Neoperla cataractae, 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 : 54-56

21. Neoperla cataractae n. sp.

( Figs. 99–101 )

Type material studied. Holotype ♀ ( NEOP056 ; slides AfrZw 98/01 + egg-top-view slide), 2 paratype ♀: Republic of Sierra Leone, Mti Loma [9°10′N 11°07′W], Cascate DenKale, 800m, 25/26.11.84 W. Rossi ( SMNS, gift R.Fochetti).

Habitus. WL 12.5mm. Head wide, ocelli small and more than their diameter apart, a light brown spot between them. Centre of frontoclypeus ochre with orange tinge, darker than areas next to antennal insertions and to eyes. A pale band behind the occipital suture. Pronotum with pale sides, a vague brown stripe along middle. Raised portions of meso- and metanotum brownish, remainder of body of ochre colour. Antenna and cercus apically infuscate. Wings slightly turbid, no pattern.

Male. Unknown.

Female ( Fig. 99 ). S8 with a projecting brownish lip and in front with marks resembling an anchor pattern with diffuse borders (not shown in figure). Vagina long, membranous, unmodified. SSt coiled and forming ~2.5 rings around the coiled spermatheca (which is not shown in the figure). The base of the SSt is wide, its bare concave side with several oblique folds is long but most of the SSt bears a tight coat of scales.

Egg ( Figs. 100–101 ). ~430*240µm, large, with 11 straight ridges between the collar and a sharp pale eclosion line which is distinct also in optical sections through the chorion. Ridges are blunt, rounded, micropyles in the wide spaces between the ridges are exposed. Chorion with irregular fine punctation visible only at magnification ~400*. The egg is widest near midlength, the diameter of the collar is only 110µm, the egg sides converge in almost straight line. The inward bent rim of the collar has some blunt projections restricting the opening of the collar, the rounded anchor cavity is deep, the anchor is mushroom-shaped. The operculum is a low convex cap, diameter 170µm.

DNA ( Figs. 492–493 ). Only the female holotype from Sierra Leone was sequenced for the COX1 DNA barcode fragment. The species is moderately well supported (73.9/98/0) as sister to N. decorata n. sp. + N. planidorsum n. sp. (49.1/99/91).

Notes. In some characters N. cataractae resembles various species but differs much in others. For example, eggs with similarly few ridges occur in N. camerunensis (End.) , N. lujana Navás and N. luluana Navás , but other details of eggs and female genitalia are very different.

Etymology. The name is a Latin noun in the genitiv case, “of the waterfall”, an allusion to the type locality.

Clade E

The monophyly of clade E is very strongly (99.9/100/100) supported in the DNA sequence data analyses, and the branch leading to this complex is particularly long, indicating the distinctiveness of this lineage ( Figs. 491–492 , 495 ).

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.

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 96–101. Neoperla decorata n. sp. and N. cataractae n. sp., the holotypes. N. decorata: 96, front wing; 97, genital situs, diagrammatic, spermatheca removed; 98, egg. N.cataractae: 99, female genital situs, diagrammatic, spermatheca removed; 100, 101, egg, side view and optical cross section (from a photograph). Scales are 100µm, other figures not to scale. a, anchor; c, collar; mi, micropyle; op, operculum; os, opercular suture; sd, spermathecal duct, SSt, spermathecal stalk, V vagina.