taxonID	type	description	language	source
0A6687B89C764114B6BF471EED5AFE29.taxon	description	(Figs. 2 – 8)	en	Oliveira, Laura Almeida De, Corrêa, Amanda Da Silva, Lima, Lucas R. C., Couceiro, Sheyla R. M. (2025): Life stages of Brasilocaenis mendesi Malzacher, 1998 (Ephemeroptera: Caenidae) with redescription of male imago. Zootaxa 5692 (3): 506-518, DOI: 10.11646/zootaxa.5692.3.4, URL: https://doi.org/10.11646/zootaxa.5692.3.4
0A6687B89C764114B6BF471EED5AFE29.taxon	diagnosis	Diagnosis. This species can be characterized by the following combination of characters, male imago: 1) Body length 1.33 – 2.08 mm; 2) Base of antennal flagellum not dilated; 3) Forceps apically pointed, abruptly narrowing at the apex and slightly curved inward; basal half fused to the lateral margins of the styliger plate (Fig. 3 A – D); 4) Styliger plate as wide as long, with a deep median emargination forming two long lateral lobes (Fig. 3 A – D); 5) Presence of a dorsal structure associated with the penis (Lima et al. 2019). Nymph: 1) Anterolateral corners of pronotum pointed (Fig. 6 A); 2) Middle coxa with well-developed semicircular projection, hind coxa with finger-like projection (Fig. 8 B – C); 3) Hind tarsal claws with 14 small denticles (Fig. 8 F); 4) Opercular gill with dorsal surface covered with microspines and short, simple bristles (Fig. 6 C); 5) Sternum IX with a truncated posterior margin.	en	Oliveira, Laura Almeida De, Corrêa, Amanda Da Silva, Lima, Lucas R. C., Couceiro, Sheyla R. M. (2025): Life stages of Brasilocaenis mendesi Malzacher, 1998 (Ephemeroptera: Caenidae) with redescription of male imago. Zootaxa 5692 (3): 506-518, DOI: 10.11646/zootaxa.5692.3.4, URL: https://doi.org/10.11646/zootaxa.5692.3.4
0A6687B89C764114B6BF471EED5AFE29.taxon	description	Descriptions Male imago (Figs. 2 – 3). Length (in mm): Body 1.3 – 2.0 (n = 6); forewing: 1.4 – 2.0; foreleg: 1.1 – 2.2; hind leg: 1.0 – 1.6; cercus: 4.8 – 6.6. Ratios. Foreleg 1.1 – 1.3 × the length of hind leg. Ratio of first segment of the foretarsi length to 2 nd: 3 rd: 4 th: 5 th = 0.2: 0.4 – 0.5: 0.5: 0.7 – 0.8. Genitalia: styliger plate length 0.47 – 0.70 × width; forceps length 6.7 – 7.4 × width at half length. Coloration. Head light brown to yellowish, shaded with dark markings in dorsal view (Fig. 2 A); ventral surface yellowish (Fig. 2 C). Antennae: scape pale; pedicel pale with dark brown apex; flagellum grayish, with basal half dark brown (Fig. 2 A). Thorax. Prothorax light brown to yellowish, with black lateral margins. Meso- and metanotum light brown to yellowish, shaded with brown on the keels; pleura and sterna pale light brown. Wings. Forewings hyaline; veins translucent, except C, Sc, Rs, and MA, which are black. Legs. Yellowish brown, with femora and tibiae each bearing a black subapical spot. Abdomen. Terga whitish: segments I – II with a black medial stripe and darker lateral areas; segments III – VI whitish with subtle black pigmentation medially; segment VII whitish, faintly yellowish, with black lateral spots; segment VIII similar, but lateral black spots are more subtle; segments IX – X faintly yellowish (Fig. 2 A). Sterna pale, with segment IX yellowish (Fig. 2 C); pleura pale (Fig. 2 B). Genitalia. Sternum IX with distinctly yellow sclerites (Fig. 2 C). Forceps dark brown; penis yellowish (Figs. 3 A – D). Caudal filaments. Light and translucent. Morphology. Antenna: Base of antennal flagellum dilated. Thorax. Pronotum with lateral margins rounded and broader posteriorly (Fig. 2 A); process on mesonotal membrane in lateral view triangular, pointed (shark-finshaped) (Figs. 2 B, E); prosternal longitudinal ridges forming a triangular structure, closed and rounded anteriorly and with straight lateral margins (Fig. 2 D). Abdomen. Lateral filaments and fingerlike process on tergum II lacking. Genitalia. Styliger plate sclerotized, with roundly projected lateroposterior margins, forming a variable broad and concave posterior margin in-between. Anterior margin roundly indented between the long and thick apophyses (Fig. 3 A – D), barely discernible basolateral and central sclerites, wide lateral sclerite. Forceps middle third fused with styliger plate, tapering progressively towards apex and curving slightly inwards; smaller, subequal or larger than styliger plate. Penis protruding dorsally and laterally, with apical notch, deeper in some individuals, with sclerotic penile fold. Female imago (Figs. 4 A – E, 5 A – C). Body length: 2.3 – 2.9 mm (n = 7); forewing: 1.9 – 2.1 mm; foreleg: 1.3 – 1.4 mm; cercus, broken. Thorax: Similar to that of males, but with more evident dark brown spots on the mesonotum and metanotum. The process on the mesonotal membrane is less elevated and less developed compared to males. Katepisternum pale yellow; mesopleural sclerites brown (Fig. 4 B). Abdomen: similar to that of males, but with a distinct black line on the posterior margin of terga VII and VIII, more pronounced in some individuals. Abdominal sternum IX with the posterior margin slightly projected (Fig. 4 C). Lateral filaments absent. Egg (Figs. 5 A – C). Length: 97 – 101 μm; width: 64 – 73 μm. Light yellow in color. Oval in shape. Chorion surface smooth. Micropyle funnel-shaped, narrow and elongated, without a sperm guide. Two rope-like polar caps, coiled with fine intertwined threads, located at the narrower end of the egg, each with approximately 12 terminal buttons. Nymph (Figs. 6 A – F, 7 A – F, 8 A – F). Length (in mm): Body, 3.2 – 3.3 mm (n = 2), cercus, broken. Ratios. Mouthparts. Width of maxillary palp segment I 2.4 width of segment II; length of maxillary palp segment I 2.0 × length of segment II; length of maxillary palp segment I 1.3 × length of segment III; length of labrum 0.3 × its maximum width. Foreleg. Length of fore femur 3.0 × its maximum width. Coloration and Morphology. Head. Light brown with black spots, shaded black posterior to eyes; mouthparts light brown to translucent yellowish. Antennae with pedicel and flagellum pale. Labrum broad, with shallow anteromedial emargination and rounded lateral margins; dorsal surface with long bristles along the margin and serrated / denticulate apical edge. Linguae of hypopharynx rounded (Fig. 7 B). Right mandible with subapical bristles of varying size on the inner margin and long, thin setae at the median area (Fig. 7 F). Thorax. Nota light brown with dark brown sutures. Pronotum with light brown anterior margin and black-shaded areas; anterolateral corners pointed (Fig. 6 A). Mesonotum with yellowish white spot anterior to wing bud bases and dark brown medial lines (Fig. 6 A). Thoracic sternum yellowish with brownish outer margins; metasternum with a dark brown posterior line. Legs brownish yellow: femora yellowish-brown with subapical black spots; tibiae yellowish-brown, slightly darkened medially; tarsi yellowish-brown. Fore femur well-developed, without projection; middle and hind femora developed and pointed (Figs. 8 A – C). Coxae without bristles externally; middle coxa with well-developed semicircular projection, hind coxa with finger-like projection. Femora with few, variably sized bristles along dorsal, internal, and external margins (Figs. 8 A – C), anterior and middle femora in the dorsal region with bifid setae (Figs. 8 A – B). Tibiae with simple setae of variable size along the inner margins and with few simple setae on the outer margin (Figs. 8 A – C). Anterior and middle tarsi with a single row of simple setae on the inner margin (Figs. 8 A – C). Hind tarsus with two rows of setae, one simple and the other serrated (Fig. 8 C). Anterior and middle tarsal claws without denticles; posterior tarsal claws with approximately 14 small denticles (Fig. 8 F). Abdomen. Terga light brown, segments I – II with medial black band; III – VI subtly pigmented medially; VII – IX whitish with lateral black spots, more distinct on segment VII; segment X slightly yellowish (Figs. 6 A – B). Sterna light brown to grayish (Fig. 6 B). Operculate gills light brown, nearly entirely shaded with black, and with three lateral black spots; dorsal surface covered by microspines and short, simple setae; medial crest Y-shaped, complete and well-developed; ventral surface with elongated, apically fringed microtrichia (Figs. 6 C – E). Posterolateral projections on segments III – IX long and pointed (Figs. 6 A – B). Sternum IX with a truncated posterior margin, bearing short, simple setae laterally and posteriorly. Caudal filaments brownish (Figs. 6 A – B). Life cycle association. The association was established based on shared morphological characteristics and coloration patterns among specimens collected from the same water body. Although five male imagos of Brasilocaenis elidioi were collected at the same location, the nymphs collected from the same habitat do not match the described morphological characteristics of B. elidioi, indicating that they likely belong to a different species. Additionally, coloration characteristics were used to assist in associating nymphs with adults, the main ones being: yellowish-brown legs; yellowish-brown femora with subapical black spots; and yellowish-brown tibiae, slightly darkened in the median region, patterns that can also be observed in both male and female adults. The alates of Brasilocaenis elidioi generally exhibit a whitish body coloration; however, the specimens we analyzed showed a yellowish hue.	en	Oliveira, Laura Almeida De, Corrêa, Amanda Da Silva, Lima, Lucas R. C., Couceiro, Sheyla R. M. (2025): Life stages of Brasilocaenis mendesi Malzacher, 1998 (Ephemeroptera: Caenidae) with redescription of male imago. Zootaxa 5692 (3): 506-518, DOI: 10.11646/zootaxa.5692.3.4, URL: https://doi.org/10.11646/zootaxa.5692.3.4
0A6687B89C764114B6BF471EED5AFE29.taxon	materials_examined	Material examined. Fourteen ♂ imagos, 2 ♂ subimagos, 1 ♀ imago, 2 ♀ subimagos from Brazil, Pará state, Santarém city, Júa-Casa Stream, 02 ° 26 ’ 4 ” S; 54 ° 47 ’ 21 ” W, 27 – 28. ix. 2023, Oliveira L. A. col. (UFOPA); 100 ♂ imagos, 19 ♀ imagos, from Brazil, Pará state, Mojuí do Campos city, Moju river, 02 ° 42 ’ 03 ” S, 54 ° 41 ’ 01 ” W, 11. xi. 2020, Oliveira L. A. col. (UFOPA); 1 nymph, same data except date 21. i. 2020 (UFOPA); 1 nymph, same data except date 05. vii. 2020 (UFOPA).	en	Oliveira, Laura Almeida De, Corrêa, Amanda Da Silva, Lima, Lucas R. C., Couceiro, Sheyla R. M. (2025): Life stages of Brasilocaenis mendesi Malzacher, 1998 (Ephemeroptera: Caenidae) with redescription of male imago. Zootaxa 5692 (3): 506-518, DOI: 10.11646/zootaxa.5692.3.4, URL: https://doi.org/10.11646/zootaxa.5692.3.4
