Neoperla serrula, 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 : 32

5. Neoperla serrula n. sp.

( Figs. 15 , 25 )

Type material: Republic of Ghana, Holotype ♀ ( NEOP010 ), paratype ♁ ( NEOP009 ):, Volta region, Agumatsa waterfalls, Wli, [0.56°N, 12.86°E, 484m], St. 10, 19.11.1993, Kjaerendsen, light trap ( ZMBN). 4♀ paratypes with the same data ( ZMBN, PZ). 1♀ paratype, Republic of Ghana , Western Region , Ankasa Game Prod. Reserve 16.12.83 J.Kjaerandsen & T. Andersen [Ankasa Game Reserve, 5.25N, - 2.57W] ( ZMBN).

Additional material studied. 1♀, Republic of Cameroon, Makak [3.55, 11.02], 11.–16.XI.72, blacklight, Gruwell ( USNM, Washington) .

Habitus. Indistinguishable from N. costata .

Male ( Fig. 15 ). Externally as for the transvaalensis -group. Penis ( Fig. 15 ) slender, tube relatively strongly sclerotised, also ventrally. Everted endophallus curving ventrad, widening distally until it is about twice as wide as the penis tube, the narrower distal fourth of endophallus points caudad. The armature is composed of slender triangular teeth which form a continuous dorsal band from base to tip. On the widest section of endophallus the spine band is expanded while the ventral side is bare. Terminal section of endophallus narrow surrounded by long spines.

Female. S8 with a very short truncate subgenital plate. Vagina unmodified, no supporting sclerites, dorsally without large folds. SSt strongly curved, pale minute denticles form a narrow band near the thick cuticle of the convex side, from the base to near midlength.

Egg ( Fig. 25 ). 455*215µm, widest near middle, sides converging little towards the conical operculum but much towards the long, distally widening collar ( Fig. 25 ). At the base of the conical operculum the profile has a distinct shoulder. The approximately 12 straight ridges are very high where the egg is widest, lowering towards the collar where they are connected to the high walls of large cells. Operculum and floor of sulci with irregular large rough punctures extending far up on the sides of ridges, their edge appears in side view like a regular saw (detail in Fig. 25 ). Anchor mushroom-shaped.

DNA ( Figs. 491–493 ). Only the female holotype and a male paratype from Ghana were sequenced for the COX1 DNA barcode fragment, which does not differ between the two specimens. The species is placed as sister to N. spectabilis n. sp., N. kalengonis n. sp., N. lujan a Navás, and N. transvaalensis (Enderlein) , but while a close relationship is moderately supported (88.9/76/93), the placement as sister taxon lacks significant statistical support (33.6/56/4).

Etymology. The name is a noun in apposition alluding to the egg ridges which resemble a small fine saw, Latin serrula .

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 11–15. Males in the N. lujana-complex. N. costata n. sp.: 11, male tergites 7–10, dorsal view; 12, artificially everted penis. N. lujana Navás, artificially everted penes: 13, from Cameroon, Etambo R.; 14, from Bayanga (CAR). 15, N. serrula paratype from Ghana (NEOP009).

FIGURES 18–25. eggs of the N. lujana-complex: 18, the N. lujana Navás holotype; 19, from Bayanga (CAR, NEOP019); 20, from Odzala N. P. (NEOP018); 21, top view of egg (D. R. Congo, N of Bukavu) (after Moore 1991). N. costata n. sp.: 22, optical cross section; 23, lateral view of an egg, with enlarged profile of a ridge (Liberia, near Tapeta) to the left hand side; 24, egg from Adamaua. N. serrula n. sp.: 25, egg, an enlarged profile of a ridge (Holotype, NEOP010, Ghana, Agumatsa falls, slide 20.12) to the right hand side. Scales are 100µm, unless differently indicated. Details of costae are to the same scale.