Centroptilum samraouii 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

publication ID	https://dx.doi.org/10.3897/zookeys.1131.91017
publication LSID	lsid:zoobank.org:pub:EF181E5C-2947-41A1-9594-2756591C9A7F
persistent identifier	https://treatment.plazi.org/id/C04FC672-92F6-4E55-8B48-FB4D5BDD93BD
taxon LSID	lsid:zoobank.org:act:C04FC672-92F6-4E55-8B48-FB4D5BDD93BD
treatment provided by	ZooKeys by Pensoft
scientific name	Centroptilum samraouii Kaltenbach, Vuataz & Gattolliat
status	sp. nov.

Treatment

Centroptilum samraouii Kaltenbach, Vuataz & Gattolliat sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 , 4a, d View Figure 4 , 5a View Figure 5 , 6 View Figure 6

Differential diagnosis to other species of Centroptilum .

Larva. Following combination of characters: A) labrum with anterior margin nearly straight; ratio width vs. length ca. 1.6 × (Fig. 1a View Figure 1 ); B) maxillary palp ca. 1.9 × as long as galea-lacinia, segment III apically pointed; segment III ca. 1.3 × as long as segment II (Fig. 1g View Figure 1 ); C) inner distal margin of labial palp segment III concave (Fig. 1j View Figure 1 ); D) dorsal margin of fore femur with occasional short, spine-like setae (Fig. 2a View Figure 2 ); E) fore tarsus slightly longer than tibia (1.1 ×; Fig. 2a View Figure 2 ) F) claw with two rows of denticles, each with ca. 20 small to minute denticles (Fig. 2b View Figure 2 ); G) paraproct with 17-23 pointed spines, plus some additional submarginal spines (Fig. 2j View Figure 2 ).

Description.

Larva (Figs 1 View Figure 1 - 3 View Figure 3 , 4a, d View Figure 4 , 5a View Figure 5 ). Body length 3.8-4.2 mm. Cerci: ca. 2/3 of body length. Paracercus: nearly as long as cerci. Antennae reaching apex of fore protoptera.

Colouration (Fig. 3a, b View Figure 3 ). Head, thorax and abdomen dorsally brown, with dark grey-brown pattern as in Fig. 3a View Figure 3 . Head and thorax ventrally brown, with dark grey-brown lateral marks on thorax (Fig. 3b View Figure 3 ). Abdomen ventrally light brown. Legs light brown, apex of femur and claw darker. Caudalii ecru, brown annulated.

Labrum (Fig. 1a View Figure 1 ). Rectangular, width ca. 1.6 × maximum length. Distal margin with broad, angulated, medial emargination. Anterior margin nearly straight. 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. seven short, stout setae near lateral and anterolateral margin.

Right mandible (Fig. 1b, c View Figure 1 ). Incisor and kinetodontium separated. Incisor with three denticles; kinetodontium with two denticles. Prostheca stick-like, distally with two 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. 1d, e View Figure 1 ). Incisor and kinetodontium separated. Incisor with four denticles; kinetodontium with three denticles. Prostheca stick-like, distally 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. 1f View Figure 1 ). 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. 1g, h View Figure 1 ). Galea-lacinia ventrally with 3-5 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 two simple, spine-like setae (dorsolateral insertions); and ca. eight long setae with bifurcated tips (bifurcation often difficult to see; ventrolateral insertions). Maxillary palp 3-segmented, ca. 1.9 × as long as length of galea-lacinia; palp segment III ca. 1.3 × length of segment II; setae on maxillary palp fine, simple, scattered over surface of segments I, II, and III; apex of last segment pointed.

Labium (Fig. 1i, j View Figure 1 ). 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 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 5-7 short, spine-like setae along distal margin. Segment I with medium, fine, simple setae scattered on ventral surface.

Hind protoptera well developed.

Foreleg (Fig. 2a, b View Figure 2 ) very slender. Ratio of foreleg segments 1.6:1.0:1.1:0.4. Femur. Length ca. 5 × maximum width. Dorsal margin with occasional short, spine-like setae. 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 additional stout, pointed setae along margin. Anterior surface scattered with few stout, pointed, and partly serrate setae along ventral margin. Patellatibial suture present in basal ¼ 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 4a, d View Figure 4 , 5a View Figure 5 ). Posterior margin of terga: I smooth, without spines; II with rudimentary spines; III with small, triangular spines; IV-IX with triangular spines.

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

Tergalii (Figs 2c-i View Figure 2 , 3c View Figure 3 ). 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-IV 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. 2j View Figure 2 ). With 17-23 pointed marginal spines of different size, and some additional spines in second row. Cercotractor with minute, irregular, marginal spines.

Caudalii (Fig. 2k View Figure 2 ). Spines at posterior margins of segments elongated triangular with long points.

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. Boudjéma Samraoui, committed researcher on aquatic insects in Algeria, and collector of the new species; in recognition to his substantial contribution to the knowledge of the ecology and distribution of Algerian mayflies.

Biological aspects.

Centroptilum samraouii sp. nov. occupies the headwaters of steep, narrow and intermittent streams (Fig. 6c, d View Figure 6 ; Samraoui et al. 2021b, c).

Distribution

(Fig. 6e View Figure 6 ). Algeria.

Type-material.

Holotype. Algeria • larva; Guitna sup., Ghora; 36°36'42"N, 08°21'19"E; 22.01.2020; leg. B. Samraoui; on slides; GBIFCH00592552, GBIFCH00592551, GBIFCH00592622; MZL. Paratypes. Algeria • 2 larvae; Guitna sup., Ghora; 36°36'42"N, 08°21'19"E; 05.11.2019; leg. B. Samraoui; on slides; GBIFCH00895417, GBIFCH00895418; MZL • 3 larvae; Guitna sup.; 36°36'42"N, 08°21'19"E; 09.10.2019; leg. B. Samraoui; on slide; GBIFCH00592553; 2 in alcohol; GBIFCH00975620, GBIFCH00975623; MZL • larva; Louar inf., Ghora; 36°37'03"N, 08°22'49"E; 05.11.2019; leg. B. Samraoui; on slide; GBIFCH00592555; MZL • larva; Algeria; Guitna inf.; 07.11.2018; leg. B. Samraoui; in alcohol; GBIFCH00975621; MZL.