Neoperla tangana, 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 : 157-159

76. Neoperla tangana sp. nov.

( Figs. 432–438 )

Type material. United Republic of Tanzani a: ♁ holotype: United Republic of Tanzania: Tanga region, W. Usambara Mts., Shukoi river , 24.11.1990, sweep net ( NEOP301 , Slide TZ 13, ZMBN). 1 ♁, paratype: Tanzania, Tanga region W. Usambara Mts., Chumbageni [5.08S, 30.09E], 28.11.1990, sweep net ( NEOP300 , Slide TZ 14, SMNS) .

Presumed females. 2♀, United Republic of Tanzania: Morogoro region, Morogoro, Sokoine University [- 6.852096, 37.657466], 11.11.1990, ZMB’s Tanzania Exped., light trap (slide17.030, ZMBN; slide Z21.32, SMNS)

Male ( Figs. 432–435 ). The middle of T7 is raised, between the lateral borders a sharp angled fold delimits about 1/3 of tergite width which is lowered, stands in front of T8 like a shield and extends down into the intersegmental fold ( Fig. 432 ). T8 with a triangular hook curving forward, with some SB on its front ( Fig. 433 ). Caudally from the hook T8 is soft, as is T9 between the ends of the interrupted antecosta. T9 lacks the usual setose paramedian swellings, the curved slender HT10 processes are short. The mediobasal HT-callus is tongue-shaped and concave.

Penis a faintly sclerotised tube, the distal third is pale and soft ( Fig. 434 ). Eversion of endophallus failed but the armature is clearly visible by transparency. The endophallus is little longer than the penis tube, from the tip to about midlength of the penis there are 2 regular rows of stout conical spines ( Fig. 435 ). Fine spicules and membranous structures near the tip of the endophallus, in the basal half of penis, were not studied.

Female (presumed. Fig. 436 ). S8 unmodified, no pattern, no nail. Vagina slender, in front with some concentric folds and patches of small spinules on either side of SSt. SSt about 1.5* longer than the vagina, width uniform, completely coated with scales, the spermatheca is curled.

Egg ( Figs. 437–438 ). A slender ovoid measuring 365*164µm, the short collar with a single ring of cells. Numerous straight striae, the rough coriaceous surface of costae results from a dense cover of tiny prickles. The sulci are narrow furrows with two lines of micro-punctures, micropyles occur in slender widenings. Striae disappear before reaching the parabolic top of the prickly operculum.

DNA ( Figs. 491–492 , 498). The male holotype and paratype from Tanzania were sequenced with the genome-skimming approach, resulting in 10,935bp of mitochondrial, protein-coding genes. The monophyly of the species is maximally supported (100/100/100), and the species’ sister relationship to N. massevensis n. sp. is very strongly supported (99.2/100/100).

Notes. Sexes were collected in neighbouring regions and are presumedly conspecific, both fit in the N. excisa and N. sjostedti -operational complex. Neoperla transvaalensis and N. tansanica n. sp. which are also known from the area are very different.

Etymology. The name was derived from the region of origin, Tanga.

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.

FIGURES 432–438. Neoperla tangana n. sp.: 432, 433, ♁ abdominal tip, segments, hemitergite 10, cercus and epiproct labeled, not to scale; 434, penis (holotype, NEOP300); 435, distal half of penis (paratype, NEOP301); 436, ♀ genital situs; 437, egg; 438, detail of chorion. Scales are 100µm, unless differently labeled. co, common oviduct; D, debris, dirt; sa, spermatheca; SSt, spermathecal stalk; V, vagina.