New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil Nascimento, Stênio R. S. Rodrigues, Jackson A. O. Ale-Rocha, Rosaly Lima, Lucas R. C. Zootaxa 2022 2022-05-03 5133 1 110 122 62JGW 197147 Stephens, 1836 Stephens 1836 [349,432,1267,1293] Insecta Caenidae Caenis Animalia Ephemeroptera 9 119 Arthropoda genus     1. Apex of the forceps sharp and sclerotized................................................................. 2  - Apex of the forceps rounded........................................................................... 5   2(1). Forceps narrowing gradually toward the apex.............................................................. 3  - Forceps sharpening abruptly at the apex................................................................... 4   3(2). Surface of the forceps without setae with 3 subapical denticles; lobes of the penis fused, without vestige of a dividing groove ( Da-Silva, 1993: Fig. 4)....................................................................  Caenis cuniana  - Forceps generally with small tubercles and setae on outer basal margin; forceps 7.3–9.5 times longer than width at the middle; apophyses strongly developed, wide and long ( Molineri et al. 2011: Figs 3, 5, 6A–F)...................  C. teipunensis   4(2). Forceps approximately six times longer than width at half length; about six setae present on ventral surface ( Malzacher, 1986: Figs 5B, C, 11)............................................................................  C. candelata  - Forceps approximately 9-11 times longer than width at half length, approximately 15-20 setae present on ventral surface ( Malzacher, 1986: Figs 5A, 10)..................................................................  C. fittkaui   5(1). Finger-like median process present in abdominal tergum II; fore leg twice as long as hind leg or longer; forceps and sclerites of the genitalia strongly colored........................................................................... 6  - Abdominal tergum II without median projections (but lateral projections may be present); fore leg at most 1.8 times the length of hind leg; forceps and sclerites of the genitalia nearly uncolored)............................................. 7   6(5). Lateral filaments of abdominal segments relatively short; lobes of penis short and laterally rounded; apophyses of the styliger sclerite long and thin, somewhat distanced from the base of the forceps ( Malzacher, 2001: Figs 7A–E)......  C. plaumanni  - Central sclerite of styliger elongated; apophyses of styliger sclerite broad and short; penis whitish with rounded lateral lobes ( Molineri & Malzacher, 2007: Figs 96–98)..........................................................  C. uruzu   7(5). Lobes of the penis totally fused, without a median groove.................................................... 8  - Groove separating the lobes of the penis visible............................................................ 9   8(7). Forceps somewhat curved toward median line; without trichomes or minute spines at apex; posterior margin of styliger plate more or less straight; penis rounded and narrow at the base ( Pereira & Da-Silva, 1990: Fig. 2)................  C. cigana  - Forceps curved toward median line, covered with trichomes with 2–3 minute spines at apex; posterior margin of styliger plate short convex; penis square-shaped, not narrow at base..................................  Caenis marataoan  sp. nov.   9(7). Penis with laterally protruding lobes.................................................................... 10  - Lobes of penis very short and not or only slightl y protruding................................................ 13   10(9). Posterior margin of styliger plate straight or rounded....................................................... 11  - Posterior margin of styliger plate subtriangular............................................................ 12   11(10). Fore margin of the styliger sclerite convex; apophyses of styliger sclerite bent inwards ( Malzacher, 2001: Figs 9A–I)..................................................................................................  C. tenella  - Fore margin of the styliger sclerite straight; apophyses of styliger sclerite pointed and straight ( Lima et al. 2015b: Figs 1C, D)........................................................................................  C. gaucha   12(10). Apical margin of penis convex; apophyses of the styliger sclerite bent inwardly, fore margin of the styliger sclerite concave ( Malzacher, 1990: Figs 1A, B)...............................................................  C. pflugfelderi  - Apical margin of penis straight; apophyses of the styliger sclerite pointed and straight, fore margin of the styliger sclerite straight ( Alba-Tercedor & Mosquera, 1999: Figs 1, 4)...............................................  C. chamie   13(9). Lobes of the penis very short and swollen at base; styliger plate usually covering the penis; prosternal triangle narrow and triangular, usually closed toward apex ( Malzacher, 1986: Figs 13A, 16, 18A, B)..........................  C. sigillata  - Lobes of the penis relatively long; styliger plate not covering penis; prosternal triangle broad and usually open toward apex .................................................................................................. 14   14(13). Prosternal triangle very broad and open anteriorly; apex of genital forceps rounded with margins ornamented with small wartlike bumps; basal dilation of the antennal bristle about 1.5 times the length of the pedicel ( Malzacher, 1986: Figs 12E, 13C, 17, 18C)...............................................................................  C. quatipuruica  - Prosternal triangle tapered and open anteriorly; apex of forceps without ornamented margins; basal dilation of the antennal bristle shorter than the length of the pedicel ( Malzacher, 1986: Figs 12C, 13B, 15, 18D–F)....................  C. reissi