Print
Labiobaetis Novikova & Kluge in Ethiopia (Ephemeroptera, Baetidae), with description of a new species
expand article infoThomas Kaltenbach§, Jean-Luc Gattolliat§
‡ Museum of Zoology, Lausanne, Switzerland
§ University of Lausanne, Lausanne, Switzerland
Open Access

Abstract

Material collected between 2017 and 2019 in Ethiopia in the Awash River catchment substantially increased our knowledge of Labiobaetis Novikova & Kluge in this country. Four species were previously reported based on ecological investigations of Ethiopian rivers: L. glaucus (Agnew, 1961), L. latus (Agnew, 1961), L. vinosus (Barnard, 1932) and L. bellus (Barnard, 1932). We have identified six different species using a combination of morphology and genetic distance (COI, Kimura 2-parameter). Two of them, L. alahmadii Gattolliat & Al Dhafer, 2018 and L. potamoticus Gattolliat & Al Dhafer, 2018 were previously assumed to be endemic to the Arabian Peninsula. The status of L. bellus is discussed and remains unresolved. One species is new to science; it is described and illustrated based on its nymphs. A key to the nymphs of all Ethiopian species is provided. The interspecific K2P distances in Ethiopia are between 17% and 23%, the intraspecific distances are usually between 0% and 1%. The total number of Labiobaetis species worldwide is augmented to 145. The Afrotropical species of Labiobaetis are discussed in comparison to the species of other realms.

Keywords

COI, genetic distance, integrative taxonomy, morphology

Introduction

The family Baetidae has the highest species diversity among mayflies, comprising ca. 1,100 species in 114 genera (updated from Sartori and Brittain 2015; Jacobus et al. 2019; Cruz et al. 2020), which is approximately one third of all mayfly species worldwide. They have a cosmopolitan distribution except in New Zealand (Gattolliat and Nieto 2009). Investigations of the molecular phylogeny of the Order Ephemeroptera revealed the relatively primitive status of the family (Ogden and Whiting 2005; Ogden et al. 2009; Ogden et al. 2019).

Labiobaetis Novikova & Kluge, 1987, is one of the richest genera of mayflies with 144 previously described species (Barber-James et al. 2013; Kaltenbach et al. 2020 and citations therein). The distribution of Labiobaetis is nearly worldwide, except for the Neotropical realm, New Zealand and some remote islands. After a long period of controversy, Labiobaetis is nowadays widely accepted as a valid genus (Gattolliat 2001; Fujitani et al. 2003; Fujitani 2008; McCafferty et al. 2010; Kluge and Novikova 2011, 2014, 2016; Kluge 2012; Webb 2013; Kubendran et al. 2014, 2015; Shi and Tong 2014). The history and concept of the genus Labiobaetis were recently summarized in detail (Shi and Tong 2014; Kaltenbach and Gattolliat 2018). Kluge and Novikova (2016) established a new tribe Labiobaetini including the genera Labiobaetis and Pseudopannota Waltz & McCafferty, 1987, based on a unique combination of imaginal and nymphal characters.

Recently, integrative taxonomy was applied to collections from the highly diverse regions of Southeast Asia and New Guinea, where 65 species were described and named (Kaltenbach and Gattolliat 2018, 2019, 2020; Kaltenbach et al. 2020). This contribution will focus on the Afrotropical country of Ethiopia.

Taxonomic studies of Labiobaetis have a long history in the Afrotropical realm. First, several species were described from South Africa by Barnard (1932), Crass (1947) and Agnew (1961) under the genus Baetis Leach, 1815. Thereafter, Kopelke (1980) named a few species from Central Africa under Baetis, based on adults only. Later, Gillies (1993, 1994) published new species from West and East Africa, still assigned to Baetis. Lugo-Ortiz and McCafferty (1997) made a revision of Labiobaetis in the Afrotropical region including Madagascar and subsequently, Lugo-Ortiz et al. (2000) provided a revision of the widespread species L. glaucus (Agnew, 1961). Gattolliat (2001) described six new species in his comprehensive study of the genus Labiobaetis in Madagascar. Kluge and Novikova (2016) contributed to the fauna of Central Africa and defined the tribe Labiobaetini. Finally, Gattolliat et al. (2018) studied the species from Saudi Arabia, which is bordering the Palaearctic realm, and described two new species. Until now, Labiobaetis encompasses 25 species in the Afrotropical realm, including two species only known from Saudi Arabia (Barber-James et al. 2013; Gattolliat et al. 2018).

The examined material was collected between 2017 and 2019 during ecological studies of the Awash River (Englmaier et al. 2020; Kebede et al. 2020). The collection area encompassed the whole Awash River catchment, including its major affluents (Fig. 1). The Awash River is endorheic; it springs in the Ethiopian Highlands at an altitude of > 3000 m in the Chilimo Forest and flows into the arid Afar Depression, where it finally drains into the saline Lake Abbe at the Ethiopian-Djibouti border, at an altitude of ca. 250 m (Englmaier et al. 2020 and citations therein). The study area including the physical conditions at the sampling sites are described and illustrated in detail in Englmaier et al. (2020: fig. 1, table 1). Apart from the protected Chilimo Forest, the region is subject to extensive anthropogenic impact (intensive agriculture, overgrazing by livestock), resulting in the loss of natural vegetation (Englmaier et al. 2020 and citations therein). The eco-geographical features of Ethiopia, including altitude, geology, hydrology, rainfall, temperature, soil types and land cover, as well as its freshwater ecoregions, are described in Haile and Moog (2016). Ethiopia shares two ecoregions, mainly the Central Eastern Africa ecoregion, but also to a small extent the North Africa and Sahara Desert ecoregion in the northwestern part of the country (Barber-James and Gattolliat 2012).

Table 1.

Sequenced specimens.

Species Locality Specimens catalog # GenBank # (COI) GenSeq Nomenclature
L. alahmadii Ethiopia GBIFCH00763723 MW307223 genseq-4 COI
GBIFCH00763718 MW307225 genseq-4 COI
GBIFCH00763720 MW307222 genseq-4 COI
GBIFCH00763724 MW307224 genseq-4 COI
GBIFCH00763732 MW307227 genseq-4 COI
GBIFCH00763719 MW307226 genseq-4 COI
Saudi Arabia GBIFCH00517527 MH070307 genseq-2 COI
GBIFCH00235747 MH070313 genseq-2 COI
GBIFCH00235757 MH070314 genseq-2 COI
GBIFCH00517526 MH070322 genseq-2 COI
GBIFCH00465155 MH070291 genseq-2 COI
L. excavatus sp. nov. Ethiopia GBIFCH00763725 MW307229 genseq-2 COI
GBIFCH00674636 MW307228 genseq-2 COI
L. glaucus Ethiopia GBIFCH00763728 MW307230 genseq-4 COI
Saudi Arabia GBIFCH00465151 MH070288 genseq-4 COI
GBIFCH00235741 MH070311 genseq-4 COI
GBIFCH00235750 MH105068 genseq-4 COI
GBIFCH00235731 MH070317 genseq-4 COI
GBIFCH00517523 MH070320 genseq-4 COI
South Africa GBIFCH00517537 MH070310 genseq-4 COI
GBIFCH00517539 MH070321 genseq-4 COI
GBIFCH00517538 MH070319 genseq-4 COI
Mayotte GBIFCH00517531 MH105069 genseq-4 COI
GBIFCH00521580 MH070315 genseq-4 COI
GBIFCH00517530 MH070318 genseq-4 COI
L. latus Ethiopia GBIFCH00763729 MW307231 genseq-4 COI
L. potamoticus Ethiopia GBIFCH00763731 MW307235 genseq-4 COI
GBIFCH00763721 MW307233 genseq-4 COI
GBIFCH00763727 MW307234 genseq-4 COI
GBIFCH00674637 MW307232 genseq-4 COI
Saudi Arabia GBIFCH00517520 MH070306 genseq-2 COI
GBIFCH00517521 MH070308 genseq-2 COI
GBIFCH00235735 MH070312 genseq-2 COI
GBIFCH00235732 MH070316 genseq-2 COI
GBIFCH00465152 MH070289 genseq-2 COI
GBIFCH00465154 MH070290 genseq-2 COI
Figure 1. 

Map of Africa with Ethiopia (orange) including the Awash River catchment (green).

So far, the diversity of Labiobaetis in Ethiopia has only become known through an ecological study of the benthic fauna of mountain streams and rivers (Harrison and Hynes 1988). Four species were reported in this study: L. glaucus (Agnew, 1961), L. latus (Agnew, 1961), L. vinosus (Barnard, 1932) and L. bellus (Barnard, 1932). The identity and status of L. bellus is unclear and will be discussed below. Here, we report three additional species from the Awash River catchment, one of which is described and illustrated as a new species, based on nymphs. The total number of Labiobaetis species worldwide is augmented to 145.

Materials and methods

All specimens were collected between 2017 and 2019 by Wolfram Graf (University of Natural Resources and Life Sciences, Austria) and Yonas Terefe (Ambo University, Ethiopia) and preserved in 70–96% ethanol.

The dissection of nymphs was performed in Cellosolve (2-Ethoxyethanol) with subsequent mounting on slides with Euparal liquid, using an Olympus SZX7 stereomicroscope.

The DNA of part of the specimens was extracted using non-destructive methods allowing subsequent morphological analysis (see Vuataz et al. 2011 for details). We amplified a 658 bp fragment of the mitochondrial gene cytochrome oxidase subunit 1 (COI) using the primers LCO 1490 and HCO 2198 (Folmer et al. 1994; see Kaltenbach and Gattolliat 2020 for details). Sequencing was done with Sanger’s method (Sanger et al. 1977). The genetic variability between specimens was estimated using Kimura-2-parameter distances (K2P, Kimura 1980), calculated with MEGA 7 (Kumar et al. 2016, http://www.megasoftware.net).

The GenBank accession numbers are given in Table 1, nomenclature of gene sequences follows Chakrabarty et al. (2013).

Drawings were made using an Olympus BX43 microscope. To facilitate the determination of the new species and the comparison of important structures with other species, we partly used a combination of dorsal and ventral aspects in one drawing (see Kaltenbach et al. 2020: fig. 1).

Photographs of nymphs were taken using a Canon EOS 6D camera and the Visionary Digital Passport imaging system (http://www.duninc.com) and processed with Adobe Photoshop Lightroom (http://www.adobe.com) and Helicon Focus version 5.3 (http://www.heliconsoft.com). Photographs were subsequently enhanced with Adobe Photoshop Elements 13.

The distribution maps were generated with SimpleMappr (https://simplemappr.net, Shorthouse 2010). The GPS coordinates of the sample locations are given in Table 2.

Table 2.

GPS coordinates of locations of examined specimens.

Species Locality GPS coordinates
L. alahmadii Ethiopia: Mille River 11°24'50"N, 40°45'38"E
Ethiopia: Korkada 08°30'03"N, 39°33'07"E
Ethiopia: Lafessa 08°23'16"N, 38°54'31"E
Ethiopia: Worer 09°20'07"N, 40°10'20"E
L. excavatus sp. nov. Ethiopia: Awash 09°04'01"N, 38°08'09"E
L. glaucus Ethiopia: Borkana River 10°39'59"N, 39°55'53"E
Ethiopia: Lafessa 08°23'16"N, 38°54'31"E
Ethiopia: Dubti 11°41'50"N, 41°07'23"E
Ethiopia: Worer 09°20'07"N, 40°10'20"E
Ethiopia: Sulula 08°39'57"N, 38°37'59"E
L. latus Ethipoia: Lafessa 08°23'16"N, 38°54'31"E
L. potamoticus Ethiopia: Dubti 11°41'50"N, 41°07'23"E
Ethiopia: Worer 09°20'07"N, 40°10'20"E
Ethiopia: Wonji 08°28'24"N, 39°12'44"E
Ethiopia: Lafessa 08°23'16"N, 38°54'31"E
Ethiopia: Awash Kunture 08°42'22"N, 38°36'19"E
Ethiopia: Yimre 09°04'59"N, 40°10'03"E
L. vinosus Ethiopia: Lafessa 08°23'16"N, 38°54'31"E
Ethiopia: Korkada 08°30'03"N, 39°33'07"E

The dichotomous key was elaborated with the support of DKey version 1.3.0 (http://drawwing.org/dkey, Tofilski 2018).

The terminology follows Hubbard (1995) and Kluge (2004). The description follows the form of other recent descriptions of Labiobaetis, as for example in Kaltenbach et al. 2020.

Results

Abbreviations

MZL Musée de Zoologie Lausanne (Switzerland).

List of Labiobaetis species from Ethiopia

  1. L. alahmadii Gattolliat & Al Dhafer, 2018
  2. L. excavatus sp. nov.
  3. L. glaucus (Agnew, 1961)
  4. L. latus (Agnew, 1961)
  5. L. potamoticus Gattolliat & Al Dhafer, 2018
  6. L. vinosus (Barnard, 1932)
  7. L. bellus (Barnard, 1932)

(L. bellus: unclear identity and status, no further treatment in this study, see discussion)

Labiobaetis alahmadii Gattolliat & Al Dhafer, 2018

Gattolliat et al. 2018: figs 20–33.

Differential diagnosis

Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with light pattern as Gattolliat et al. 2018: figs 32, 33; B) scape without distolateral process; C) labial palp segment II with thumb-like protuberance; segment III slightly pentagonal; D) maxillary palp segment II with excavation at inner distolateral margin; E) fore femur rather broad, length ca. 3× maximum width; dorsal margin with ca. 18 curved, spine-like setae and many fine, simple setae, and basally some additional spine-like setae near margin; femoral patch reduced; F) fore tibia dorsally with a row of short, spatulate setae (Gattolliat et al. 2018: fig. 26); G) hind protoptera well developed; H) seven pairs of gills; I) paraproct with ca. 16 stout, marginal spines.

Examined material

Ethiopia • 6 nymphs; Lower Mille River; 11°24'50"N, 40°45'38"E; 482 m; leg. W. Graf; 5 in alcohol; GenBank MW307224; GBIFCH00763724, GBIFCH00515555; 1 on slide; GenBank MW307223; GBIFCH00763723 • 1 nymph; Korkada; 08°30'03"N, 39°33'07"E; 09.12.2017; 1260 m; leg. W. Graf; Kk2; in alcohol; GenBank MW307225; GBIFCH00763718 • 1 nymph; Korkada; 08°30'03"N, 39°33'07"E; 1260 m; 09.11.2017; leg. W. Graf; Kk1; in alcohol; GenBank MW307226; GBIFCH00763719 • 1 nymph; Worer; 09°20'07"N, 40°10'20"E; 740 m; 29.01.2018; leg W. Graf; Wr1; in alcohol; GenBank MW307222; GBIFCH00763720 • 1 nymph; Lafessa; 08°23'16"N; 38°54'31"E; 1600 m; 05.11.2017; Lf1; leg. W. Graf; in alcohol; GenBank MW307227; GBIFCH00763732; all material in MZL.

Biological aspects

The specimens were collected at altitudes between 480 m and 1600 m. Further characteristics of sampling sites are given in Englmaier et al. 2020: table 1. In Saudi Arabia, the species occurs in medium-size streams with stony substrates, preferably in relatively fast flowing water or even at the base of small waterfalls (Gattolliat et al. 2018).

Distribution

Ethiopia (Fig. 2a), Saudi Arabia (Gattolliat et al. 2018).

Labiobaetis excavatus sp. nov.

Figures 2a, 3, 4, 5

Differential diagnosis

Nymph. Following combination of characters: A) colouration: abdomen dorsally uniform brown; B) scape with well-developed distolateral process; C) labial palp segment II with broad, thumb-like distomedial protuberance; segment III oblong; D) maxillary palp segment II with strong excavation at inner distolateral margin; E) fore femur rather slender, length 3.6× maximum width; dorsal margin with 18–27 curved, spine-like setae, and a partial row of spine-like setae near margin; femoral patch absent; F) hind protoptera well developed; G) seven pairs of gills; H) paraproct with 15–20 stout marginal spines.

Figure 2. 

Distribution of Labiobaetis in Ethiopia.

Description

Nymph (Figs 35). Body length 7.3–8.5 mm. Cerci: ca. 2/3 of body length. Paracercus: ca. 2/3 of cerci length. Antenna: approx. twice as long as head length.

Colouration (Fig. 3a, b). Head, thorax and abdomen dorsally brown, fore protoptera brown. Head, thorax and abdomen ventrally ecru, frons brown. Legs ecru, femora and tarsi apically brown. Caudalii brown.

Figure 3. 

Labiobaetis excavatus sp. nov., habitus, nymph a dorsal view b ventral view. Scale bars: 1.0 mm.

Antenna (Fig. 4g) with scape and pedicel subcylindrical, with well-developed distolateral process at scape.

Figure 4. 

Labiobaetis excavatus sp. nov., nymph morphology a foreleg b fore claw c tergum IV d gill IV e margin of gill IV f paraproct g antennal scape h metanotum. Scale bars: 0.1 mm.

Labrum (Fig. 5a). Subrectangular, length 0.7× maximum width. Distal margin with medial emargination and small process. Dorsally with medium, fine, simple setae scattered over surface; submarginal arc of setae composed of one plus ca. 17 long, feathered setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid setae; ventral surface with ca. nine short, spine-like setae near lateral and anterolateral margin.

Figure 5. 

Labiobaetis excavatus sp. nov., nymph morphology: a labrum b right mandible c right prostheca d left mandible e left prostheca f hypopharynx and superlinguae g maxilla h apex of maxillary palp (left: dorsal view, right: inner lateral view) i labium j apex of paraglossa. Scale bar: 0.1 mm.

Right mandible (Fig. 5b, c). Incisor and kinetodontium fused. Incisor with four denticles; kinetodontium with three denticles, inner margin of innermost denticle with row of thin setae. Prostheca robust, apically denticulate. Margin between prostheca and mola slightly convex. Tuft of setae at apex of mola present.

Left mandible (Fig. 5d, e). Incisor and kinetodontium fused. Incisor with four denticles; kinetodontium with three denticles. Prostheca robust, apically with small denticles and comb-shaped structure. Margin between prostheca and mola slightly convex, with minute denticles towards subtriangular process. Subtriangular process long and slender, above level of area between prostheca and mola. Denticles of mola apically constricted. Tuft of setae at apex of mola absent.

Both mandibles with lateral margins almost straight. Basal half with fine, simple setae scattered over dorsal surface.

Hypopharynx and superlinguae (Fig. 5f). Lingua longer than superlinguae. Lingua longer than broad; medial tuft of stout setae well developed, short; distal half laterally not expanded. Superlinguae distally rounded; lateral margins rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 5g, h). Galea-lacinia ventrally with two simple, apical setae under canines. Inner dorsal row of setae with three denti-setae, distal denti-seta tooth-like, middle and proximal denti-setae slender, bifid and pectinate. Medially with one pectinate, spine-like seta and six simple setae increasing in length distally. Maxillary palp slightly longer than length of galea-lacinia; 2-segmented; palp segment II 1.4× length of segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment rounded, with strong excavation at inner distolateral margin.

Labium (Fig. 5i, j). Glossa basally broad, narrowing toward apex; shorter than paraglossa; inner margin with ca. seven spine-like setae, distalmost seta much longer than other setae; apex with one long, one medium and one short, robust seta; outer margin with 5–7 spine-like setae increasing in length distally; ventral surface with fine, simple, scattered setae. Paraglossa sub-rectangular, curved inward; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and three or four medium, simple setae in anteromedial area; dorsally with row of five long, spine-like, simple setae near inner margin. Labial palp with segment I 0.7× length of segments II and III combined. Segment I ventrally with short, fine, simple setae. Segment II with broad thumb-like distomedial protuberance; distomedial protuberance 0.9× width of base of segment III; ventral surface with short, fine, simple setae; dorsally with two or three long, spine-like setae near outer margin. Segment III oblong; apex slightly pointed; length 1.2× width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 4h) well developed.

Foreleg (Fig. 4a, b). Ratio of foreleg segments 1.1:1.0:0.4:0.1. Femur. Length 3.6× maximum width. Dorsal margin with 18–27 curved, spine-like setae and partial second row near margin in basal area; length of setae 0.14× maximum width of femur. Apex rounded, with pair of spine-like setae and some short, stout setae. Many stout, lanceolate setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin with row of short, stout setae and fine simple setae, and row of short, stout setae near margin. Ventral margin with row of short, curved, spine-like setae, distally of patellotibial suture one longer, curved, spine-like seta, on apex some longer setae and tuft of fine, simple setae. Anterior surface scattered with stout, lanceolate setae. Patellotibial suture present on basal half area. Tarsus. Dorsal margin with row of short, stout setae and fine, simple setae. Ventral margin with row of curved, spine-like setae. Claw with one row of 10–13 denticles; distally pointed; with ca. five stripes; subapical setae absent.

Terga (Fig. 4c). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae. Posterior margin of tergum IV with triangular spines, ca. as long as wide.

Gills (Fig. 4d, e). Present on segments I–VII. Margin with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Gill I ca. 2/3 length of segment II; gill IV as long as length of segments V and half VI combined; gill VII slightly longer than length of segment VIII.

Paraproct (Fig. 4f). Distally not expanded, with 15–20 stout, marginal spines. Surface scattered with U-shaped scale bases, fine, simple setae and micropores. Cercotractor with small, marginal spines, partly split at apex.

Etymology

Referring to the strongly developed excavation at inner, distolateral margin of maxillary palp segment II.

Biological aspects

The specimens were collected at an altitude of 2400 m in relatively cold water (15.9 °C; see Englmaier et al. 2020: table 1). The sampling site lies in a protected area (S1, National Forest Priority Area), unlike all other sampling sites in this study (Englmaier et al. 2020).

Distribution

Ethiopia (Fig. 2a).

Type-material

Holotype. Ethiopia • nymph; Upper Awash River, Chilimo Forest; 09°04'01"N, 38°08'09"E; 2390 m; 06.11.2017; leg. W. Graf; on slide; GBIFCH00592380; MZL. Paratypes. Ethiopia • 9 nymphs; same data as holotype; 4 on slides; GenBank MW307229, MW307228; GBIFCH00763725, GBIFCH00674636, GBIFCH00592390, GBIFCH00592423; MZL; 5 in alcohol; GBIFCH00515502, GBIFCH00515552; MZL.

Labiobaetis glaucus (Agnew, 1961)

Agnew 1961 (Baetis glaucus)

Lugo-Ortiz and McCafferty 1997: figs 27–38, 39–50 (Labiobaetis masai, L. nadineae; both formal synonyms, Lugo-Ortiz et al. 2000)

Lugo-Ortiz et al. 2000 (Pseudocloeon glaucum)

Gattolliat et al. 2018: figs 34–44, 47

Differential diagnosis

Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with pattern as Gattolliat et al. 2018: fig. 47; B) scape without distolateral process; C) labial palp segment II with broad thumb-like protuberance; D) maxillary palp segment II with excavation at inner distolateral margin; E) fore femur rather broad, length ca. 3× maximum width; dorsal margin with 13–18 curved, spine-like setae and basally some additional setae near margin; femoral patch well developed; F) fore tibia dorsally with a row of scarce, tiny, stout setae (Gattolliat et al. 2018: fig. 40); G) hind protoptera well developed; H) seven pairs of gills; I) paraproct with 5–10 stout, marginal spines.

Examined material

Ethiopia • 6 nymphs; Middle Borkana River; 10°38'09"N, 39°55'53"E; 17.03.2019; 1413 m; leg. W. Graf; 1 on slide; GenBank MW307230; GBIFCH00763728; 5 in alcohol; GBIFCH00515556 • 4 nymphs; Lafessa; 08°23'16"N, 38°54'31"E; 1600 m; 08.11.2017; leg. W. Graf; Lf1; in alcohol; GBIFCH00515557 • 1 nymph; Dubti; 11°41'50"N, 41°07'23"E; 2017; 374 m; leg. W. Graf; S14; in alcohol; GBIFCH00515564 • 1 nymph; Sulula; 08°39'57"N, 38°37'59"E; 1916 m; 07.11.2017; leg. W. Graf; Su1; in alcohol; GBIFCH00515563 • 2 nymphs; Worer; 09°20'6.98"; 40°10'19.50"; 740 m; 29.01.2018; leg. W. Graf; Wr1; 1 on slide; GBIFCH00592437; 1 in alcohol; GBIFCH00515565; all material in MZL.

Biological aspects

The specimens were collected at altitudes from 370 m to 1920 m. Further characteristics of sampling sites are given in Englmaier et al. (2020). Harrison and Hynes (1988) reported the species from 750 m to 1900 m in stony runs and torrents. In Saudi Arabia, the species occurs in small, very shallow streams with moderate current and a substrate mixed of sand, cobbles and rock (Gattolliat et al. 2018).

Distribution

Ethiopia (Fig. 2a; Harrison and Hynes 1988), Saudi Arabia, Comoros (Gattolliat et al. 2018), South Africa, Lesotho, Namibia, Kenya (Lugo-Ortiz et al. 2000), Zimbabwe (Harrison and Hynes 1988) and potentially Iran (Tahmasebi et al. 2020).

Labiobaetis latus (Agnew, 1961)

Agnew 1961 (Baetis latus)

Lugo-Ortiz and McCafferty 1997: figs 1–13 (Labiobaetis aquacidus; formal synonym, Lugo-Ortiz and de Moor 2000)

Differential diagnosis

Nymph. Following combination of characters: A) scape with well-developed distolateral process; C) labial palp segment II with broad thumb-like protuberance; D) maxillary palp segment II with excavation at inner distolateral margin; E) fore femur rather broad, length ca. 3× maximum width; dorsal margin with 13–18 curved, spine-like setae; femoral patch rudimentary or absent; F) hind protoptera well developed; G) seven pairs of gills; H) paraproct with 21–29 stout, marginal spines.

Examined material

Ethiopia • 4 nymphs; Lafessa; 08°23'16"N, 38°54'31"E; 1600 m; 08.11.2017; leg. W. Graf; Lf1; 2 on slides; GenBank MW307231; GBIFCH00763729, GBIFCH00592391; 2 in alcohol; GBIFCH00515558, GBIFCH00515553; all material in MZL.

Biological aspects

The specimens were collected at an altitude of 1600 m. Further characteristics of the sampling site are given in Englmaier et al. (2020). Harrison and Hynes (1988) reported the species at 1900 m in marginal vegetation.

Distribution

Ethiopia (Fig. 2b), South Africa, Kenya (Lugo-Ortiz and McCafferty 1997).

Labiobaetis potamoticus Gattolliat & Al Dhafer, 2018

Gattolliat et al. 2018: figs 1–15, 19

Differential diagnosis

Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with pattern as Gattolliat et al. 2018: fig. 19; B) scape without distolateral process; C) labial palp segment II with small, thumb-like protuberance; segment III slightly pentagonal; D) maxillary palp segment II without excavation at inner distolateral margin; E) fore femur rather broad, length ca. 3× maximum width; dorsal margin with ca. 8 curved, spine-like setae; femoral patch reduced; F) hind protoptera well developed; G) seven pairs of gills; H) paraproct with ca. 36 stout, marginal spines.

Examined material

Ethiopia • 2 nymphs; Wonji; 08°28'24"N, 39°12'44"E; 1550 m; 09.11.2017; leg. W. Graf; Wj1; 1 on slide; GenBank MW307235; GBIFCH00763731; 1 in alcohol; GenBank MW307232; GBIFCH00674637 • 9 nymphs; Dubti; 11°41'50"N, 41°07'23"E; 374 m; leg. W. Graf; S14; 8 in alcohol; GBIFCH00515559; 1 in alcohol; GenBank MW307234; GBIFCH00763727 • 9 nymphs; Worer; 09°20'07"N, 40°10'20"E; 740 m; 29.01.2018; leg. W. Graf; Wr1; 8 in alcohol; GBIFCH00515560; 1 in alcohol; GenBank MW307233; GBIFCH00763721 • 2 nymphs; Yimre; 09°04'59"N, 40°10'03"E; 797 m; leg. W. Graf; 1 on slide; GBIFCH00592436; 1 in alcohol; GBIFCH00515566 • 1 nymph; Awash Kunture; 08°42'22"N, 38°36'19"E; 2003 m; 07.11.2017; leg. W. Graf; Ak1; in alcohol; GBIFCH00515567 • 1 nymph; Lafessa; 08°23'16"N, 38°54'31"E; 1600 m; 09.11.2017; leg. W. Graf; Lf1; in alcohol; GBIFCH00515568; all material in MZL.

Biological aspects

The specimens were collected at altitudes from 370 m to 2000 m. Further characteristics of sampling sites are given in Englmaier et al. (2020). In Saudi Arabia, the species occurs in aquatic vegetation in still reaches of small to medium-sized streams with sandy substrate (Gattolliat et al. 2018).

Distribution

Ethiopia (Fig. 2b), Saudi Arabia (Gattolliat et al. 2018) and potentially Iran (Tahmasebi et al. 2020).

Labiobaetis vinosus (Barnard, 1932)

Barnard 1932

Kopelke 1980 (Pseudocloeon tenuicrinitum; informal synonym, Kluge 2020)

Gillies 1994: figs 16–26 (Baetis spatulatus; formal synonym, Kluge and Novikova 2016)

Lugo-Ortiz and McCafferty 1997: figs 75–86

Kluge and Novikova 2016: figs 113, 122–129, 132, 133 (L. tenuicrinitus; informal synonym, Kluge 2020)

Remark

Judging from the figures and description in Kluge and Novikova (2016), there is no morphological difference between L. vinosus and L. tenuicrinitus. Kluge (2020) also indicates the synonymy of both species. However, no formal synonymy has been established so far. As we have not seen material of L. tenuicrinitus, we are not in a position to formally synonymise both species. Further, the genetic barcode (COI) of both species remains unknown.

Differential diagnosis

Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with pattern as Kluge and Novikova 2016: fig. 113; B) scape without distolateral process; C) labial palp segment II with broad, thumb-like protuberance; segment III conical; D) maxillary palp segment II with excavation at inner distolateral margin; E) fore femur rather broad, length ca. 3× maximum width; dorsal margin with 8–18 curved, spine-like setae and basally a partial second row of setae; F) hind protoptera absent or minute; G) six pairs of gills.

Examined material

Ethiopia • 6 nymphs; Lafessa; 08°23'16"N, 38°54'31"E; 1600 m; 08.11.2017; leg. W. Graf; Lf1; 1 on slide; GBIFCH00592392; 5 in alcohol; GBIFCH00515562, GBIFCH00763730, GBIFCH00829883, GBIFCH00829884, GBIFCH00829885 • 4 nymphs; Korkada; 08°30'03"N, 39°33'07"E; 1260 m; 10.11.2017; leg. W. Graf; Kk1; 3 in alcohol; GBIFCH00515561; 1 on slide; GBIFCH00592388; all material in MZL.

Biological aspects

The specimens were collected at altitudes of 1260 m and 1600 m. Further characteristics of sampling sites are given in Englmaier et al (2020). Harrison and Hynes (1988) reported the species at 2500 m in marginal vegetation.

Distribution

Ethiopia (Fig. 2b), DR Congo (Kopelke 1980), Tanzania (Gillies 1994), Uganda (Kluge and Novikova 2016), South Africa (Lugo-Ortiz and McCafferty 1997).

Key to the Labiobaetis species of Ethiopia (nymphs; excluding L. bellus)

1 Six pairs of gills L. vinosus
Seven pairs of gills 2
2 With distolateral process at scape 3
Without distolateral process at scape 4
3 Maxillary palp with a strongly developed distolateral excavation (Fig. 5g, h), femur dorsally with row of 18 to 27 spine-like setae on margin and a partial row near margin (Fig. 4a), paraproct with 15 to 20 marginal spines (Fig. 4f) L. excavatus sp. nov.
Maxillary palp with distolateral excavation, femur dorsally with a row of 13 to 18 spine-like setae on margin, paraproct with 21 to 29 marginal spines (Lugo-Ortiz and McCafferty 1997: figs 6, 8, 13) L. latus
4 Labial palp segment II with broad thumb-like distomedial protuberance (Gattolliat et al. 2018: figs 24, 39) 5
Labial palp segment II with narrow thumb-like distomedial protuberance (Gattolliat et al. 2018: fig. 8) L. potamoticus
5 Body dorsally with pattern as in Gattolliat et al. 2018: fig. 32, femoral patch poorly developed, tibia dorsally with row of short, spatulate setae (Gattolliat et al. 2018: fig. 26) L. alahmadii
Body dorsally with pattern as in Gattolliat et al. 2018: fig. 47, femoral patch well developed, tibia dorsally with row of scarce, tiny, stout setae (Gattolliat et al. 2018: fig. 40) L. glaucus

Genetics

COI sequences were obtained for five species (Table 1); we failed to get a sequence of L. vinosus, despite several trials. The genetic distances (K2P) among the species are between 17% and 23%, and therefore much higher than 3.5%, which is generally considered as a likely maximal value for intraspecific divergence (Hebert et al. 2003; Ball et al. 2005; Zhou et al. 2010) (Table 3). Very limited genetic distances (between 0% and 4%) were found between specimens of the same species, as in L. potamoticus, L. excavatus sp. nov. and L. alahmadii.

Table 3.

Intraspecific (bold) and interspecific genetic distances of the sequenced specimens (COI; Kimura 2-parameter; %, mean, minimum-maximum).

Species Locations 1 2 3 4 5
1 L. alahmadii Ethiopia, Saudi Arabia 1
0–4
2 L. excavatus sp. nov. Ethiopia 19 1
18–20
3 L. glaucus Ethiopia, Saudi Arabia, South Africa, Mayotte 19 22 1
18–20 21–23 0–2
4 L. latus Ethiopia 19 21 20
19–20 21 20–21
5 L. potamoticus Ethiopia, Saudi Arabia 18 20 19 18 2
17–19 19–20 18–20 17–18 0–4

Discussion

Assignment to Labiobaetis and affinities

For the assignment of the new species to Labiobaetis we refer to Kluge and Novikova (2014). Labiobaetis is characterized by a number of derived characters, some of which are not found in other taxa (Kluge and Novikova 2014): antennal scape sometimes with a distolateral process (Fig. 4g); maxillary palp two segmented with excavation at inner distolateral margin of segment II, excavation may be poorly developed or absent (Fig. 5g); labium with paraglossae widened and glossae diminished; labial palp segment II with distomedial protuberance (Fig. 5i). The concept of Labiobaetis is also based on additional characters, summarized and discussed in Kaltenbach and Gattolliat (2018, 2019). Labiobaetis excavatus sp. nov. is morphologically related to L. latus, sharing the distolateral process at scape, well-developed hind protoptera, seven pairs of gills, and the broad, distomedial protuberance at segment II of the labial palps. The main differences are the stronger distolateral excavation at the maxillary palp of L. excavatus sp. nov. (Fig. 5g, h; Lugo-Ortiz and McCafferty 1997: fig. 6), the number of spine-like setae at dorsal margin of femur (18–27 in L. excavatus sp. nov., plus a partial second row near margin; 13–18 in L. latus) and the presence or absence of setae at the apex of the left mola (present in L. latus, absent in L. excavatus sp. nov.). The strong distolateral excavation of the maxillary palp is very similar to L. punctatus Gattolliat, 2001, from Madagascar, which is also missing the setae at apex of the mola of the left mandible. However, the Malagasy species has no distolateral process at scape and differs by many other characters (Gattolliat 2001: figs 44–54).

Comparison to other realms and species groups

Remarkably, all Afrotropical species of Labiobaetis have a submarginal arc of feathered setae on the dorsal surface of the labrum (Gillies 1994; Lugo-Ortiz et al. 1999; Gattolliat 2001; Gattolliat et al. 2018, this study). In contrast, several additional types of these setae were described from all other regions. The majority of species occur in the Oriental realm and New Guinea. In New Guinea, simple setae were the predominant type, but also feathered setae, clavate setae with pectination, dendritic and lanceolate setae with and without pectination were described (Lugo-Ortiz et al. 1999; Kaltenbach and Gattolliat 2018). In Southeast Asia, simple, feathered and clavate setae are predominant and comparably frequent, but also lanceolate and dendritic setae were described (Müller-Liebenau 1984; Shi and Tong 2014; Kaltenbach and Gattolliat 2019, 2020; Kaltenbach et al. 2020). The type of the dorsal, submarginal setae together with the shape of the distomedial protuberance of labial palp segment II and often combined with other characters are building the base for the morphological species groups defined in Southeast Asia and New Guinea (Kaltenbach and Gattolliat 2018, 2019; Kaltenbach et al. 2020). These morphological groups within Labiobaetis are primarily a working tool but some may be natural groups and could also serve as a basis for future studies on the generic delimitation and phylogeny of this genus. Afrotropical Labiobaetis are not only sharing the feathered type of dorsal, submarginal setae on the labrum, but also have mostly a broad thumb-like distomedial protuberance of labial palps segment II. A lot of the variation between the species is coming from different combinations of characters like seven or six pairs of gills, presence or absence of hind protoptera and presence or absence of a distolateral process at scape. The reduction and secondary loss of these characters seems to be a general tendency in Labiobaetis (Kluge and Novikova 2014; Kaltenbach and Gattolliat 2018, 2019) and they are, therefore, less reliable characters to define morphological groups. There are a few species with a narrow distolateral protuberance at labial palps segment II (L. piscis Lugo-Ortiz & McCafferty, 1997; L. longicercus Gattolliat, 2001; L. potamoticus), which are at the same time sharing seven pairs of gills, the absence of a distolateral process at scape and, more important, the absence of setae at the apex of the mola of the left mandible. These species are probably forming a morphological group amongst the other Afrotropical species. However, this is out of the scope of this paper and further investigations on other Afrotropical regions are necessary to discuss possible relationships of Labiobaetis species in this realm. Based on the present knowledge, all Afrotropical species of Labiobaetis seem to be morphologically closely related to the Southeast Asian operosus and difficilis groups (Kaltenbach and Gattolliat 2019). Both groups are very close to each other; the only difference is the presence (operosus group) or absence (difficilis group) of hind protoptera, which is a rather unreliable group character (see above).

The distribution of the Labiobaetis species seems to be also different in the Afrotropical realm compared to Southeast Asia and New Guinea. Apart from Madagascar, where all Labiobaetis species are endemic to the island (Gattolliat 2001), some Afrotropical species have a wide or even very wide distribution, e.g. L. potamoticus (Saudi Arabia, Ethiopia, potentially Iran), L. latus (Ethiopia, Kenya, South Africa), L. vinosus (Ethiopia, DR Congo, Tanzania, Uganda, South Africa) and especially L. glaucus (Ethiopia, Iran (?), Saudi Arabia, Comoros, Kenya, Namibia, Zimbabwe, South Africa). On the contrary, most species in Southeast Asia and New Guinea are restricted to smaller regions or are endemic to one island. An exception is L. moriharai Müller-Liebenau, 1984, known from Malaysia, Vietnam and Borneo (Kaltenbach and Gattolliat 2018, 2019, 2020; Kaltenbach et al. 2020). The reason for this difference is probably due to the high number of islands in Southeast Asia, especially in Indonesia and the Philippines, and the extreme landscape structure in New Guinea, facilitating allopatric speciation and endemicity (Toussaint et al. 2013, 2014; Kaltenbach and Gattolliat 2018, 2019; Kaltenbach et al. 2020). The huge African continent is in comparison geographically less structured, which is generally facilitating larger distribution areas of species.

Labiobaetis bellus

Since its description as a new species by Barnard (1932), L. bellus was regularly reported from South Africa and other countries, mainly in ecological studies of rivers (e.g. Crass 1947; Harrison 1950; Kimmins 1960; Oliff and King 1964; Chutter 1970, 1971; Harrison and Hynes 1988; Samways et al. 2011). However, apart from a rather sketchy drawing of the labial palp (Barnard 1932: fig. 13k), there are no further drawings of the mouthparts in Barnard (1932) and his description of the nymph is not precise enough to differentiate it unambiguously from other species. Additionally, he mentioned that L. bellus and Cheleocloeon excisum (Barnard, 1932) “...approach each other very closely in the character of the mouth-parts of the nymphs.” (Barnard 1932: 204). Later, already Kimmins (1960) was not sure about his determination of “Baetis ? bellus” from Uganda and proposed to solve the determination issues by studying nymphs rather than adults. Lugo-Ortiz and McCafferty (1997) did not mention L. bellus at all in their comprehensive study on Afrotropical Labiobaetis, contrary to L. vinosus, which Barnard (1932) described in the same paper. We may assume that these authors could not clarify the identity and the status of L. bellus. It remains unclear what Harrison and Hynes (1988) and other authors include in their concept of “L. bellus”. Moreover, most of the reports of the species were anterior to the revision of the genus in the Afrotropics (Lugo-Ortiz and McCafferty 1997) and must be therefore considered as uncertain. Therefore, we refrain from further treatment of L. bellus before its species concept is clarified based on material from South Africa.

In comparison to L. excavatus sp. nov. with its broad distomedial protuberance at labial palp segment II similar to L. latus, the drawing of L. bellus in Barnard 1932: fig. 13k shows a more slender protuberance, more similar to L. piscis and L. potamoticus; Labiobaetis piscis and L. potamoticus may be easily confused with each other and L. potamoticus is abundant in the Awash River. In addition, L. bellus was reported from several places and different altitudes in the Awash River, contrary to L. excavatus sp. nov., which was found in the natural Chilimo Forest (2400 m) only, despite intensive sampling efforts along the Awash River. Further, L. excavatus sp. nov. is very similar to L. latus, which is reported additionally to L. bellus by Harrison and Hynes (1988). Therefore, we may assume that “L. bellus” sensu Harrison and Hynes (1988) has obvious differences to L. latus and thus to L. excavatus sp. nov. as well. As a conclusion, we assume that L. excavatus sp. nov. cannot be conspecific with L. bellus, the latter species being in the need of a taxonomic revision.

Genetic distance

The interspecific genetic distances found in Ethiopia (17–23%, Table 3) are in line with the ones between Labiobaetis species in other regions like New Guinea (average 22%; Kaltenbach and Gattolliat 2018), Indonesia (11–24%; Kaltenbach and Gattolliat 2019), Borneo (19–25%; Kaltenbach and Gattolliat 2020) and the Philippines (15–27%; Kaltenbach et al. 2020). Ball et al. (2005) reported a mean interspecific, congeneric distance of 18% for mayflies from the United States and Canada.

Two species, L. alahmadii and L. potamoticus, have intraspecific distances of up to 4%. In L. alahmadii, two specimens from Ethiopia have of genetic distance of 3%–4% to all other sequenced specimens from Ethiopia and Saudi Arabia. All other specimens have distances of 0%–1% between themselves, as well in Ethiopia as between Ethiopia and Saudi Arabia. Intraspecific distances of 4%–6% were also reported in some cases for Labiobaetis species in New Guinea, Indonesia, Borneo and the Philippines (Kaltenbach and Gattolliat 2018, 2019, 2020; Kaltenbach et al. 2020), as well as in aquatic beetles in the Philippines (Komarek and Freitag 2020). Ball et al. (2005) also reported a case with 6% intraspecific distance in a mayfly in North America and intraspecific K2P distances of more than 3.5% are not uncommon within Plecoptera as well (Gill et al. 2015; Gattolliat et al. 2016). In L. potamoticus, the specimens from Ethiopia have distances of 0–1% between each other, and the higher distances of 3–4% are only between specimens from Ethiopia and Saudi Arabia, which can be explained by the greater geographic distance.

The COI sequence of L. latus from Ethiopia has a distance of 22% to another specimen from South Africa, reported in Gattolliat et al. (2018: table 1; GenBank MH070297, GBIF00465142), without any morphological difference between the two specimens. In the meantime, a second specimen from the same location in South Africa was sequenced and has the same barcode as the first specimen. Further, several COI barcodes with a distance of just 5–6% to the one from Ethiopia were obtained from specimens in South Africa as well, which may be explained by the geographic distance between Ethiopia and South Africa. There seem to be two different widespread mitochondrial lineages corresponding to the morphological concept of L. latus. This problem cannot be solved without additional investigations, including in particular nuclear genes, as it was recently done in the similar case of Baetis harrisoni Barnard, 1932 (Pereira da Conceicoa et al. 2012). Different mitochondrial lineages with the same morphology were already reported several times in Labiobaetis (Kaltenbach and Gattolliat 2018, 2019; Kaltenbach et al. 2020).

The number of sampled localities and different habitats in Ethiopia is still limited and there are regions without any collection activities so far (Fig. 2). However, the distribution of Labiobaetis species in Africa is often much more widespread than in other regions and suitable habitats are limited in this semiarid area. Therefore, we may expect a few, but not many more species to be discovered in Ethiopia with further collections.

Acknowledgements

We sincerely thank Wolfram Graf (University of Natural Resources and Life Sciences, Austria) and Yonas Terefe (Ambo University, Ethiopia) for the collection of this precious material and for making it available to the Museum of Zoology in Lausanne (MZL). Fieldwork was conducted under the auspices of the LARIMA Project (Project Number 106) funded by the Austrian Partnership Programme in Higher Education and Research for Development (APPEAR) of the Austrian Development Cooperation (ADC) and the Austrian Agency for International Cooperation in Education and Research (OeAD). Field research was supported by the National Fisheries and Aquatic Life Research Center (NFALRC) and the Ethiopian Institute of Agricultural Research (EIAR) (Permit Numbers 1.9/0323/2017, 1.9/3196/ 2018, 1.9/0336/2019). We are also thankful to Michel Sartori (MZL) for his constant interest and support for our projects and to Marion Podolak (MZL) and Maud Liégeois (University of Lausanne, UNIL) for their support with lab work and preparation of the COI barcodes. Lastly, the authors are grateful to the reviewers for their valuable recommendations and comments on the manuscript.

References

  • Agnew JD (1961) New Baetidae (Ephem.) from South Africa. Novos Taxa Entomologicos 26: 1–9.
  • Ball SL, Hebert PDN, Burian SK, Webb JM (2005) Biological identifications of mayflies (Ephemeroptera) using DNA barcodes. Journal of the North American Benthological Society 24(3): 508–524. https://doi.org/10.1899/04-142.1
  • Barber-James HM, Gattolliat J (2012) How well are Afrotropical mayflies known? Status of current knowledge, practical applications, and future directions. Inland Waters 2(1): 1–9. https://doi.org/10.5268/IW-2.1.447
  • Chakrabarty P, Warren M, Page LM, Baldwin CC (2013) GenSeq: An updated nomenclature and ranking for genetic sequences from type and non-type sources. ZooKeys 346: 29–41. https://doi.org/10.3897/zookeys.346.5753
  • Chutter FM (1970) Hydrobiological studies in the catchment of Vaal Dam, South Africa. Part 1. River zonation and the benthic fauna. Internationale Revue der Gesamten Hydrobiologie 55(3): 445–494. https://doi.org/10.1002/iroh.19700550315
  • Chutter FM (1971) Hydrobiological studies in the catchment of Vaal Dam, South Africa. Part 2. The effects of stream contamination on the fauna of stones-in-current and marginal vegetation biotopes. Internationale Revue der Gesamten Hydrobiologie 56(2): 227–240. https://doi.org/10.1002/iroh.19710560205
  • Crass RS (1947) The may-flies (Ephemeroptera) of Natal and the Eastern Cape. Annals of the Natal Museum 11: 37–110.
  • Cruz PV, Nieto C, Gattolliat J-L, Salles FF, Hamada N (2020) A cladistic insight into higher level classification of Baetidae (Insecta: Ephemeroptera). Systematic Entomology 2020: 1–12. https://doi.org/10.1111/syen.12446
  • Englmaier GK, Hayes DS, Meulenbroek P, Terefe Y, Lakew A, Tesfaye G, Waidbacher H, Malicky H, Wubie A, Leitner P, Graf W (2020) Longitudinal river zonation in the tropics: Examples of fish and caddisflies from the endorheic Awash River, Ethiopia. Hydrobiologia 847(19): 4063–4090. https://doi.org/10.1007/s10750-020-04400-0
  • Folmer O, Black M, Hoeh W, Lutz R, Vrijenhoek R (1994) DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from divers metazoan invertebrates. Molecular Marine Biology and Biotechnology 3: 294–299. http://www.mbari.org/staff/vrijen/PDFS/Folmer_94MMBB.pdf
  • Fujitani T (2008) The family Baetidae from Japan. In: Hauer FR, Stanford JA, Newell RL (Eds) International Advances in the Ecology, Zoogeography and Systematics of Mayflies and Stoneflies. University of California Press, Berkeley, 205–218. https://doi.org/10.1525/california/9780520098688.003.0015
  • Fujitani T, Hirowatari T, Tanida K (2003) Genera and species of Baetidae in Japan: Nigrobaetis, Alainites, Labiobaetis, and Tenuibaetis n. stat. (Ephemeroptera). Limnology 4(3): 121–129. https://doi.org/10.1007/s10201-003-0105-2
  • Gattolliat J-L (2001) Six new species of Labiobaetis Novikova & Kluge (Ephemeroptera: Baetidae) from Madagascar with comments on the validity of the genus. Annales de Limnologie 37(2): 97–123. https://doi.org/10.1051/limn/2001013
  • Gattolliat J-L, Vinçon G, Wyler S, Pawlowski J, Sartori M (2016) Toward a comprehensive COI DNA barcode library for Swiss Stoneflies (Insecta: Plecoptera) with special emphasis on the genus Leuctra. Zoosymposia 11: 135–155. https://doi.org/10.11646/zoosymposia.11.1.15
  • Gattolliat J-L, Kondratieff BC, Kaltenbach T, Al Dhafer HM (2018) Labiobaetis from the Kingdom of Saudi Arabia (Insecta: Ephemeroptera: Baetidae). ZooKeys 774: 77–104. https://doi.org/10.3897/zookeys.774.25273
  • Gill BA, Sandberg JB, Kondratieff BC (2015) Evaluation of the morphological species concepts of 16 western Nearctic Isoperla species (Plecoptera: Perlodidae) and their respective species groups using DNA barcoding. Illiesia 11: 130–146. http://illiesia.speciesfile.org/papers/Illiesia11-11.pdf
  • Haile AL, Moog O (2016) LARIMA. Deliverable 1.3: Top-down operative stream classification system (topology) for Ethiopian highlands. Appear-Austrian Partnership Programme in High Education & Research for Development, 1–61.
  • Harrison AC (1950) Cape may-flies. Part VI. The family Baetidae. Journal of the Cape Piscadorial Society Cape Town, South Africa 14: 51–55.
  • Harrison AD, Hynes HBN (1988) Benthic fauna of Ethiopian mountain streams and rivers. Archiv für Hydrobiologie (Supplement 81): 1–36.
  • Hebert PDN, Cywinska A, Ball SL, DeWaard JR (2003) Biological identifications through DNA barcodes. Proceedings. Biological Sciences 270(1512): 313–321. https://doi.org/10.1098/rspb.2002.2218
  • Hubbard MD (1995) Towards a standard methodology for the description of mayflies (Ephemeroptera). In: Corkum LD, Ciborowski JJH (Eds) Current directions in research on Ephemeroptera. Canadian Scholar’s Press, Toronto, 361–369.
  • Kaltenbach T, Gattolliat J-L (2018) The incredible diversity of Labiobaetis Novikova & Kluge in New Guinea revealed by integrative taxonomy (Ephemeroptera, Baetidae). ZooKeys 804: 1–136. https://doi.org/10.3897/zookeys.804.28988
  • Kaltenbach T, Garces JM, Gattolliat J-L (2020) The success story of Labiobaetis Novikova & Kluge in the Philippines (Ephemeroptera, Baetidae), with description of 18 new species. ZooKeys 1002: 1–114. https://doi.org/10.3897/zookeys.1002.58017
  • Kebede G, Mushi D, Linke RB, Dereje O, Lakew A, Hayes DS, Farnleitner AH, Graf W (2020) Macroinvertebrate indices versus microbial fecal pollution characteristics for water quality monitoring reveals contrasting results for an Ethiopian river. Ecological Indicators 108: 1–10. https://doi.org/10.1016/j.ecolind.2019.105733
  • Kimmins DE (1960) Notes on East African Ephemeroptera with descriptions of new species. Bulletin of the British Museum (Natural History). Entomology 9: 337–355. https://doi.org/10.5962/bhl.part.27555
  • Kimura M (1980) A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences. Journal of Molecular Evolution 16(2): 111–120. https://doi.org/10.1007/BF01731581
  • Kluge NJ, Novikova EA (2011) Systematics of the mayfly taxon Acentrella (Ephemeroptera, Baetidae), with description of new Asian and African species. Russian Entomological Journal 20(1): 1–56. https://doi.org/10.15298/rusentj.20.1.01
  • Kluge NJ, Novikova EA (2014) Systematics of Indobaetis Müller-Liebenau & Morihara 1982, and related implications for some other Baetidae genera (Ephemeroptera). Zootaxa 3835(2): 209–236. https://doi.org/10.11646/zootaxa.3835.2.3
  • Kluge NJ, Novikova EA (2016) New tribe Labiobaetini tribus n., redefinition of Pseudopannota Waltz & McCafferty 1987 and descriptions of new and little known species from Zambia and Uganda. Zootaxa 4169(1): 1–43. https://doi.org/10.11646/zootaxa.4169.1.1
  • Komarek A, Freitag H (2020) Taxonomic revision of Agraphydrus Régimbart, 1903. IV. Philippines. (Coleoptera: Hydrophilidae: Acidocerinae). Koleopterologische Rundschau 90: 201–242.
  • Kopelke J-P (1980) Ephemeroptera aus der Emergenz des zentralafrikanischen Bergbaches Kalengo (Zaire) Teil I: Baetidae. Entomologische Abhandlungen 43: 99–129.
  • Kubendran T, Rathinakumar T, Balasubramanian C, Selvakumar C, Sivaramakrishnan KG (2014) A new species of Labiobaetis Novikova & Kluge, 1987 (Ephemeroptera: Baetidae) from the southern Western Ghats in India, with comments on the taxonomic status of Labiobaetis. Journal of Insect Science 14(86): 1–10. https://doi.org/10.1673/031.014.86
  • Kubendran T, Balasubramanian C, Selvakumar C, Gattolliat J-L, Sivaramakrishnan KG (2015) Contribution to the knowledge of Tenuibaetis Kang & Yang 1994, Nigrobaetis Novikova & Kluge 1987 and Labiobaetis Novikova & Kluge (Ephemeroptera: Baetidae) from the Western Ghats (India). Zootaxa 3957: 188–200. https://doi.org/10.11646/zootaxa.3957.2.3
  • Kumar S, Stecher G, Tamura K (2016) MEGA 7: Molecular evolutionary genetics analysis version 7.0 for bigger data sets. Molecular Biology and Evolution 33(7): 1870–1874. https://doi.org/10.1093/molbev/msw054
  • Lugo-Ortiz CR, de Moor FC (2000) Pseudocloeon aquacidum: a new subjective synonym of P. latum (Ephemeroptera: Baetidae). Entomological News 111: 380–381.
  • Lugo-Ortiz CR, McCafferty WP (1997) Labiobaetis Novikova & Kluge (Ephemeroptera: Baetidae) from the Afrotropical region. African Entomology 5: 241–260.
  • Lugo-Ortiz CR, McCafferty WP, Waltz RD (1999) Definition and reorganization of the genus Pseudocloeon (Ephemeroptera: Baetidae) with new species descriptions and combinations. Transactions of the American Entomological Society 125: 1–37.
  • Lugo-Ortiz CR, de Moor FC, Barber-James HM (2000) A taxonomic and ecological review of Pseudocloeon glaucum (Agnew) (Ephemeroptera: Baetidae). African Entomology 8: 281–288.
  • McCafferty WP, Lenat DR, Jacobus LM, Meyer MD (2010) The mayflies (Ephemeroptera) of the southeastern United States. Transactions of the American Entomological Society 136(3 & 4): 221–233. https://doi.org/10.3157/061.136.0303
  • Müller-Liebenau I (1984) New genera and species of the family Baetidae from West-Malaysia (River Gombak) (Insecta: Ephemeroptera). Spixiana 7: 253–284.
  • Ogden TH, Gattolliat J-L, Sartori M, Staniczek AH, Soldan T, Whiting MF (2009) Towards a new paradigm in mayfly phylogeny (Ephemeroptera): Combined analysis of morphological and molecular data. Systematic Entomology 34(4): 616–634. https://doi.org/10.1111/j.1365-3113.2009.00488.x
  • Ogden TH, Breinholt JW, Bybee SM, Miller DB, Sartori M, Shiozawa D, Whiting MF (2019) Mayfly phylogenomics: Initial evaluation of anchored hybrid enrichement data for the order Ephemeroptera. Zoosymposia 16: 167–181.
  • Oliff WD, King JL (1964) Hydrobiological studies of the Tugela River System. Part IV. The Mooi River. Hydrobiologia 24(3-4): 567–583. https://doi.org/10.1007/BF00142003
  • Pereira da Conceicoa LL, Price BW, Barber-James HM, Barker NP, de Moor FC, Villet MH (2012) Cryptic variation in an ecological indicator organism: mitochondrial and nuclear DNA sequence data confirm distinct lineages of Baetis harrisoni Barnard (Ephemeroptera: Baetidae) in southern Africa. BMC Evolutionary Biology 12(1): 1–14. https://doi.org/10.1186/1471-2148-12-26
  • Samways MJ, Sharratt NJ, Simaika JP (2011) Effect of alien riparian vegetation and its removal on a highly endemic river macroinvertebrate community. Biological Invasions 13(6): 1305–1324. https://doi.org/10.1007/s10530-010-9891-8
  • Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain-terminating inhibitors. Proceedings of the National Academy of Sciences of the United States of America 74(12): 5463–5467. https://doi.org/10.1073/pnas.74.12.5463
  • Shorthouse DP (2010) SimpleMappr, an online tool to produce publication-quality point maps. Retrieved from https://www.simplemappr.net [Accessed July 03, 2020]
  • Tahmasebi J, Siahkalroudi SY, Kheradpir N (2020) A scientific report on Ephemeroptera of Jajrood river, Northern Iran. Journal of Wildlife and Biodiversity 4: 1–8.
  • Toussaint EA, Sagata K, Surbakti S, Hendrich L, Balke M (2013) Australasian sky islands act as a diversity pump facilitating peripheral speciation and complex reversal from narrow endemic to widespread ecological supertramp. Ecology and Evolution 3(4): 1031–1049. https://doi.org/10.1002/ece3.517
  • Toussaint EA, Hall R, Monaghan MT, Sagata K, Ibalim S, Shaverdo HV, Vogler AP, Pons J, Balke M (2014) The towering orogeny of New Guinea as a trigger for arthropod megadiversity. Nature Communications 5(1): 4001–4010. https://doi.org/10.1038/ncomms5001
  • Vuataz L, Sartori M, Wagner A, Monaghan MT (2011) Toward a DNA taxonomy of Alpine Rhithrogena (Ephemeroptera: Heptagenidae) using a mixed Yule-Coalescent Analysis of mitochondrial and nuclear DNA. PLoS ONE 6(5): 1–11. https://doi.org/10.1371/journal.pone.0019728
  • Zhou X, Jacobus LM, DeWalt RE, Adamowicz SJ, Hebert PDN (2010) Ephemeroptera, Plecoptera, and Trichoptera fauna of Churchill (Manitoba, Canada): Insights into biodiversity patterns from DNA barcoding. Journal of the North American Benthological Society 29(3): 814–837. https://doi.org/10.1899/09-121.1