IV.4 The Neoperla orthonema -complex (= clade H)

The N. orthonema -complex is proposed for three West African species whose ovoid eggs at first glance seem to have a mushroom-shaped anchor. However, the delicate cap rests on several filaments which rise directly from the anchor cavity and form a curled bundle under the cap. When the anchor attaches to some substrate the filaments stretch out and turn into long threads, the cap is then no longer visible (Fig. 302).

Egg striae differ between the species, those of N. filamentosa n. sp. are levogyrous and resemble the N. sjostedti - and N. arambourgana complex with extremely narrow sulci with a row of micropunctures on each side (Fig. 307). In N. orthonema n. sp. and N. spironema n. sp. eggs have no typical sulci but two kinds of raised ridges, with the micropyles on top of the lower ridges (Fig. 312). Both of these characters are unique in Neoperla .

Female S8 have a large brown spot enclosing a pale anchor pattern (e.g., Fig. 301). The slightly sclerotised caudal segment edge has a shallow bare notch (Fig. 305). The vagina has spines next to the attachment of the SSt which forms 2–3 rings with a dense coat of triangular scales, and the floor of the vagina is roughened by microscopic spinules. We cannot distinguish females without eggs, the eggs differ between species. The>20 to approximately 30 striae are straight in N. orthonema n. sp. but are levogyrous spirals in N. filamentosa n. sp. and N. spironema n. sp. .

DNA (Figs 491–492, 496). The N. orthonema -complex (= clade H) is maximally supported and genetically very distinct as indicated by the length of its branch. It is very strongly supported (92.3/100/100) as sister to N. benti n. sp., and together they are strongly supported (65.7/100/90) as sister to the extensive N. spio -complex (~ clade G). The morphology-based concept of the N. orthonema -complex (= clade H) renders the extensive N. burgeoni - complex (~ clade G) paraphyletic but including N. benti sp. n. in the N. orthonema -complex would result in two reciprocally monophyletic complexes.

Notes. The only known male in the N. orthonema -complex fits perfectly in the N. spio -group and is easily identified. In contrast, females had to be included in several keys and can only be identified by details of egg structure which are difficult to see.