Baetidae, Leach, 1815

Kaltenbach, Thomas, Mary, Nathalie & Gattolliat, Jean-Luc, 2021, The Baetidae (Ephemeroptera) of the Comoros and Mayotte, African Invertebrates 62 (2), pp. 427-463 : 427

Key to the Baetidae species of the Comoros and Mayotte (nymphs)

1	Legs stocky with tibiae and tarsi almost fused, claws short and without denticles	Potamocloeon (A.) freitagae
-	Legs elongated with free tibiae and tarsi, claws with denticles	2
2	Claws elongated, with numerous denticles; at least part of the gills formed by two lamellae; abdominal segments VI-IX laterally with strong, apically pointed spines	3
-	Claws not elongated, with less than 15 denticles; all gills formed by a single lamella; abdominal segments VI-IX laterally without spines	4
3	Upper lamella of gills rounded, almost as developed as lower one	Cloeon smaeleni
-	Upper lamella of gills elongated, sometimes as long as lower one, but much narrower	Procloeon (O.) cylindroculum
4	Antennae close to each other with small carina in between; posterior margin of tergite IV with discontinuous row of few reduced, triangular spines (Fig. 12d )	Nigrobaetis richardi sp. nov.
-	Antennae without carina in between; posterior margin of tergite IV with continuous row of triangular spines	5
5	Labial palp segment II with large distomedial protuberance; maxillary palp segment II with distolateral excavation; mandibles without setae between prostheca and mola; fore tibia with patellotibial suture ( Labiobaetis )	6
-	Labial palp segment II without distomedial protuberance; maxillary palp segment II without excavation; at least right mandible with setae between prostheca and mola; fore tibia without patellotibial suture (Protopatellata)	7
6	Seven pairs of gills; hind protoptera well developed	Labiobaetis glaucus
-	Six pairs of gills; hind protoptera absent or vestigial	Labiobaetis vinosus
7	Incisor of both mandibles blade-like, kinetodontium with denticles (Fig. 6b, d ); tibia with an arc of long, fine, simple setae (Fig. 7a ); claw with one row of denticles, without subapical setae (Fig. 7b )	Dabulamanzia mayottensis sp. nov.
-	Incisor and kinetodontium of both mandibles with denticles (Fig. 3b, d ); tibia without arc of fine, simple setae; claw with two rows of denticles and a pair of subapical setae (Fig. 4a, b )	Afroptilum bicorne

Figures

Figure 3. Afroptilum bicorne, nymph morphology: a labrum b right mandible c right prostheca d left mandible e left prostheca f comb-shaped structure below subtriangular process g hypopharynx and superlinguae h maxilla i labium j apex of paraglossa. Scale bar: 0.1 mm.

Figure 4. Afroptilum bicorne, nymph morphology: a foreleg b fore claw c tergum IV d gill IV e paraproct f metanotum (left side), with hind protopteron (mature nymph). Scale bars: 0.1 mm.

Figure 6. Dabulamanzia mayottensis sp. nov., nymph morphology: a labrum b right mandible c right prostheca d right incisor and kinetodontium e left mandible f left prostheca g Left incisor and kinetodontium h hypopharynx and superlinguae i maxilla j labium k apex of paraglossa. Scale bar: 0.1 mm.

Figure 7. Dabulamanzia mayottensis sp. nov., nymph morphology: a foreleg b fore claw c tergum IV d gill IV e paraproct f metanotum (left side), with hind protopteron (mature nymph). Scale bars: 0.1 mm.

Figure 12. Nigrobaetis richardi sp. nov., nymph morphology: a foreleg b seta at dorsal margin of femur c fore claw d tergum IV e gill IV f paraproct g metanotum (left side), with hind protopteron (mature nymph) h gills I, II, III, IV (top to down). Scale bars: 0.1 mm.