Baetis rifensis El Yaagoubi, Vuataz & Gattolliat, 2023

El Yaagoubi, Sara, Vuataz, Laurent, El Alami, Majida & Gattolliat, Jean-Luc, 2023, A new species of the Baetis fuscatus group (Ephemeroptera, Baetidae) from Morocco, ZooKeys 1180, pp. 27-50 : 27

Baetis rifensis El Yaagoubi, Vuataz & Gattolliat sp. nov.

Figs 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9

Type materials.

Holotype. Morocco • 1 nymph; Tetouan Province, S1 Oued El Hamma, Loc. Jbel Laalam; 35°23'23.2"N, 5°29'57.2"W; alt. 200 m; 20.II.2022; El Yaagoubi leg.; DNA; GBIFCH01144399; MZL.

Paratypes. Morocco • 38 larvae; same data as holotype; 25.III.2023; El Yaagoubi leg.; 3 on slide; 35 larvae on alcohol; LESCB • 19 nymphs; same data as holotype; 20.IV.2021; El Yaagoubi leg.; 2 on slide; LESCB and 1 larva for DNA; GBIFCH01144184; MZL • 6 nymphs; Tetouan Province, S2 Oued Taida, Loc. Beni idder; 35°22'6.10"N, 5°32'16.99"W; alt. 507 m; 28.IV.2017; El Alami leg.; DNA; GBIFCH01144398; MZL • 1 larva; Tetouan Province, S2 Oued Taida, Loc. Beni idder; 35°22'6.10"N, 5°32'16.99"W; alt. 507 m; 04.VI.2014; El Bazi leg.; LESCB • 8 nymphs; Chefchaouen Province, S3 Oued Kelaa, Loc. Akchour; 35°14'25.6"N, 5°9'46.7"W; alt. 460 m; 13.III.2021; El Yaagoubi leg.; 1 on slide; LESCB; DNA; GBIFCH01144199; MZL • 7 larvae; Chefchaouen Province, S3 Oued Kelaa, Loc. Akchour; 35°14'25.6"N, 5°9'46.7" W; alt. 460 m; 20.IX.2014; Khadri leg.; LESCB • 6 larvae; Chefchaouen Province, S4 Oued El Kannar I, Loc. Souk Lhad; 35°13'1.7"N, 5°1'24.02"W; alt. 105 m; 17.V.2014; Khadri leg.; LESCB • 4 larvae; Chefchaouen Province, S5 Oued El Kannar II, Loc. Assoul; 35°13'17.0"N, 5°0'47.2"W; alt. 68 m; 18.VI.2014; Khadri leg.; LESCB • 2 larvae; Chefchaouen Province, S6 Oued Bouhiya, Loc. Silloufene; 35°17'53.4"N, 4°58'26.3"W; alt. 35 m; 17.V.2014; Khadri leg.; LESCB • 1 larva; Chefchaouen Province, S7 Oued Amter I, Loc. Amter; 35°13'44.3"N, 4°48'42.9"W; alt. 40 m; 17.III.2014; Khadri leg.; LESCB • 5 larvae; Chefchaouen Province, S8 Oued Amter II, Loc. Amter; 35°14'39.6"N, 4°48'12.6"W; alt. 10 m; 17.III.2014; Khadri leg.; LESCB • 4 larvae; Chefchaouen Province, S9 Oued Ouringa I, Loc. Jebha; 35°8'03.4"N, 4°42'9.4"W; alt. 95 m; 17.III.2014 • 1 larva; same data as holotype; 17.V.2014; Khadri leg.; LESCB • 3 larvae; Chefchaouen Province, S10 Oued Ouringa II, Loc. Jebha; 35°10'14.2"N, 4°41'47.6"W; alt. 60 m; 17.V.2014; Khadri leg.; LESCB • 7 larvae; Chefchaouen Province, S11 Oued Ouringa III, Loc. Jebha; 35°11'11.2"N, 4°41'13.5"W; alt. 25 m; 17.III.2014; Khadri leg.; LESCB • 1 larva; same data as holotype; 17.V.2014; Khadri leg.; LESCB • 3 larvae; Chefchaouen Province, S12 Oued Mlilah, Loc. Derdara; 35°2'35.0"N, 5°21'13.0"W; alt. 198 m; 9.V.2015; El Bazi leg.; LESCB • 6 nymphs; Chefchaouen Province, S13 Oued Mansoura, Loc. Tanaqoub; 35°5'16.0"N, 5°30'37.0"W; alt. 124 m; 1.IV.2021; El Yaagoubi leg.; 1 on slide; LESCB; DNA; GBIFCH01144168; MZL • 6 larvae; Larache Province, S14 Oued Sghir, Loc. Béni Arouss; 35°16'1.63"N, 5°37'10.9"W; alt. 200 m; 02.V.2022; El Yaagoubi leg.; LESCB.

Description.

Larva (Figs 2 - 9 ). Female body length 6.0-7.8 mm; cerci 2.0-2.8 mm; median caudal filament ca 2/3 of cerci. Male body length 6.0-7.2 mm; cerci 2.2-2.8 mm; median caudal filament ca 2/3 of cerci.

Colouration (Fig. 2a-c ): general colouration yellowish brown. Head uniformly brown with vermiform, yellow marking along epicranial suture, sometimes diffused and inconspicuous. Pronotum brown with dispersed swirling yellowish marks. Mesonotum brown with yellowish spots. Legs pale yellow, with a yellowish-brown patch in centre of femur and a submarginal darker stripe near outer margin of femur. Abdominal tergites medium brown and pale yellow with two central, darker brown spots: tergite I yellow; tergites II-IV brown with lateral yellow spots; tergite V yellow with lateral brown spots; tergites VI-VIII brown, yellowish distolaterally; tergites IX-X yellow; tergite X brownish apically. Cerci and paracercus yellowish or whitish yellow, with a conspicuous, dark transversal band near middle and darker apically. Basal segments sometimes also darker.

Labrum (Fig. 3a, b ) with 1 + (5-6) long setae, almost symmetric, evenly rounded laterally, and about 1/3 broader than long. Dorsal surface (Fig. 3a ) scattered with long, pointed setae; ventral surface with apicolateral patch of long, bifid setae near margin (Fig. 3b ).

Right mandible (Fig. 4a, b ): incisor and kinetodontium fused. Incisor with three apically rounded or pointed teeth subequal in size; outer tooth slightly broader. Kinetodontium with four teeth; inner margin of innermost tooth denticulate. Prostheca slender, apically pectinate.

Left mandible (Fig. 4c, d ): incisor and kinetodontium fused. Incisor with three apically rounded or pointed teeth subequal in size; outer tooth slightly broader. Kinetodontium with three teeth; inner margin of innermost tooth denticulate. Prostheca robust, apically with stout denticles and a comb-like structure.

Maxilla (Fig. 5a, b ): galea-lacinia ventrally with two simple setae under teeth. Inner dorsal row of setae with three denti-setae; distal denti-setae tooth-like; middle and proximal denti-setae slender, bifid, and pectinate.

Maxillary palp (Fig. 5c ) slightly longer than length of galea-lacinia; palp segment II 1.2 × length of segment I; setae on maxillary palp fine, simple, scattered over surface; apex of last segment rounded.

Hypopharynx and superlinguae (Fig. 5d ): Lingua trilobed, apically covered with thin setae; superlingua subequal to lingua. Lingua longer than broad; medial tuft of stout setae well developed, broad; distal half laterally expanded; fine, long, simple setae along distal margin.

Labium (Fig. 6a, b ): glossa shorter than paraglossae; distal and lateral margins with long stout simple setae. Paraglossa (Fig. 6b ) apically with three rows of long, simple, stout setae; dorsal surface with a row of five long, stout setae. Labial palps with a distinctly curved outer margin with segment I 0.7 × length of segments II and III combined, segment II 1.2 × length of segment I; fine, simple setae scattered over surface of segments I and II; segment II with a small, digitiform, apical projection; segment III slightly asymmetric, broadly rounded and about 1.5 × broader than long; covered stout medium setae (Fig. 6a ).

Foreleg (Fig. 7a-e ): ratio of foreleg segments 1.2:0.8:0.6:0.4. Femur (Fig. 7b ) length 3.5 × maximum width. Dorsal margin with spatulate setae (Fig. 7c ), very abundant proximally, scarce distally; ventral and lateral with scattered short stout setae. Tibia: dorsal margin almost bare; ventral margin with short, stout, apically pointed setae (Fig. 7d ), and some fine, simple setae. Tarsus: dorsal margin almost bare; ventral margin with row of curved, short to medium-length spine-like setae. Claw (Fig. 7e ) with one row of 12-14 denticles, distally pointed; subapical setae absent.

Abdominal terga (Fig. 8 ): surface covered by scale bases and a few setae. Distal margins of tergites with triangular, pointed spines, longer than wide.

Paraproct (Fig. 9a ): surface with few scale bases and broad setae; margin with ca 20 long, slender spines. Cercotractor, margin with ca 15 medium-length spines.

Protogonostylus (Fig. 9b ): subimaginal gonostyli developing under cuticle of last instar larvae folded in the following way: segment II bent towards middle, last segment bent laterally.

Gills (Fig. 9c ): tracheae extending from main trunk to inner and outer margins. Serrated costal margin without spine-like setae.

Imagos. Unknown.

Subimago. Unknown.

Etymology.

The new species is named after the Moroccan Rif region, from where it was collected for the first time.

Distribution.

Morocco: Rif (Fig. 1 ).

Biology.

The specimens were captured from rocky bottoms of moderate- to slow-velocity streams and from rhithral to potamal portions of rivers.

Molecular analyses

The COI data set was>95% complete and included 31% of parsimony-informative sites. Pairwise COI distances across all sequences ranged from 0 to 21.8%. The overall mean p -distance within MOTUs was 0.8% (mean range 0-2.1%), while the overall mean p -distance between MOTUs was 15.4% (mean range 3.2-21.7%). The maximum p -distance within MOTUs varied from 0 ( Baetis sp. 2 and B. fuscatus 5) to 4.3% ( B. fuscatus 1). The minimum p -distance between MOTUs ranged from 3.2% ( B. rifensis sp. nov.- B. sp. 1 and B. rifensis sp. nov.- B. sp. 2) to 12.2% ( B. rifensis sp. nov.- B. scambus ). The five sequences from B. rifensis sp. nov. formed a strongly supported monophyletic clade, identified as a distinct MOTU in both the ASAP and mPTP species-delimitation analyses (Fig. 10 ). The two species-delimitation methods were largely concordant for the other MOTUs, except for the B. fuscatus sensu lato (s.l.) clade, which was split into five and eight MOTUs according to the ASAP and mPTP methods, respectively.

Figures

Figure 1. Distribution of Baetis rifensis sp. nov. (yellow star: type locality).

Figure 2. Baetis rifensis sp. nov., larva habitus a female, dorsal view b male, dorsal view c male, lateral view.

Figure 3. Baetis rifensis sp. nov., larva morphology a labrum dorsal face b labrum ventral face.

Figure 4. Baetis rifensis sp. nov., larva morphology a, b right mandible c, d left mandible.

Figure 5. Baetis rifensis sp. nov., larva morphology a maxilla b apex of maxilla, c apex of maxillary palp, d hypopharynx.

Figure 6. Baetis rifensis sp. nov., larva morphology a labial palp b paraglossae.

Figure 7. Baetis rifensis sp. nov., larva morphology a leg b femur c femur dorsal margin d tibia ventral margin e claw.

Figure 8. Baetis rifensis sp. nov., larva morphology abdominal terga V.

Figure 9. Baetis rifensis sp. nov., larva morphology a paraprocts b protogonostylus c gill.

Figure 10. Bayesian (BEAST) maximum clade credibility COI tree of the Baetis fuscatus group in the Western Palaearctic. Coloured vertical boxes indicate species-delimitation hypothesis (i. e., MOTUs) according to the mPTP and ASAP methods. For each ASAP-based MOTU, the corresponding species names (where available) and the country / region of origin are provided, with the newly described species specified in bold and the associated GBIF codes highlighted in pale pink. Tips labelled with GBIF codes indicate newly sequenced specimens; PT 002, ES 029, and ES 030 codes designate sequences from the project FREDIE; the GMGMQ 2692 - 18 code is from BOLD; the other codes correspond to sequences obtained from GenBank. The three lineages, Baetis rifensis sensu lato (s. l.), Baetis scambus s. l., and Baetis fuscatus s. l., are labelled above or below their respective branches. Circles on branches indicate Bayesian posterior probabilities> 0.9.