Neoperla camerunensis (Enderlein, 1909)

Zwick, Peter & Zwick, Andreas, 2023, Revision of the African Neoperla Needham, 1905 (Plecoptera: Perlidae: Perlinae) based on morphological and molecular data, Zootaxa 5316 (1), pp. 1-194 : 67-70

25. Neoperla camerunensis (Enderlein, 1909)

( Figs. 112 , 126 , 131–132 , 143–149 )

Ochthopetina camerunensis Enderlein, 1909b: 343 , figs 21, 23.

not Ochthopetina camerunensis — Navás 1912: 403, fig. 2; see N. africana !

Neoperla camerunensis — Zwick 1973a: 502, figs. 70, 71; new combination, lectotype designation, redescription. Ochthopetina haugi Navás, 1916: 51 , fig. 29; new synonymy.

Type material studied: ♀ lectotype O. camerunensis : Kamerun Barombi Conradt \ Type [red] \ Neoperla camerunensis Enderl . ♀ Type [in Enderlein’s hand] det. Dr. Enderlein [print] \ Lectotypus design. P.Zwick 1971 \ Mus. Zool. Polonicum Warszawa 12/45 \ Mus. Zool. Polonicum Warszawa Typus No. 1295; 2♀ paralectotypes, Type numbers 1296 and 1300, respectively with the same data (all in MIZ; pinned genitalia and egg slides on Zelluloid, on the specimen pin).Additional paralectotypes (No. 1296–1299, labelled “Kamerun, Barombi, Conradt”) are misassociated or too damaged for identification, see Notes below .

Holotypus N. haugi : Gabonese Republic: Bas Ogooué entre Lambaréné et la mèr E. HAUG 1901 \ Ochthopetina haugi ♁ Nav. [in Navás’ hand] Navás S.J. det. [green print] \ Type ( MNHN; pinned, genitalia on pinned microslide).

Additional material. Republic of Angola: 1♀, Angola,Dundo, Piège lumineux VIII.53 Carvalho (ex coll. Brinck; slide Z18.04). Republic of Cameroon: 1♀: Kamerun, Mukonje 28.3.–4.4.38 Buhr S.G. ( MfNB). 2♀, 6°8’26.25’’N, 10°6’3-68’’E, NW Reg., Bamenda, Mentchum River contributor 15 km NNW Bafut, 630m asl, 9 Nov.2011, MV-lamp,A.Zwick ( SMNS; NEOP 127, NEOP 128); 1♁: Cameroon, Ekok [5.81N, 8.85E] 24 mi E Tekmo, 650m, 12.X.1966, Ross & Lorenzen ( CASENT 8413093; Z18.52). 1♀, Adamana (Camerun) [red ink] \ africana Klapàlek [print] \ det. P. Zwick 1988 Neoperla sp. 9 [handwriting on photoprint] (genital and egg preparation on glass slide; NMCZ; old egg slide in SMNS). 2♁, Makak, 14–26-XI-1972 filtered black light, J.A.Gruwell ( USNM _ 82A, 86); Libamba [3.55°N, 11.02°E], 10km E of Makak (filtered) black light, J.A.Gruwell: 1♁, 15–17-IX.1973; 1♁, 6–10-XII-1973; 2♁, 10–11-I-1974; 1♁, 2♀, 1–2.iii.1974; 1♁, 19–22-IV-1974 ( USNM, in ETOH, genitalia in microvial or on slide, duplicates also SMNS). 1♁, en route Douda Yaounde FrCam W.Afr. 36 \ Van Zwaluvenburg & McGough ( USNM _27). Democratic Republic of the Congo: 1♀, Coll. Mus. Congo Ruwenzori W. Mutwanga [29.40E, 0.20N] IV 1937 Lisfranc ( MRAC); 2♁, Congo belge: P.N.U. [Upemba] Kaswabilenga (700m) 17-X-1947 Mis. G.F.de Witte, 845a \ Coll. Mus. Congo (ex coll. I.P.N.C.B.) \ Neoperla spio (Newman) Dr. N.Hynes det., 1951 ( SMNS, ex MRAC). 2♁, B. Congo, 39 km S of Walikale [1.47S, 28.07E], 700m, XII-25-57 E.S.Ross & R.E.Leech ( CASENT 8413090 & 91; Z18.48 & 49); 1♁: B.Congo, 23 mi E of Kama [3.52S, 27.12E], 16.8.57, Ross & Leech ( CASENT 8413094, Z18.53); 6♁: B. Congo, 12 ml. N of Matadi [5.85N, 13.46E] VII-28-1957 E.S.Ross & R.E.Leech ( CASENT 8413095; Z18.54). 1♀: Coll. Mus. Tervuren Tschela III-1964 (Fain) coll. H. Schouteden; 1♁: Musée du Congo Boma [-5.850, 13.071] 1933 (Dr. Hallet) (both MRAC). 1♁: B.Congo, 50km S of Tshela [5.01S, 12.96E], 26.7.57, Ross & Leech ( CAS). 1♀: Congo 149 Lámpázáz 11. Feb. 1988. Manyara National Park, camp site (slide Z19.78; HMNH). 1, Congo 149 Lámpázáz 11. Feb. 1988. Manyara National Park, camp site (slide Z19.78); 1, Republic of Kenya, Lake Turkana, Sibiloi National Park [3.92N, 36.18], Koobi Fora Base Camp 14.3.1988 (Slide Z19.76, both HNHM). Federal Democratic Republic of Ethiopia: 9 ♀, Ghibe River 13-14/5-61 215 km from Adis Ababa wooden bridge: road: track to The Crown Prince’s Saw Mill, A.Tj. coll (at light). 3 ♀, Ghibe River (260 km) (at light) 6/5-61 S. Chojnacki leg.; 4♀, Cojeb River [7.059N, 37.366E] 9-11/4-61 at light S. Chojnacki leg. (gift P. Brinck). 2♁ (Z75/2, NEOP 124; + Z16.182, NEOP 123), 1♁ „old slide“, 1♀ (Z16.161 & egg-SEM) 15km NW of Chora, Illubabor prov., 1600m, VII.1973, G. de Rougemont ( SMNS). Gabonese Republic: 1♀, Gabon Moyen-Ogooué Rég., Najolé, Auberge St. Jean, Ogooué R., 0°11’03’’S, 10°46’00’’S 16.12.1993 C.C. Jongkind (slide GAB.01\2; ZMBN). Republic of Ghana: 1♁, Western region, Ankasa game prod. Reserve [5.44N, 2.07W, 47m] 10–16.12.93 St. 12 J. Kjaerendsen & T. Andersen light trap; NUFU-project ( ZMBN, NEOP 125). Republic of Guinea: 2♁, petit affl. du Milo à Kousankoro [near Conakry, 9.53800, -13.67700] 21.10.1984 (gift J.M.Gibon, slide Z16/176). 1♁, no details ( Fig. 17.3 ; slide 18.104). 1♁, Guinea, Riv. Niandan (bassin du Niger) à Bambaya 24.10.1984 J.M.Gibon ( SMNS; slide). République de Côte d’Ivoire: 2♁, Elfenbeinküste, Boa, ca. 10 above entrance into Sassandra [township Sassandra: 5.563N, 6.579W], no date ( SMNS, gift B. Statzner; Afr.86/17); 1♁: Ivory Coast, Cavally R. (blackwater) [township Cavally, Republic of Liberia, near border with Ivory Coast; 6.064N, 7.890W] nr Tai 02.07.1977 ( SMNS, gift B. Statzner; Afr.86/19); 1♀, Côte d’Ivoire, Danané [7.25°N, 8.15°E] \ Muséum Paris 12.1930- IV.1931 CH. Alluaud & P.A.Chappuis ( MNHN, egg slide in SMNS). LIBERIA: 4♁: Liberia, 8 mi NW Belefuanai [7.26N, 9.43W], S fork S.Paul R., 11.8.66, Ross & Lorenzen ( CASENT 8413092; Z18.51). Republic of Sierra Leone: 1♁, Pampana près de Magburaka [8.67°N, 11.96°W], 5.2.89 ( SMNS, gift J.M.Élouard; Z16.80, NEOP 126).

Habitus. WL 10–15mm, Rs with 3–4 terminal branches ( camerunensis lectotype: 12mm, three branches). Yellowish to ochre, a brownish heart-shaped spot between ocelli, sometimes traces of brownish pigment along occipital suture. Flagellum brown, cercus pale. Legs light, or a little infuscated around knees. Wings turbid.

Male. Tergites are similar to N. africana . T 7 in rear half with a triangular sclerite ending in a short narrow process, its raised tip with a few SB. Bottom of vertical rear face with a few SB. T8 with Y-shaped flat sclerite. A transverse line of SB at base of sclerite, some more on the narrow band-like caudal part. T9 unmodified, lateral humps pilose, median furrow distinct, SB mainly on humps. Mediobasal callus of HT10 slender, truncate, tip of HT short, not reaching beyond T9, fairly stout, gently curved outward. Epiproct and sternites unmodified.

Penis ( Figs 143–149 ) tubular, sclerotised, apex curving ventrad, with shallow bare dorsal and ventral notches ( Fig. 145 ). Endophallus twice as long as tube or longer and much thinner, forming a long curved hose ( Fig. 143 ). Near its base the endophallus is often annulate and tends to curl. Two basolateral groups of small slender spinules unite dorsally and form a single row of erect spines which stand at considerable distances from one another (e.g., Fig. 146 ). Ventral face and sides bare.

Female ( Figs. 131–132 ). S8 with three brown maculae that may merge and leave a pale central area ( Fig. 131 , top) or surround a variably distinct anchor pattern. Vagina slender, calyx-shaped, without spines or lateral sclerites. SSt slender, flexible, basal section with longitudinal folds on concave and a narrow spine band on convex side long, distally the entire SSt is scaly. Length of coil very variable, from 1.5 (top of Fig. 132 ) to up to 6 rings ( Fig. 126 ). In relatively short coils there may be an angular projection of the distally widening spine band, in long coils the change is gradual.

Egg ( Figs. 112 , 131 ). Slender, 410*213µm, with few (9 in the camerunensis lectotype, Fig. 131 ) straight ridges, entire surface densely irregularly punctate, punctures small ( Fig. 112 ). Anchor pole narrow, the elongate fused collar with two rings of cells with high walls. A step in the egg profile marks the end of ridges, the conical operculum is highly domed ( Fig. 131 ). Micropyles are exposed, orifice on minute bare swelling ( Fig. 112 ), the micropylar canal directed towards the operculum.

Variation. The SSt varies in length, is flexible, and takes variable positions in the female body. It is distinctly longer than the SSt of N. africana and N. panafricana . The lectotype of N. camerunensis has a long spermathecal coil ( Fig. 131 ), similar specimens are known from several localities, from Ethiopia and Manyara N.P. in the east to near the Gaboon coast (Moyen Ogooué) and West Ghana. Several individuals from Cameroon and the ♀ from Danané ( Ivory Coast) have exceptionally long coils ( Fig. 126 ).

DNA ( Figs. 491–492 , 495 ). A total of six specimens from Sierra Leone, Ghana, Cameroon, and Ethiopia were sequenced, representing most of the geographic spread of this species and providing very strong support (99.4/100/100) for the monophyly of this species. Both sexes are represented .

While monophyletic based on mitochondrial DNA sequence data and morphology, the recognition of N. camerunensis (Enderlein) as a distinct species renders the concept of the above N. panafricana n. sp. paraphyletic (see above). They form a species complex that cannot be resolved with current molecular characters and should be investigated further with a much broader range of nuclear markers than just the mitochondrial COX1. The distinct N. camerunensis is not conspecific with the male holotype of N. panafricana n. sp. from the Republic of South Africa, but future revisions of the species complex will probably require the delineation of additional species.

Notes. Enderlein’s original material is mixed. By the lectotype designation ( Zwick 1973a), former syntypes became paralectotypes (ICZN, Recommendation 74F). Only two of the surviving paralectotypes were correctly associated. Three more are misassociated: N. burgeoni Navás , N. dolium n. sp., and N. africana . The fourth is too damaged to be identified. The drawing of an egg from the N. camerunensis lectotype ( Zwick 1973a, his fig. 71) is too stout (see Fig. 131 ).

The endophallus structure of N. camerunensis is apomorphic. It is much longer and narrower than in the related species, near the base only single spines stand dorsally, at wide distances from each other which is by transparency also visible in contracted penes (e.g., the N. haugi type, Figs. 144–145 ). Distal spines are smaller, stouter, and near the end there are several rows. Spermathecal coils and endophalli are exceptionally long in N. camerunensis ; only N. sjostedti is similar in this respect. In contrast, the endophallus of N. panafricana is barely longer than the penis tube and the base bears dorsally a wide band of many spines ( Figs. 138–142 ).

Only limited fresh material of N. camerunensis was available. DNA-analyses of many old samples failed. Therefore, the molecular analyses ( Figs. 491–492 , 495 ) include only few specimens, but the species is widespread and apparently not rare.

IV.2 The N. pilulifera -complex (~ clade F)

An endophallus with a long bare basal stretch ( Figs. 164 , 177, 179 , bbs) and an armature restricted to the distal section is shared by several males with pyramid-shaped process on T7 and flat or only slightly convex T8. Endophallus variable, recurrent tube never observed.

Females usually have an anchor pattern on S8. Concertina-like transverse folds at the base of the vagina suggest it can be much extended (e.g., Figs. 154 , 167 , cf). SSt covered with densely placed scales, length variable, between half and 1.5 circles are formed. The non-striate, smooth, and finely punctate eggs often resemble pills and are characteristic of the complex. Identification of females largely relies on eggs and is difficult.

Generally, in species with striate eggs the ends of costae are connected to cells on the collar. Several of the species have cells on the projecting collar ( Figs. 183, 185 ), probably their ancestors had striate eggs.

The monophyly of the N. pilulifera -complex excluding N. pusilla sp. n. and N. multiserrata sp. n. (= clade F) is strongly supported (100/98/7) in the DNA sequence data analyses.

Keys to species

Males ( N. nichollsi , N. plicata , and N. cataractae unknown)

1 The penis is a very slender tube ( Figs. 153 , 172 )............................................................. 2

1' The penis is not strikingly slender, shape varies and may be rather short and wide.................................. 4

2 There are no external spines on the penis tube............................................................... 3

Figures

FIGURE 491. Codon-model maximum likelihood phylogram based on 83 largely complete mitochondrial genome sequences only (mt-NT). Statistical support values (SH-aLRT, UFBoot) from this and other analyses summarised by squares as explained in the figure. Terminal labels include information on the species, type status, gender, originating country, unique sequence identifier (NEOP###), sequencing approach and total basepairs of 13 mitochondrial, protein-coding genes. Clades of particular interest highlighted with colours that correspond to the clades in other trees. HT = holotype; PT = paratype; PCR = Polymerase Chaine Reaction; WGS = Whole Genome Shotgun.

FIGURE 492. Simplified overview of codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). Terminal labels include information on the species only. Clades of particular interest highlighted with colours that correspond to the clades in other trees. The full tree is shown in Figs 493-498.

FIGURE 495. Partial (clade E) codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). See Fig. 493 for common details.

FIGURES 108–113. Neoperla spp., structural details.108, N. africana Klap., 109, N. kalengonis n. sp., 110, N. sjostedti needhami Lestage, all from the stream Kalengo: 108, 109 scales in the SSt. Close-ups of egg chorion: 110, three egg striae, the 2 rows of micropunctures in the sulci diverge around an island with a micropyle; 111, N. africana, 112 N. camerunensis (End.), chorion with 2 micropyle orifices; 113, processes of tergites 7 and 8, and modifications of antecosta 8 (AC8), a combination of inner structures (light grey), and of fine pilosity and sclerites (dark grey) on the surface of tergites; diagrammatical. The SEM microgaphs are courtesy of MPI of Limnology, PL̂n.

FIGURES 123–126. Neoperla africana-group, female genital situs and spermathecal stalk: N. africana Klapálek: 123, Ghana, Subri R., vagina and spermathecal coil folded back from S8, for better visibility of anchor spot on S8. N. panafricana n. sp.: 124, Waterberge, Mapote Farm. N. camerunensis (Enderlein): 125, Ethiopia, Ghibe R.; 126, Cameroon, Bamenda, NEOP128. Scales are 100µm. am, anchor mark; ap, angular projection; lf, longitudinal folds; lscl, lateral vaginal sclerite; tf, transverse folds; SSt, spermathecal stalk; V, vagina.

FIGURES 131–134. Neoperla spp., female situs in the top row, an egg of the same specimen in the bottom row: N. camerunensis (Enderlein):131, the lectotype (situs after Zwick 1973a); 132, ♀ from Cameroon, Libamba. N. panafricana n. sp.: 133, Namibia, Kunene R. (NEOP133); 134, Senegal, Touba (NEOP130). All to similar scales. ap, angular process; lf, longitudinal folds; od, oviduct; sa, spermatheca; SSt, spermathecal stalk; V, vagina.

FIGURES 143–149. Neoperla camerunensis (Enderlein), penes and everted endophalli: 143, from Makak, endophallus not completely everted (USNM_086); 144, 145, holotype of the synonymous N. haugi from Lambaréné, before and after artificial eversion of endophallus; 146, penis tip with protruding base of endophallus, specimen from Ghana,Ankasa Reserve (NEOP125). 147, Congo, Boma (Z19.035); 148, Ivory Coast, Cavally R.; 149, Ethiopia, Cojeb R. (NEOP123). Figs. 146–147 to the same scale, the others to a scale similar to Fig. 143. so, soft ventrobasal region of penis tube.

FIGURES 16–17. Female genital situs: 16, N. lujana Navás, not to scale; 17, N. costata n. sp. (Liberia, near Tapeta). co, common oviduct; scl, sclerite in vagina; sd, spermathecal duct; SSt, spermathecal stalk; V, vagina.

FIGURES 135–142. Neoperla panafricana n. sp., male abdominal tip and penis with everted endophallus: 135–137, holotype from Mkozi R. NEOP158; 138, Guinea (no details); 139, Namibia, Kunene R.; 140, R. S. Afr., Legalameetse, NEOP154; 141, Ivory Coast, Férédougouba; 142, Senegal, Touba, NEOP131. The scale is 200µm, all penes to similar scales.

FIGURES 161–168. Neoperla amoena n. sp.. ♁ holotype: 161–163, habitus and abdominal tip (not to scale; NEOP070); 164–166, penis, only 164 to scale; ♀ paratype from Bamako: 167, 168, genital situs and egg. Scales are 100µm. bbs, bare basal stretch; tf, transverse folds; sa, spermatheca; SSt, spermathecal stalk; V, vagina.

FIGURES 177–180. Neoperla aethiopica n. sp. and N. occulta n. sp.. N. aethiopica: 177, penis of holotype (NEOP074); 178, enlarged distal section of the endophallus of the paratype. N. occulta: 179, distal half of penis with everted endophallus (Bayanga LP1); 180, distal part of contracted penis (Bayanga PJ, NEOP058). The curved line connects corresponding structures. Scales are 100µm. bbs, bare basal stretch; bl, basolateral, dd, dorsodistal, dl, dorsolateral spine groups.

FIGURES 154–160. Neoperla plicata n. sp. and N. pirus n. sp.. N. plicata: 154, female from Makokou, genital situs, genitalia flipped back from S8 which is shown upside down; 155, egg of same; 156, diagrammatic section through anchor pole of same; 156 egg of ♀ from Odzala N. P.. N. pirus: 158, genital situs and egg of ♀ holotype, plus semitransparent detail of a second egg (NEOP064). Scales are 100µm. a, anchor; c, collar; cf, concertinated transverse folds; ls, lateral sclerite; sa, spermatheca; SSt, spermathecal stalk; V, vagina.

FIGURES 181–192. ♀♀ of the Neoperla pilulifera-complex. N. pilulifera n. sp.: 181, genital situs, ♀ from Ghana, Ankasa Reservation; 182, egg of same, arrows show micropyles; 183, 184, collar and micropyle of ♀ from Gabun, Belinga; 185, “teleskoping” collar of ♀ from Schouteden, Koteh / Belinga. N. occulta n. sp.: 186, 187, genital situs and egg, Central African Republic, Bayanga. N. nichollsi n. sp., 188–192: 188, 189, genital situs and egg (Liberia, 8 mi NW Belefuanai, S fork S.Paul R., 11.8.66, Ross & Lorenzen diagrammatic, from photographs) (NEOP057); 190–192 are anchor pole regions of an intact and of 2 teratological eggs, all from the same ♀. In 186–188 ♀ situs and eggs to the same scales, respectively. The scale in 181 is 100µm, others figures as indicated, or not to scale. a, anchor; od, oviduct; rd, receptacular duct; sa, spermatheca; SSt, spermathecal stalk.

FIGURES 150–153. Neoperla caeleps n. sp., male HT (NEOP068) from Loffa: 150, abdominal tip, tergites numbered, not to scale, 151, apex of partly everted penis, the scale is 100µm. 152, paratype from Ghana (NEOP067). 153, PT from Lolodorf, everted penis. 151, 152 to the same scale. ce, cercus; E, epiproct; HT10, hemitergite 10.

FIGURES 169–176. ♁♁ in the Neoperla pilulifera-complex. N. pilulifera n. sp.: 169, 170, abdominal tip, dorsal and lateral, semi-diagrammatic, tergites and hemitergite 10 labelled; 171, contracted, 172, everted penis; 173, distal half of penis tube and base of endophallus (holotype ♁): all from Bayanga. N. crustata n. sp.: 174, 175, ♁ from Mali, Niger at Bamako; by transparency of the slide mount the basal end of the distodorsal spine group seems to overlap with the far distally displaced basolateral spine group (encircled); 176, holotype from Guinea (NEOP073). 174 and 178 to the same, other figures not to scale. bbs, bare basal stretch; bl, basolateral, dd, distodorsal, dl, distolateral spines.