Ommatoiulus alacygni, Nesrine Akkari & Henrik Enghoff, 2017

Nesrine Akkari & Henrik Enghoff, 2017, Revision of the genus Ommatoiulus Latzel, 1884 (Julida, Diplopoda) in Portugal, with description of six new species, European Journal of Taxonomy 295, pp. 1-42 : 3-6

Ommatoiulus alacygni sp. nov.

urn:lsid:zoobank.org:act:11FBA7C7-2310-48BC-A33E-D469C97BFD3E

Figs 1–3

Diagnosis

Most similar to O. denticulatus sp. nov. and O. staglae sp. nov., agreeing with these in having a very reduced mesomerite and a complex multi-branched solenomerite; differing from both in the shape of the solenomerite and the jagged coxa resembling, in posterior view, a swan wing.

Etymology

The species epithet is a composite Latin noun meaning “swan wing” and refers to the shape of the gonopod coxa.

Material examined

Holotype

PORTUGAL: 1 ♂, Faro District, Algarve, Ferragudo, 7 Mar. 1981, D. Kime leg. (ZMUC).

Paratype

PORTUGAL: 1 ♀, same data as holotype.

Description

MEASUREMENTS. Male: L = 35 mm, H = 3 mm, 45 PR+1 AR+Telson. Female: L = 45 mm, H = 4.2 mm, 46 PR + 2 AR +Telson.

COLOUR. Faded after 35 years in alcohol ( Fig. 1 ). Prozonites dark, greyish (perhaps originally deep brown); metazonites pale, almost whitish; dorsum with a thin black mid-dorsal line; legs pale brown to yellowish; head dark brown on the frontal part, paler towards the labral zone, mouthparts yellowish; preanal ring pale, anal valves blackish. Prozonites with oblique striae; metazonites with regular striation; suture complete, rectilinear but sometimes with a sinus at ozopore level. Anal valves with a marginal row of short setae, a submarginal row of longer ones, no setae (? broken) on disc. Subanal scale triangular, blunt and setose. Preanal ring with a protruding caudal projection bearing 2–3 setae on tip, no hyaline process (?broken).

GONOPODS (Figs 2–3). Promerite (P) stout, basally parallel-sided in posterior view, twice as long as broad with a rounded lateral margin, distally gradually narrowing and ending in a narrow apical tip; mesal ridge (Mr) fairly broad, ending in a blunt process at mid-length of the promerite; posterior surface with a small concavity near the mesal ridge (lodging the mesomerite); rudimentary telopodite (T) small and located proximally near Mr ( Fig. 3 A). Posterior gonopod ( Figs 2 B–C, 3B–C): Mesomerite (Ms) reduced and very simple, less than half as long as the promerite; solenomerite (S) large, with an anterior long process (Sa) narrowing distad, apically tapering and bent posteriad, subapically bearing a triangular median hyaline lamella (Hl); seminal groove (g) running posteriorly from the fovea (F) located at the base of the solenomerite along a posterior acuminate process (Sp) and opening in 'og'; the solenomerite shows another thin and long process pointing laterad (Sl). Paracoxite (Px) large, twisted antero-laterad and extending beyond the rest of processes; distally abruptly expanding in a rounded bulge ( Fig. 2 C, E) then apically narrowing in a curved thin apex pointing anteriad; coxa (Cx) very prominent, angular and characterised by the presence of a jagged margin with three protruding blunt processes, in lateral view reminding of the wing of a swan ( Figs 2 C, 3C ).

Distribution

South Portugal, Algarve, Ferragudo.

Figures

Fig. 1. Ommatoiulus alacygni sp. nov. Paratype ♀. habitus, lateral view.

Fig. 2. Ommatoiulus alacygni sp. nov. Holotype ♂, gonopods. A. Right promerite, posterior view. B. Right posterior gonopod, mesal view. Line marking the broken paracoxite. C. Left gonopod, lateral view. D. Left gonopod, meso-posterior gonopod. E. Left gonopod, antero-lateral view.

Fig. 3. Ommatoiulus alacygni sp. nov. Holotype ♂, gonopods. A. Right promerite, posterior view. B. Left gonopod, mesal view. C. Left gonopod, posterior view.