Neoperla sassandrae, 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 : 97-98

40. Neoperla sassandrae n. sp.

( Figs. 217–221 )

Type material: holotype ♀ ( NEOP343 ; Z19/91), 4 ♀ paratypes, République de Côte d'Ivoire: Sassandra R., Soubré [5.76, -6.60], light trap, M. Mühlenberg, 16.8.1970 ( SMNS) .

Habitus. WL 10.5–11.5 mm. Yellow, a small light brown spot between the ocelli. Wings slightly turbid, veins brownish.

Male. Unknown.

Female ( Figs. 217–219 ). S8 with a short transverse subgenital plate. The brown mark on S8 is large and deeply indented in front, caudally it is truncate. Mark sharply subdivided by a transverse pale streak. Vagina basally supported by sclerotised lateral folds, distally regularly rounded, top with distinct oblique folds which are very apparent along the sides. SSt densely scaly, only a short basal stretch bare on concave side. SSt about 4* as long as S8 and vagina. No spines in vagina but many delicate microtrichia caudally from insertion of SSt. Spermatheca coiled.

Egg ( Fig. 220–221 ). Slender, 352*180µm. About 20 straight striae, the bare costae are unusually narrow, the sulci exceptionally wide, with irregular punctures and unmodified micropyles. Operculum parabolic, smooth, punctation fine, unordered. Collar sessile, with 2 rings of cells, anchor cavity deep, anchor mushroom-shaped, with single solid stem.

DNA ( Figs. 491–492 , 496 ). Only the female holotype from Ivory Coast was sequenced with the genome-skimming approach, obtaining 2,742bp of mitochondrial, protein-coding genes. The species is maximally supported (100/100/100) as being nested within N. burgeoni , and further molecular study with nuclear markers is needed to resolve this discrepancy between morphological and molecular characters.

Notes. The status of N. sassandrae n. sp. as a separate species is doubtful. A reduction of the caudal of the three marks on female S8 is characteristic of the burgeoni -complex: in N. burgeoni it is absent and the caudal half of sternite is entirely pale, with straight caudal edge; in N. beta , the caudal mark is small to vestigial. The opposite occurs in N. sassandrae : S8 is covered by a brown mark with only a narrow pale slot in front of the distal part which extends onto the short subgenital plate. The lateral vaginal sclerites, the long SSt and especially the narrow egg costae are also characteristic. However, by DNA it is an early diverging taxon within N. burgeoni and not a distinct species.

Etymology. The name is a noun in apposition in the genitive case referring to the upstream region of the river where the specimens were collected.

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 496. Partial (clades G, H) codon-model maximum likelihood phylogram based on 356 mitochondrial genome and COX1 DNA barcode sequences (all-NT). See Fig. 493 for common details.

FIGURES 217–221. Neoperla sassandrae n. sp., female genital situs and eggs. For better visibility of patterns on S8 the vagina was flipped back, or a safranin stain was applied. Scales are 200µm, 217–219 same scale, 221 not to scale. A, anchor; c, collar; lscl, lateral vaginal sclerite; sa, spermatheca; SSt, spermathecal stalk; su, sulcus.