Miroculis (Ommaethus) misionensis Domínguez 2007 Figures 8; 12 Miroculis (Ommaethus) misionensis Domínguez, 2007: 99 (male and female imago). Diagnosis. The nymph of Miroculis (O.) misionensis differs from the remaining species of Miroculis by the following combination of characters: 1) labrum with anterolateral margin rounded; 2) maxilla with 53 pectinate setae along subapical margin; 3) posterolateral spines on abdominal segments V–IX, more developed from VII to IX; and 4) gills broad, with the lateral lobes present and trachea unbranched. Description. Mature nymph (exuviae)—in alcohol. MEASURES (mm). Body: 5.9. Thorax: fore leg: 3.0; middle leg: 2.8; hind leg: 3.1. RATIOS. Mouthparts: segment III of maxillary palp 0.3× segment II; segment II 1.2× segment I; segment III of labial palp 0.5× segment I; (segment I of labial palp damaged). Legs: width of fore femur 0.4× length; width of hind-femur 0.4× length. Abdomen: width of lamella of gill in its wider part 0.17× length of gill (Fig. 12); length of medial filament of gill 0.8× length of gill body. COLORATION. Body. Thorax: pattern of marks as in male imago, with posterior margin of all segments dark, terga II–VII with U-shaped lateral marks on each segment and tergum VII with submedial longitudinal lines. Legs: pattern of marks as in male imago, except for sub-basal band on tibiae; femora with no subapical marks on dorsal and ventral surfaces. Abdomen: pattern of marks as in male imago (Domínguez, 2007). Gills with inner margin of membrane darker than outer margin. MORPHOLOGY. Head: clypeus anteriorly concave; anterolateral margin of labrum rounded (Fig. 8); maxilla with 53 pectinate setae along subapical margin. Abdomen: posterolateral spines present on segments V–IX, more developed on VII–IX. Gills broad, with lateral lobes present and length of inner and outer margin of lamella subequal; with trachea unbranched (Fig. 12). Male imago. Properly described by Domínguez (2007) with the additional information: RATIOS. Forceps with segment III 0.9 × segment II; forceps with segment II 0.4 × segment I; styliger plate with lateral length 0.5 × medial width; penis length 0.8 × length of forceps segment I. MORPHOLOGY. Styliger plate with anterior margin straight; forceps segment II darker than segment I; 1/4 basal of forceps segment I broad narrowing abruptly toward apex. Material examined. BRAZIL: Santa Catarina: 1 male imago and nymphal exuviae, Erval Velho municipality, 27°19’54.1’’S, 51°19’21.2’’W, 760m, 18.ix.2011, Pes, A.; Boldrini, R.; Cruz, P.; Hamada, N. col, reared. Distribution. ARGENTINA: Misiones. BRAZIL: Santa Catarina. Biological aspects. Originally collected in a protected area (Parque Provincial de Urugua-í, Misiones, Argentina; Domínguez 2007; Manzo et al. 2014), and in low altitudes (from 271 to 410 m.a.s.l.), the nymph collected in Brazil was found in a medium order river surrounded by agricultural areas with relatively higher altitude (760 m. a.s.l.). The substrate was rocky and with particulate organic matter. The species, so far, is distributed in the Atlantic Forest biome.

Published as part of Raimundi, Erikcsen Augusto, Domínguez, Eduardo & Salles, Frederico Falcão, 2021, Description of a new species, nymphs of two known species and a new record of Miroculis Edmunds, 1963 (Ephemeroptera: Leptophlebiidae) from Brazil, pp. 384-392 in Zootaxa 4963 (2) on pages 390-391, DOI: 10.11646/zootaxa.4963.2.9, http://zenodo.org/record/4701027