Caenis urupa Nascimento & Cruz & Lima & Lima & Hamada & Ale-Rocha 2023, sp. nov.
Creators: name: Nascimento, Stênio R. S.
name: Cruz, Paulo V.
name: Lima, Lucas R. C.
name: Lima, Cláudia R. T.
name: Hamada, Neusa
name: Ale-Rocha, Rosaly
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Ephemeroptera
Caenidae
Caenis
Caenis urupa

description: Caenis urupa sp. nov. (Figs. 2A–E, 3, 4A–C, 5A–E, 6A–C, 7A–F, 8A–F, 9A–D)
Type material. Holotype: ♁ imago in alcohol (genitalia on slide) from Brazil, Rondônia State, Ji-Paraná municipality, Urupá River, S11°02’07.8”, W62°08’41.5”, 23.viii.2022, Nascimento, S. R.S., Cruz, P. V., Lima, C. R. T. cols. (INPA-EPH000042). Paratypes: 15 ♁ imagos in alcohol (light trap), same data as holotype (INPA-EPH000043); five ♀ imagos in alcohol (light trap), same data as holotype (INPA-EPH000045); one ♁ nymph in alcohol (mouthparts, legs and opercular gills on slide), same data as holotype (INPA-EPH000044).
Diagnosis. Male: 1) forceps margins slightly sinuous; 2) penis cylindrical (with rectangular outline in ventral view), apically rounded and not laterally projected. Eggs: 1) micropyle linear with narrow and of moderate length micropylar canal, preceded by an scarcely visible oval sperm guide; 2) two polar caps forming a spiral of fine threads with about 13 terminal knobs. Nymph: 1) lateral margins of the pronotum rounded and broader posteriorly; 2) middle and hind coxa semicircular, without projection; 3) fore tarsal claws a row of small denticles basally, middle tarsal claws with six small denticles basally, hind tarsal claws with several small denticles; 4) sternum IX with posterior margin straight.
Description. Male imago. Body length: 2.5–3.0 mm (n= 4); forewing: 2.2–2.4 mm; foreleg: 2.5–2.9 mm; hind leg: 1.5–1.6 mm; cercus: 7.7–8.2 mm.
Ratios. Foreleg 1.6–1.8× the length of hind leg. Ratio of first segment of the foretarsi length to 2nd:3rd:4th:5th = 0.1–0.2:0.3–0.4:0.3–0.5:0.5–0.8. Genitalia: styliger plate length 2.4–2.8× width; forceps length 7.2–8.5× width at half length; distance between extreme lateral points of forceps bases to forceps length = 1.2–1.4 mm.
Coloration. Head: light brown shaded with dark in dorsal view (Fig. 2A); venter of head yellowish (Fig. 2D). Antenna: scape and pedicel pale, flagellum grayish (Figs. 2A–C). Thorax. Prothorax light brown translucent shaded with black on lateral margin (Figs. 2A–C). Meso- and metanotum light brown shaded with gray on carinae; mesonotum light brown; pleurae and sterna light brown. Wing. forewings hyaline, veins translucent except C, Sc and Rs grayish. Legs. Foreleg dark brown shaded with black, middle and hind femur with subapical pale marks and apically blackish. Abdomen. Terga pale with abdominal segments I–II with a grayish band on medial area and darker laterally, segments III–VI grayish medially, segments VII–VIII yellowish medially and darker laterally, segment IX slightly grayish medially, segment X yellowish (Fig. 2A). Sterna pale with segments VII–IX yellowish (Fig. 2B). Pleura pale (Fig. 2B). Genitalia. Sternum IX with strongly colored sclerites (Figs. 2B, C). Forceps dark brown, penis yellowish (Figs. 2C, E). Caudal filaments pale translucent. (Figs. 2A–C).
Morphology. Antenna: Base of antennal flagellum dilated. Thorax. Pronotum with lateral margins of the pronotum rounded and broader posteriorly (Fig. 2A); prosternal longitudinal ridges forming a triangle shaped structure, closed anteriorly and with straight lateral margins (Fig. 2D). Abdomen. Lateral filaments and fingerlike process on tergum II lacking. Genitalia. Styliger plate sclerotized, length 2.4–2.8× width, anterior margin almost straight and posterior margin straight, covering the basal 1/3 of penis; central sclerite elongate dome-shaped; apophyses long and thin, basolateral sclerites weakly discernible, lateral sclerites slender. Forceps long and slender, progressively tapering towards the apex, with margins slightly sinuosity and not fused to lateral margins of styliger plate. Penis cylindrical and apically rounded (with rectangular outline in ventral view), completely fused and not laterally projected; ventral surface with tubercles and groove (Figs. 2E and 3).
Female imago. Body length: 3.7–4.2 mm (n= 5); forewing: 3.0– 3.2 mm; foreleg: 1.9–2.1 mm; cercus: broken off. Thorax: same as males except mesonotum with more evident dark brown sutures, anterior margin brownish and grayish medially (Fig. 4A); katepisternum shaded with gray while mesopleural sclerites are light brown (Fig. 4B). Abdomen: same as males except abdomen with segments I grayish medially; abdominal sternum IX with posterior margin straight, not projected (Figs. 4A, C). Lateral filaments absent.
Egg. Length: 104–119 μm; width: 79–88 μm. Coloration yellowish. Oval-shaped with length 1.2–1.4 × width. Chorion surface with small pores (Fig. 5B). Micropyle linear with narrow and of moderate length micropylar canal, preceded by a scarcely visible oval sperm guide (Figs. 5A, C). Two polar caps forming a spiral of fine threads with about 13 terminal knobs (Figs. 5A, C, D).
Description. Mature male nymph. Length: Body, 3.7 mm, cercus, broken off. Ratios: Mouthparts. Width of maxillary palp segment I 1.7× width of segment II; length of maxillary palp segment I 1.6× length of segment II; length of maxillary palp segment I 0.9× length of segment III; length of labrum 0.4× its maximum width. Foreleg. Length of forefemur 3.1× its maximum width.
Coloration and Morphology. Head: Brownish; brownish with black markings on posterior margin of occiput; also shaded black behind eyes; mouthparts light brown. Antenna: Flagellum brownish, pedicel paler (Figs. 6A–C). Posterior margin of head with setae. Mouthparts: Labrum with lateral margins rounded, with long subapical setae over the dorsal surface (Fig. 7A); linguae of hypopharynx medially excavated (Fig. 7B); Mandibles with subapical setae varying in size on inner margin (Figs. 7E, F); right mandible with outer margin with a dorsolateral row of long setae (Fig. 7F). Thorax: Nota brownish with brown sutures. Pronotum with anterior margin light brown, lateral zones shaded with black (Fig. 6A). Mesonotum with brownish macula anterior to wing bud bases, and with medial blackish lines (Fig. 6A). Thoracic sterna brownish (Fig. 6C). Legs brownish, femora with blackish marks on subapical zones and paler basally on median and hind femora; tibiae and tarsi blackish on medial zones (Figs. 6A–C, 8A–C). Fore coxa well-developed without projection, middle and hind coxa semicircular without projection (Figs. 8A–C). Fore coxa with long setae on outer margin, dorsal margin of fore femora with setae robust, varying in size, mostly on apical half, outer margin with simple and robust setae varying in size, setae simple varying in size on basal half of inner margin (Fig. 8A); dorsal margin of the median femora with robust setae, varying in size, mostly on middle region, outer margin with simple and robust setae varying in size on apical half (Fig. 8B); dorsal margin of the hind femora with robust setae, varying in size, mostly on middle region, outer margin with long and robust setae on apical half (Fig. 8C). Tibiae with robust setae on inner margins, varying in size (Figs. 8A–C). All tarsi with one row of robust setae on inner margin (Figs. 8A–C). Fore tarsal claws a row of small denticles basally, middle tarsal claws with six small denticles basally, hind tarsal claws with several small denticles (Figs. 8D–F). Abdomen: Terga brownish; segments I–II with a grayish band on medial area and darker laterally; segments III–VI grayish medially, segments VII–VIII brownish medially and darker laterally, segment IX slightly grayish medially, segment X brownish (Fig. 9A). Sterna light brown, with only small grayish medial and lateral marks (Fig. 6C), tergum II with small median projection on posterior margin, triangular with rounded tip. Operculate gills brownish, almost completely shaded with black and laterally with two blackish spots (Figs. 6A, 9C). Operculate gills with submarginal ventral, microtrichia elongated shape and fringed apically, medial Y-ridge complete and well developed; dorsal surface smooth with long, simple setae (Fig. 9C). Posterolateral projections on abdominal segments III–VI long and pointed (Fig. 9A). Sternum IX with posterior margin straight, laterally posteriorly with long simple setae (Fig. 9B). Caudal filaments brownish (Figs. 6A–C, 9A).
Life cycle association. Male genitalia extracted from mature nymph and compared with the male imagos (Fig.
9B).
Etymology. The name of the species is in memory of the extinct native Urupá population that lived on the banks of the river formerly called Ji-Paraná. It has been considered extinct since the beginning of the 20th century, due to territorial disputes with other tribes, but above all to the strong colonizing presence that led to slave labor and the spread of various diseases, with their descendants being culturally eradicated around 1918. The specific epithet is a noun in apposition.
description: Published as part of Nascimento, Stênio R. S., Cruz, Paulo V., Lima, Lucas R. C., Lima, Cláudia R. T., Hamada, Neusa & Ale-Rocha, Rosaly, 2023, New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Rondônia State, Northern Brazil, pp. 237-255 in Zootaxa 5339 (3) on pages 239-247, DOI: 10.11646/zootaxa.5339.3.2, http://zenodo.org/record/8309014