Caenis, Stephens, 1836

Nascimento, Stênio R. S., Rodrigues, Jackson A. O., Ale-Rocha, Rosaly & Lima, Lucas R. C., 2022, New species and records of Caenidae Newman, 1853 (Insecta: Ephemeroptera) from Northeastern Brazil, Zootaxa 5133 (1), pp. 110-122 : 119-120

publication ID

https://doi.org/10.11646/zootaxa.5133.1.5

publication LSID

lsid:zoobank.org:pub:54E7DF54-B8F1-48C5-A488-F60601134790

DOI

https://doi.org/10.5281/zenodo.6522847

persistent identifier

https://treatment.plazi.org/id/432587DC-FFC6-FFCA-FF06-B388FA50B425

treatment provided by

Plazi

scientific name

Caenis
status

 

Male imagos of Caenis from Brazil (adapted from Domínguez et al. 2006)

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 View FIGURE 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 View FIGURE 3 , 5 View FIGURE , 6A–F View FIGURE 6 )................... 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 View FIGURE , 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 View FIGURE , 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 View FIGURE 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 View FIGURE 1 )........................................................................................ 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 View FIGURE 1 )............................................................... 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 View FIGURE 1 , 4 View FIGURE 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

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Ephemeroptera

Family

Caenidae