Labiobaetis ediai, Kaltenbach & Gattolliat, 2021

Kaltenbach, Thomas & Gattolliat, Jean-Luc, 2021, Labiobaetis Novikova & Kluge in West Africa (Ephemeroptera, Baetidae), with description of a new species, African Invertebrates 62 (1), pp. 355-382 : 360-364

2. Labiobaetis ediai sp. nov. Figures 4b , 5 , 6 , 7

Differential diagnosis.

Nymph. Following combination of characters: A) scape without distolateral process; B) labial palp segment II with rather narrow, thumb-like distomedial protuberance; segment III slightly pentagonal; C) maxillary palp segment II with slight excavation at inner distolateral margin; D) fore femur rather broad, length ca. 3 × maximum width; dorsal margin with 7-9 curved, spine-like setae; femoral patch absent; E) hind protoptera absent; F) six pairs of gills; G) paraproct slightly expanded, with 35-44 marginal spines.

Description.

Nymph (Figs 5 - 7 ). Body length 3.3-4.0 mm. Cerci: slightly shorter than body length. Paracercus: ca. ½ of cerci length. Antenna: approx. 3 × as long as head length.

Colouration (Fig. 5 ). Head, thorax and abdomen dorsally and ventrally brown. Legs light brown, caudalii light brown.

Antenna (Fig. 6f ) with scape and pedicel subcylindrical, without distolateral process at scape.

Labrum (Fig. 7a ). Subrectangular, length 0.6 × maximum width. Distal margin with medial emargination and small process. Dorsally with long, fine, simple setae scattered over surface; submarginal arc of setae composed of ca. 13 long, feathered setae. Ventrally with marginal row of setae composed of lateral and anterolateral long, feathered setae and medial long, bifid, pectinate setae; ventral surface with ca. four short, spine-like setae near lateral and anterolateral margin.

Right mandible (Fig. 7b, c ). Incisor and kinetodontium fused. Incisor with five 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, with minute denticles. Tuft of setae at apex of mola present.

Left mandible (Fig. 7d, 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 almost straight, 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. 7f ). Lingua slightly longer than superlinguae. Lingua longer than broad; medial tuft of stout setae well developed; distal half laterally slightly expanded. Superlinguae distally straight; lateral margins rounded; fine, long, simple setae along distal margin.

Maxilla (Fig. 7g ). 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 three or four simple setae. Maxillary palp longer than length of galea-lacinia; 2-segmented; palp segment II 1.5 × length of segment I; setae on maxillary palp fine, simple, scattered over surface of segments I and II; apex of last segment rounded, with slight excavation at inner distolateral margin.

Labium (Fig. 7h ). Glossa basally broad, narrowing towards apex; shorter than paraglossa; inner margin with four or five spine-like setae, distalmost seta much longer than other setae; apex with two long and one medium, robust, pectinate setae; outer margin with four or five spine-like setae increasing in length distally; ventral surface with fine, simple, scattered setae. Paraglossa sub-rectangular, curved inwards; apex rounded; with three rows of long, robust, distally pectinate setae in apical area and one or two short, simple setae in anteromedial area; dorsally with row of three 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 rather narrow, thumb-like distomedial protuberance; distomedial protuberance 0.5 × width of base of segment III; ventral surface with short, fine, simple setae; dorsally with four spine-like setae near outer margin. Segment III slightly pentagonal; apex slightly pointed; length 1.1 × width; ventrally covered with short, spine-like, simple setae and short, fine, simple setae.

Hind protoptera (Fig. 6g ) absent.

Foreleg (Fig. 6a, b ). Ratio of foreleg segments 1.2:1.0:0.6:0.2. Femur. Length ca. 3 × maximum width. Dorsal margin with 7-9 curved, spine-like setae; length of setae 0.29 × maximum width of femur. Apex rounded, with pair of spine-like setae and some short, stout setae. Stout, lanceolate setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin with row of scarce, fine simple setae. Ventral margin with row of short to medium, curved, spine-like setae, distad of patellotibial suture one longer, curved, spine-like seta, on apex, some longer setae and tuft of fine, simple setae. Anterior surface scattered with short, stout, lanceolate setae. Patellotibial suture present on basal half area. Tarsus. Dorsal margin almost bare. Ventral margin with row of curved, spine-like setae. Claw with one row of nine or ten denticles; distally pointed; with ca. three stripes; subapical setae absent.

Terga (Fig. 6c ). Surface with irregular rows of U-shaped scale bases and scattered fine, simple setae and micropores. Posterior margin of tergum IV with triangular spines, wider than long.

Gills (Fig. 6d ). Present on segments II-VII. Margin with small denticles intercalating fine simple setae. Tracheae extending from main trunk to inner and outer margins. Gill IV as long as length of segments V, VI and half VII combined; gill VII as long as length of segments VIII, IX and half X combined.

Paraproct (Fig. 6e ). Distally slightly expanded, with 35-44 marginal spines. Surface scattered with U-shaped scale bases and micropores. Cercotractor with small, marginal spines.

Etymology.

Dedicated to the collector of the specimens, Dr. Edia Oi Edia ( Université Nangui Abrogoua, Abidjan, Ivory Coast), in recognition of his contribution to the knowledge of aquatic insects from the Ivory Coast.

Biological aspects.

The specimens were collected at altitudes between sea level and 200 m, mostly together with one or several other West African species ( L. elouardi , L. gambiae , L. glaucus , L. latus , L. piscis and L. vinosus ). The characteristics and environmental conditions of some of the sampling sites are described in Edia et al. 2015: table 2 ( Anoblékro = S1, Pont Ehania = Eh2, Pont Soumié = S2): water temperature ca. 25 °C, pH 6.8-7.1 and bottom substrata consisting of 0-25% rocks, 10-35% gravel, 40-45% sand and 20-35% clay/mud.

Distribution.

Ivory Coast (Fig. 4b ).

Type-material.

Holotype. Ivory Coast • nymph; Loc. Pont Ehania, Riv. Ehania ; 05°16'42"N, 02°50'01"W; 14.06.2008; leg. J.-L. Gattolliat and E.O. Edia; on slide; GenBank MH070294 ; GBIFCH00465136 ; MZL. Paratypes. Ivory Coast • 21 nymphs; same data as holotype; 18 in alcohol; GBIFCH00515550 , GBIFCH00515551 , GBIFCH00515623 ; 3 on slides; GenBank MH070295 ; GBIFCH00465137 , GBIFCH00592376 , GBIFCH00592408 ; MZL • 1 nymph; Riv. Soumié, Loc. Anoblekro ; 05°29'44"N, 03°22'15"W; 01.09.2003; leg. E.O. Edia; on slide; GBIFCH00592379 ; MZL • 9 nymphs; Grobiakoko ; 05°51'18"N, 05°31'00"W; 29.10.2006; leg. E.O. Edia; 7 in alcohol; GBIFCH00515541 , GBIFCH00515624 ; 2 on slides; GBIFCH00592401 , GBIFCH00592449 ; MZL • 15 nymphs; Goré; 06°22'28"N, 06°34'27"W; 26.10.2006; leg. E.O. Edia; 14 in alcohol; GBIF CH 00515545 ; 1 on slide; GBIFCH00592738 ; MZL • 2 nymphs; Loc. Réserve Naturelle Banco, Abidjan , station aval; 18.06.2008; leg. J.-L. Gattolliat and E.O. Edia; on slides; GBIFCH00465139 , GBIFCH00465140 ; MZL • 5 nymphs; Riv. Ehania, Pont Ehania ; 05°16'42"N, 02°50'02"W; 12.03.2005; leg. E.O. Edia; 4 in alcohol; GBIFCH00515605 ; 1 on slide; GBIFCH00592457 ; MZL. Other material. Ivory Coast • 11 nymphs; Loc. Pont Soumie ; 05°24'53"N, 03°16'56"W; leg. E.O. Edia; 10 in alcohol; GBIFCH00515612 ; 1 on slide; GBIFCH00592733 ; MZL • 14 nymphs; Riv. Ehania, Loc. Affienou ; 05°24'39"N, 02°55'43"W; 04.08.2004; leg. E.O. Edia; 13 in alcohol; GBIFCH00515613 ; 1 on slide; GBIFCH00592734 ; MZL.

Figures

Figure 4. Distribution of Labiobaetis in West Africa.

Figure 5. Labiobaetis ediai sp. nov., nymph, habitus. Scale bar: 1 mm.

Figure 6. Labiobaetis ediai sp. nov., nymph morphology a foreleg b fore claw c tergum IV d gill IV e paraproct f base of antenna g metanotum (left side), without hind protopteron (mature nymph). Scale bars: 0.1 mm.

Figure 7. Labiobaetis ediai 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 labium. Scale bar: 0.1 mm.