Centroptilum alamiae Kaltenbach, Vuataz & Gattolliat, 2022

Kaltenbach, Thomas, Vuataz, Laurent, Samraoui, Boudjema, El Yaagoubi, Sara, El Alami, Majida & Gattolliat, Jean-Luc, 2022, Two new species of Centroptilum Eaton, 1869 from North Africa (Ephemeroptera, Baetidae), ZooKeys 1131, pp. 71-97 : 71

Centroptilum alamiae Kaltenbach, Vuataz & Gattolliat sp. nov.

Figs 4b, e , 5b , 6 , 7 , 8 , 9

Differential diagnosis to other species of Centroptilum .

Larva. Following combination of characters: A) labrum with anterior margin slightly concave; ratio width vs. length ca. 1.5 × (Fig. 7a ); B) maxillary palp ca. 1.7 × as long as galea-lacinia, segment III apically rounded; segment III ca. 1.6 × as long as segment II (Fig. 7g ); C) inner distal margin of labial palp segment III slightly concave (Fig. 7k ); D) dorsal margin of fore femur with occasional short, spine-like setae; row of stout, pointed setae near margin (Fig. 8a ); E) tarsus approx. as long as tibia (Fig. 8a ); F) claw with two rows of denticles, each row with ca. 20 small to minute denticles (Fig. 8b ); G) paraproct with 30-45 pointed spines, sometimes with split tips, few additional, submarginal spines (Fig. 8j ).

Description.

Larva (Figs 4b, e , 5b , 7 - 9 ). Body length 5.6-7.0 mm. Caudalii broken. Antennae reaching apex of fore protoptera.

Colouration (Fig. 9a-c ). Head, thorax and abdomen dorsally brown, with dark grey-brown pattern as in Fig. 9a . Head, thorax and abdomen ventrally light brown, with dark grey-brown lateral marks on thorax (Fig. 9c ). Legs light brown, femur distomedially slightly darker, tarsus basally and distally slightly darker, claw basally darker. Caudalii light brown, darker annulated.

Labrum (Fig. 7a ). Rectangular, width ca. 1.5 × maximum length. Distal margin with broad, angulated, medial emargination. Anterior margin slightly concave. Dorsal surface scattered with long, medium and short, simple setae; setae not arranged in a submarginal arc. Ventrally with marginal row of setae composed of anterolateral long, simple, pointed setae and medial long, apically blunt, pectinate setae; ventral surface with ca. nine short, stout setae near lateral and anterolateral margin.

Right mandible (Fig. 7b, c ). Incisor and kinetodontium separated. Incisor with three denticles; kinetodontium with two denticles. Prostheca stick-like, distally with three denticles. Margin between prostheca and mola almost straight, with two tufts of long setae. Tuft of setae at apex of mola present.

Left mandible (Fig. 7d, e ). Incisor and kinetodontium separated. Incisor with four denticles; kinetodontium with three denticles. Prostheca stick-like, distolaterally denticulate. Margin between prostheca and mola straight, with large brush-like tuft of long setae. Subtriangular process short, on level of area between prostheca and mola. Tuft of setae at apex of mola absent.

Hypopharynx and superlinguae (Fig. 7f ). Lingua as long as superlinguae. Lingua longer than broad; distal half laterally not expanded; distal margin with short, fine setae, tuft of stout setae short. Superlinguae distally rounded; lateral margins rounded; fine, short to long, simple setae along distal margin.

Maxilla (Fig. 7g ). Galea-lacinia ventrally with four or five simple, apical setae under canines. Canines long and slender. With three denti-setae, distal denti-seta canine-like, middle and proximal denti-setae slender, bifid and pectinate. Medially with one pectinate, spine-like seta and three simple, spine-like setae (dorsolateral insertions); and ca. six long setae, partly with bifurcated tips (bifurcation often difficult to see; ventrolateral insertions). Maxillary palp 3-segmented, ca. 1.7 × as long as length of galea-lacinia; palp segment III ca. 1.6 × length of segment II; setae on maxillary palp fine, simple, scattered over surface of segments I, II, and III; apex of last segment rounded.

Labium (Fig. 7h-k ). Glossa nearly as broad and slightly shorter than paraglossa; inner and outer margins with many short, spine-like setae; apex with two medium, robust setae; dorsal surface with long, fine, simple, scattered setae. Paraglossa curved inward; ventrally with many long setae along outer lateral and apical margin, and row of long, stout, pointed, simple setae along inner lateral margin; dorsal surface with long, fine, simple, scattered setae. Labial palp 3-segmented. Segment III nearly trapezoidal with rounded distal corners, distal margin slightly concave; outer lateral margin with short to medium, fine, simple setae, distal margin with short, spine-like and short, fine, simple setae; ventral surface with medium, fine, simple, scattered setae. Segment II with medium, fine, simple, scattered setae along outer lateral margin and on ventral surface; dorsally with seven or eight short, spine-like setae along distal margin. Segment I with medium, fine, simple setae scattered on ventral surface and on outer lateral margin.

Hind protoptera well developed.

Foreleg (Fig. 8a, b ) very slender. Ratio of foreleg segments 1.6:1.0:1.0:0.4. Femur. Length ca. 5 × maximum width. Dorsal margin with occasional short, spine-like setae, row of short, pointed setae near margin. Apex slightly rounded. Short, stout, pointed setae scattered along ventral margin; femoral patch absent. Tibia. Dorsal margin bare. Ventral margin with row of short, curved, spine-like setae and some aditional stout, pointed setae along margin. Anterior surface scattered with short, stout, pointed, and partly serrate setae along ventral margin. Patellatibial suture present in basal 1/3 area. Tarsus. Dorsal margin bare. Ventral margin with dense row of short, curved, serrate, spine-like setae. Claw with two rows of 17-20 minute denticles each, in basal ca. 1/3 area, increasing in size distally; subapical setae absent.

Terga (Figs 4b, e , 5b ). Posterior margin of terga: I smooth, without spines; II-VI (VII) with small triangular spines; VII-IX with triangular, pointed spines.

Sterna. Posterior margin of sterna I-VI smooth, without spines. Posterior margin of sterna VII-VIII with small, triangular spines.

Tergalii (Figs 8c-i , 9d ). Present on segments I-VII. Costal margins with minute denticles and short, fine, simple setae, anal margins almost smooth. Tracheae extending from main trunk to inner and outer margins. Tergalius I as long as length of segments II and III combined; tergalius IV as long as length of segments V and VI combined; tergalius VII as long as length of segments VIII and IX combined.

Paraproct (Fig. 8j ). With irregular row of 30-45 pointed marginal spines of different size, some with split tips, and few additional spines in second row. Cercotractor with minute, irregular, marginal spines.

Caudalii (Fig. 8k ). Spines at posterior margins of segments short triangular, pointed.

Subimago. Judging from subimaginal tarsomeres developing under cuticle of last instar female larvae, all tarsomeres of all legs of female subimago have pointed microlepids on surface (see Kluge 2022).

Imago. Unknown.

Etymology.

Dedicated to Prof. Majida El Alami, committed researcher on aquatic insects in Morocco, and collector of some of the specimens; in recognition of her substantial contribution to the knowledge of the systematics, ecology, and distribution of Moroccan mayflies.

Biological aspects.

The specimens were collected in calm edge waters, loose substrate, low to moderate current, high temperatures, and sites rich in filamentous algae and mosses (Fig. 6a, b ; El Alami et al. 2022a).

Distribution

(Fig. 6e ). Morocco.

Type-material.

Holotype. Morocco • larva; Oued Kelâa, Akchour; 35°14'32"N, 05°10'10"W; 13.03.2021; leg. S. El Yaagoubi; on slide; GBIFCH00592619, GBIFCH00592620, GBIFCH00592621; MZL. Paratypes. Morocco • 6 larvae; same data as holotype; 2 on slides; GBIFCH00980875, GBIFCH00980876; 4 in alcohol; GBIFCH00975645, GBIFCH00975646; MZL • 7 larvae; Oued Jnane Niche (sup.); 16.03.2014; leg. M. El Alami; in alcohol; GBIFCH00975647; MZL • 12 larvae; Oued Jnane Niche (sup.); 17.05.2015; leg. M. El Alami; 1 on slide; 11 in alcohol; LESCB.

Figures

Figure 4. Larvae, posterior margins of terga. Centroptilum samraouii sp. nov. a tergum III d tergum IV; Centroptilum alamiae sp. nov. b tergum III e tergum IV; Centroptilum luteolum: c tergum III f tergum IV.

Figure 5. Larvae, posterior margins of terga VII a Centroptilum samraouii sp. nov. b Centroptilum alamiae sp. nov. c Centroptilum luteolum.

Figure 6. Habitats and distribution of the new species a, b Centroptilum alamiae sp. nov., habitats a Oued Kelaa (type locality) b Oued Jnane Niche c, d Centroptilum samraouii sp. nov., habitats c Guitna sup. (type locality) d Louar inf. e distribution map.

Figure 7. Centroptilum alamiae sp. nov., larva morphology a labrum (left: ventral view; right: dorsal view) b right mandible c right prostheca d left mandible e left prostheca f hypopharynx and superlinguae g maxilla h glossa and paraglossa (ventral view) i glossa and paraglossa (ventral view) j glossa and paraglossa (dorsal view) k labial palp (left: ventral view; right: dorsal view).

Figure 8. Centroptilum alamiae sp. nov., larva morphology a foreleg b fore claw c tergalius I d tergalius II e tergalius III f tergalius IV g tergalius V h tergalius VI i tergalius VII j paraproct k caudalii, spines on posterior margins of segments.

Figure 9. Centroptilum alamiae sp. nov., larva a habitus, dorsal view b habitus, lateral view c habitus, ventral view d tergalius IV. Scale bars: 1 mm (a-c); 0.1 mm (d).