Neoperla spectabilis, Zwick & Zwick, 2023

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 : 36-38

9. Neoperla spectabilis n. sp.

( Figs. 42–49 )

Type material studied: Republic of Cameroon: Holotype ♀, Kamerun Ekona [4°40’N, 9°20’E] 17.4.- 20.5.1938 Buhr ( MfNB, slide Z19.001; NEOP007 ) . Paratypes: Republic of Cameroon: 1 J, Sappo , Buea [4.1387N, 9.2433E], British Cameroons, IV-21 S.Tita (gift P.Brinck, SMNS) . Republic of Equatorial Guinea: 1 J, Is. Fernando Poo [Bioko], Musola [~ 3.43N, 8.60E] 800 m. s.m. L.Fea (Mus. Genova, pinned, genitalia on pinned plastic slide) .

Habitus. WL of male 10.8–11.5mm, 16.0mm in the female. Pale yellow, a black spot between ocelli. Flagellum brown, tibiae basally from subgenual organ and tips of tarsi slightly infuscate. First two branches of Rs on common stalk, anterior branch forked or not, posterior branch connected to M by crossveins. Ocelli small, just over 1 diameter apart.

Male ( Figs. 42–45 ). T7 with a faintly expressed caudal sclerite ending in a small pointed process with slightly convex underside from which single SB project in dorsal view. T8–T10 as for the group. Mediobasal callus of HT10 rounded, HT10 process slender, narrowing towards the blunt tip. Process nearly straight in dorsal view, tip gently upcurved in side view. Sternites without setal fringes.

Penis ( Figs. 43–45 ) large and wide, membranous except for a triangular dorsal sclerite extending from base to near half length ( Fig. 43 , ds). A pair of swellings ( Figs. 43, 45 , sw) at the ventrodistal edge of the tube is beset with fine triangular teeth. A short basal section of endophallus is bare, more distally sides and ventral face bear large flat hooks with abruptly back-curved tip ( Figs. 43–45 , arrows), distal hooks are successively smaller. Convex dorsal side of endophallus with slender needle-like spines (sp in Fig. 43 ) which are inconspicuous near base but form a fairly dense distal band.

Female ( Fig. 46 ). S8 caudally pale brownish and slightly projecting, with a median kink. Vagina long, with almost parallel sides, near midlength with numerous scales, their sharp tips point caudo-mediad. The SSt inserts far in front and bears many strong folds on its back. SSt first directed cephalad, this section with many undulating folds inside. The SSt is then bent back abruptly and becomes a wide slender tube with very fine pale spinules. The narrow tip supports the curled spermatheca in central position.

Egg ( Figs. 47–49 ). Drum-shaped, the low operculum is covered with deep irregular grooves ( Figs. 47, 49 ). The funnel-shaped collar is long, its surface is smooth, the rim flanged and scalloped, the anchor mushroom-shaped. Sides with ~20 striae which are oblique, nearly levogyrous. Costae bear high flanges which are folded sideward and conceal the sulci ( Fig. 48 , cf). Sulci have a wide floor subdivided by little transverse ridges, sulci end in a transverse cell, cells form a ring of long cells around the base of the operculum (bd in Fig. 48 ). Micropyles were not observed.

DNA ( Figs. 491–493 ). Only the female holotype from Cameroon was sequenced with the genome skimming approach, but only 2,049bp of the mitochondrial, protein-coding genes could be assembled. It is strongly supported (mt-NT; poorly in all-NT with 75.7/57/5) as sister to N. kalengonis n. sp. + N. lujana Navás.

Etymology. The Latin adjective spectabilis , remarkable, striking, alludes to the exceptional genitalia and egg.

Notes. Genders are thought to be conspecific because there were no competing candidates at the collecting sites. Male and female genitalia of N. spectabilis fit in the N. transvaalensis -group. Figure 43 was prepared during manipulation of the penis when macerated tissue still inflated and strongly bent the organ. The completely cleared penis is curved only little ( Fig. 45 ). The large flat hooks with angularly back-bent tip stand opposite long needle-like spines on the endophallus, the configuration is distinctive, the large hooks of N. laticollis are of different shape and there are no slender needle-like spines. The long flanges on the egg costae resemble some N. dubia , but overall egg shape, collar, and many more characters are very different. Sulci with cells separated by little ridges, and the long peripheral cells separating striae and operculum resemble N. pallidogigas .

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 493. Partial (outgroup, clades A, B, D) codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). Statistical support values above branches or near nodes are SH-aLRT and UFBoot for the codon-model analyses, followed by NT123 UFBoot. 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. See Fig. 492 for an overview. HT = holotype; PT = paratype; PCR = Polymerase Chaine Reaction; WGS = Whole Genome Shotgun.

FIGURES 42–49. Neoperla spectabilis n. sp. Male paratype from Bioko:42, abdominal tip, dorsal view, tergites 7–9 numbered; 43, artificially everted over-inflated penis; 44, enlarged detail of same. 45, penis of male from Cameroon. Female holotype: 46, vagina and spermathecal stalk, diagrammatical, limit between sternites S7 and S8 indicated; 47, egg; 48, chorion fragment with part of the operculum (op) and the flanged costae (not to scale); 49, detached operculum, top view, same scale as 47. bd, border between operculum and flanged costae; cf, costal flange; op, operculum; ds, dorsal sclerite; sa, spermatheca; sp, spicules; SSt, spermathecal stalk; sw, disto-lateral swelling on penis tube. Arrows indicate hooks with bent tip.