 A), iii) abdominal gill without lateral pigmented branch (Fig. 6 B). In male imago, six intercalary veins in CuA field of forewing (Fig. 6 A), colour pattern of abdominal terga (Fig. 7 A), five, four, and four tarsomeres in foreleg, midleg, and hindleg respectively; moderately deep median cleft of penis (Fig. 10 A, B). In female subimago, legs poorly developed, with forelegs 4 - segmented, other legs 3 - segmented, and egg oval with a smooth chorion (Fig. 14 A, C).</p><p>Description.</p><p>Nymph (in alcohol): body length 9.7–15 mm (n = 5), caudal filaments shorter than body length (Fig. 1 A, B). Coloration. Head. Brownish, dark brownish between ocelli. Antenna pale yellowish. Compound eye black, ocelli white, inner margin of ocelli black. Mouthparts pale brown. Thorax. Brown as in Fig. 1 A. Legs whitish to yellowish. Abdomen. Brown, with dark brown markings along the terga. Sterna whitish. Gills whitish to yellow. Caudal filament uniformly yellowish.</p><p>Head. Prognathous, trapezoidal in dorsal view, anterior margin with a triangular frontal process (Fig. 1 A).</p><p>Mouthpart. Labrum rounded, ca 1.5 times wider than long, covered with numerous hair-like setae in dorsal surface (Fig. 4 A). Mandibular tusk yellowish to golden, apex brown and slightly curve inward; tusk cover with dense setae in dorsal base, over 17 brownish tubercles on dorsal and lateral margin (Fig. 2 A, B); only right mandible with small, reduced spine between outer and inner incisor (Fig. 3 A, B). Labium covered with dense setae, paraglossae and glossae drop shape with numerous setae, labial palpi 2 - segmented, segment I shorter than segment II, both covered with setae (Fig. 4 D). Maxilla stout, with relatively broad, subrectangular, crown covered with dense setae, distal margin simple without denticles; maxillary palpi 2 - segmented, first segment shorter than second segment, second segment similar in shape to the second segment of labial palp (Fig. 4 B, D). Hypopharynx broad, with well-developed superlinguae; each superlingua rounded and densely covered with long, hair-like setae. Lingua narrow, distinctly shorter than superlinguae, apical margin rounded (Fig. 4 C).</p><p>Thorax. Dorsal and ventral surfaces covered with long, fine, yellowish setae. Forelegs strongest, stout and fossorial with several distinct rows of long simple setae; ventral margin of femora with a basal row of tubercles; tibiae flattened, inner margin with two rows of tubercles; tarsal claws hooked and stout (Fig. 5 A – C), tibia and tarsus much wider than in midleg and hindleg, length ratio of femur: tibia: tarsus ca 1.0: 1.3: 0.3. Midleg shortest, similar in structure to foreleg, length ratio of femur: tibia: tarsus ca 1.0: 1.1: 0.4. Hindleg similar in structure to foreleg, length ratio of femur: tibia: tarsus ca 1.0: 1.2: 0.5.</p><p>Abdomen. gills on abdominal segments I – VII, with black dot at base of gills II – VII, gill I uniramous, banana-shaped (Fig. 6 A); gills II – VII similar in shape, biramous, both lamellae fringed with hair-like setae, dorsal lamella slender and slightly curved, outer margin with a shallow depression medially, expanded basally, without lateral pigmented branch (Fig. 6 B). Cerci and paracercus subequal in length, with setae.</p><p>Male imago (in alcohol): body length 10–13 mm (n = 5). caudal filaments longer than body length. Colouration. Head. yellowish to brownish, dark brown between ocelli. Antenna whitish, darker at base. Compound eye black, ocelli white, inner margin of ocelli black. Thorax. Yellowish with brown markings (Fig. 7 A). Abdomen. Abdominal terga whitish, with dark-brownish markings becoming darker and wider posteriorly, and darkest on segments VIII – X (Fig. 7 A, C). Abdominal sterna whitish without markings (Fig. 7 B).</p><p>Head. Head width slightly less than pronotum width (Fig. 7 A). Compound eye globular on posterolateral margin of head.</p><p>Thorax. Foreleg well developed and slender, five segments of tarsomeres, length ratio of femur, tibia and five tarsomeres ca 1: 4: 0.2: 1.3: 1.0: 1.0: 0.6, claws paired, rounded apically. Midleg and hindleg greatly reduced and much shorter than foreleg (Fig. 8 A – C). Midleg shortest, length ratio of femur, tibia, and tarsus ca 1: 1.1: 0.4, tarsus with paired claw, length ratio of tarsomeres ca 0.1: 0.1: 0.2. Hindleg similar midleg in shape but longer, length ratio of femur, tibia, and tarsus ca 1: 1.2: 0.4, length ratio of tarsomeres ca 0.2: 0.1: 0.1. Forewings hyaline ca 10.5 mm in length, costal margin slightly brownish, apical and cubital angle rounded, numerous cross-veins (Fig. 9 A). Fork of MA distal to fork of RS, 1 intercalary between MA 1 and MA 2. RS forked at basal 1 / 4 with five intercalaries in RS fork. MP asymmetrical forked at base. CuA forked, with six intercalaries between CuA 1 and CuA 2; CuP and CuA 2 parallel; A 1 straight (Fig. 9 A). Hindwings ca 0.5 × forewing in length, hyaline, with a blunt costal-basal projection; one intercalary between RA and RSa, RS fork at middle of wing; MA single, MP fork symmetrically near 1 / 3 of base wing; 3 intercalaries between CuA and CuP (Fig. 9 B).</p><p>Abdomen. Genitalia with four elongated segmented forceps, first and second segments similar in length, third segment longest. Penis diverging laterally and hook and the apex of each lobe, subapical margin distinctly concave, apices rounded, moderately deep median cleft (Fig. 10 A, B).</p><p>Female subimago (in alcohol): Body length 12.8–15.3 mm (n = 5) excluding caudal filament and cerci. Sexually mature in this stage.</p><p>Colouration. Head. Markings and colour similar to male (Fig. 11 A). Thorax. Colour and pattern same as male. Abdomen. Abdominal terga whitish, with dark-brownish markings becoming darker and wider posteriorly, and darkest on segments VIII – X (Fig. 11 A – C). Abdominal sterna whitish without markings (Fig. 11 B).</p><p>Thorax. Foreleg poorly developed, four segments of tarsomeres, length ratio of femur, tibia tarsus and four tarsomeres ca 1.0: 1.2: 0.4: 0.1: 0.1: 0.1, claws paired, rounded apically (Fig. 12 A). Midleg shortest, femur: tibia: tarsus ratio 1.0: 1.1: 0.4, three segments of tarsomeres, length ratio ca 0.1: 0.1: 0.2 (Fig. 12 B). Hindleg slightly longer than midleg, femur: tibia: tarsus ratio 1.0: 1.0: 0.3, tarsus three segmented, length ratio ca 0.1: 0.1: 0.1 (Fig. 12 C). Forewings ca 19 mm in length, translucent, costal margin slightly brownish, overall shape and venation comparable to male, except for the presence of five intercalary veins between CuA 1 and CuA 2 (Fig. 13 A). Hindwings translucent, costal projection well developed, venation similar to male (Fig. 13 B).</p><p>Abdomen. Cerci and paracercus subequal in length, shorter than body length, covered with setae.</p><p>Egg. Dissected from female subimago; length 282–328 μm, width 183–224 μm (n = 5); Elongate-oval, with one large polar cap (Fig. 14 A, B); polar cap irregular in outline, occupying ca 1 / 3 of egg length, its margin distinctly separated from main chorion; chorion smooth, without any reticulation (Fig. 14 C); opposite pole slightly tapering, without a concave depression; one visible micropyle situated beneath polar cap (Fig. 14 D). Eggs tightly grouped together form two elongate-oval, yellow egg masses, hard in air, sticky after contact with water (Figs 11 C, 18 D).</p><p>Description of the first instar.</p><p>Egg masses of E. yunnanensis were immersed in water under laboratory conditions; polar caps of egg facilitated attachment to substrate (Fig. 15 A). Embryonic development complete and hatching after 12 days. E. yunnanensis hatches from its egg case at the uncapped pole, the chorion opens in a circular manner as in Fig. 15 B. Body length of first instar 560–680 μm (Fig. 16 A – C). Mouthparts. Mandibles of first instar large compared to head capsule size; in distal region of mandible, mandibular tusk begins to develop, located perpendicular (ca 90 °) to canine region, apex pointing toward canine region; distal-most tips of mandibular tusks modified into small teeth in canine region (Fig. 17 A). Maxillae bare, with small tooth structure; galea lacinia fused; palps unsegmented (Fig. 17 A). Labium with short palp, with four lobes between palp corresponding to two outer paraglossae and two inner glossae (Fig. 17 A). Labrum rounded, with four or five short setae (Fig. 17 A). Thorax. All legs present: coxae, trochanters, femora, tibiae, tarsi, and claws already differentiated. Legs sparsely setose (Fig. 16). Abdomen. Gill absent (Fig. 17 B). Three caudal filaments present.</p><p>Etymology.</p><p>The specific epithet yunnanensis refers to Yunnan Province, where the type locality is located.</p><p>Biology.</p><p>In Thailand, the mass emergence of E. yunnanensis typically began around 19.00 and finished approximately at 20.30 (GMT + 7). Both sexes were attracted by a light trap set near the Mae Chaem River, as observed on 29 March 2025 (Fig. 18 A). Among the emerging individuals, mostly female subimagoes were found (Fig. 17 B, D). The sex ratio (female to male) was 2: 1. The female subimagoes were observed fluttering their wings over the rocky substrate adjacent to the streambank, attempting to oviposit (Fig. 17 C, D). The egg bar appeared as a yellowish rod-like structure (Fig. 17 D). The female typically dies shortly after oviposition. However, no mating behaviour between males and females was observed during this survey.</p><p>Distribution.</p><p>China (Yunnan Province) and Thailand (Chaing Mai and Chiang Rai Provinces) (Fig. 20).</p><p>Molecular analysis.</p><p>The partial sequences of the mitochondrial COI gene (658 bp) of the E. yunnanensis sp. nov. from China and Thailand were obtained from specimens of each locality. In addition, other Ephoron species were combined to investigate species delineation (Table 1). The K 2 P analysis revealed that the mean intraspecific genetic distance among Thai and Chinese populations of E. yunnanensis sp. nov. is 2.52 %, and for E. debaratana 2.88 %. The mean interspecific distances between Ephoron are high, ranging from 4.60 % to 26.84 % (Table 2). The interspecific genetic distances among the Thai species of Ephoron ranged from 20.37 % to 22.10 %. Pairwise genetic distances were 20.37 % between E. yunnanensis sp. nov. and E. ookaewae, 20.78 % between E. debaratana and E. ookaewae, and 22.10 % between E. yunnanensis sp. nov. and E. debaratana .</p><p>The maximum-likelihood (ML) analysis of COI supports the monophyly of three Thai species (Fig. 19). The newly obtained sequences of E. yunnanensis sp. nov. formed a distinct and well-supported monophyletic clade, clearly separated from its congeners. Within E. yunnanensis sp. nov., the Thai and Chinese specimens clustered together with strong nodal support. Ephoron yunnanensis sp. nov. was inferred as a sister lineage to E. ookaewae, while E. debaratana formed a separate distant clade, separated from the other Thai species. Additionally, the Japanese species; E. eophilum, E. shigae, and E. limnobium formed a distinct monophyletic clade. The ASAP species delimitation analysis identified nine molecular clusters, with E. yunnanensis sp. nov. recovered as a distinct operational taxonomic unit (OTU) separate from all other congeners, consistent with the ML topology (Fig. 19).</p></div>	https://treatment.plazi.org/id/F1D31B7E048553BBABB3D7252C5C78D7	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Pensoft via Plazi	Kwanboon, Sedtawut;Zheng, Xu-Hong-Yi;Zhou, Chang-Fa;Boonsoong, Boonsatien	Kwanboon, Sedtawut, Zheng, Xu-Hong-Yi, Zhou, Chang-Fa, Boonsoong, Boonsatien (2026): Taxonomic validation of Ephoron yunnanensis Zhou, 2002 (nomen nudum) (Ephemeroptera, Polymitarcyidae). ZooKeys 1286: 227-250, DOI: 10.3897/zookeys.1286.204617
