Research Article |
Corresponding author: Thomas Kaltenbach ( thomas.kaltenbach@bluewin.ch ) Academic editor: John Midgley
© 2021 Thomas Kaltenbach, Jean-Luc Gattolliat.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kaltenbach T, Gattolliat J-L (2021) Labiobaetis Novikova & Kluge in Ethiopia (Ephemeroptera, Baetidae), with description of a new species. African Invertebrates 62(1): 231-255. https://doi.org/10.3897/afrinvertebr.62.62029
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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.
COI, genetic distance, integrative taxonomy, morphology
The family Baetidae has the highest species diversity among mayflies, comprising ca. 1,100 species in 114 genera (updated from
Labiobaetis Novikova & Kluge, 1987, is one of the richest genera of mayflies with 144 previously described species (
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 (
Taxonomic studies of Labiobaetis have a long history in the Afrotropical realm. First, several species were described from South Africa by
The examined material was collected between 2017 and 2019 during ecological studies of the Awash River (
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 |
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 (
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
The GenBank accession numbers are given in Table
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
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,
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,
The terminology follows
(L. bellus: unclear identity and status, no further treatment in this study, see discussion)
Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with light pattern as
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
The specimens were collected at altitudes between 480 m and 1600 m. Further characteristics of sampling sites are given in
Ethiopia (Fig.
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.
Nymph
(Figs
Colouration (Fig.
Antenna (Fig.
Labrum (Fig.
Right mandible (Fig.
Left mandible (Fig.
Both mandibles with lateral margins almost straight. Basal half with fine, simple setae scattered over dorsal surface.
Hypopharynx and superlinguae (Fig.
Maxilla (Fig.
Labium (Fig.
Hind protoptera (Fig.
Foreleg (Fig.
Terga (Fig.
Gills (Fig.
Paraproct (Fig.
Referring to the strongly developed excavation at inner, distolateral margin of maxillary palp segment II.
The specimens were collected at an altitude of 2400 m in relatively cold water (15.9 °C; see
Ethiopia (Fig.
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;
Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with pattern as
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
The specimens were collected at altitudes from 370 m to 1920 m. Further characteristics of sampling sites are given in
Ethiopia (Fig.
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.
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
The specimens were collected at an altitude of 1600 m. Further characteristics of the sampling site are given in
Ethiopia (Fig.
Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with pattern as
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
The specimens were collected at altitudes from 370 m to 2000 m. Further characteristics of sampling sites are given in
Ethiopia (Fig.
Judging from the figures and description in
Nymph. Following combination of characters: A) colouration: abdomen dorsally brown, with pattern as
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
The specimens were collected at altitudes of 1260 m and 1600 m. Further characteristics of sampling sites are given in
Ethiopia (Fig.
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. |
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 ( |
L. latus |
4 | Labial palp segment II with broad thumb-like distomedial protuberance ( |
5 |
– | Labial palp segment II with narrow thumb-like distomedial protuberance ( |
L. potamoticus |
5 | Body dorsally with pattern as in |
L. alahmadii |
– | Body dorsally with pattern as in |
L. glaucus |
COI sequences were obtained for five species (Table
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 |
For the assignment of the new species to Labiobaetis we refer to
Remarkably, all Afrotropical species of Labiobaetis have a submarginal arc of feathered setae on the dorsal surface of the labrum (
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 (
Since its description as a new species by
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
The interspecific genetic distances found in Ethiopia (17–23%, Table
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 (
The COI sequence of L. latus from Ethiopia has a distance of 22% to another specimen from South Africa, reported in
The number of sampled localities and different habitats in Ethiopia is still limited and there are regions without any collection activities so far (Fig.
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 (