Mercuria atlasica n. sp.

Fig. 3-4

https://zoobank.org/ urn:lsid:zoobank.org:act: 9A47A682-2827-41FC-83D4-4D6194ECBAFB

Material examined: Holotype: shell height 2.95 mm, width 2.0 mm (ZMH 140823). Paratypes: (1) Fes 27/10/20, 10 paratypes (ZMH 140824), (2) Aouinat El Hajjaj 27/10/20, 10 paratypes coll Glöer, 31 paratypes ZMH 140825.

Locus typicus: Morocco, Aouinat El Hajjaj, Fez prefecture, 27/10/20, 34°01'36.7"N 4°58'06.9"W.

Description: The dark yellowish conical shell has 5.5 fast growing, slightly convex whorls with a deep suture (Figure 3). The body whorl is prominent. The ovate aperture is somewhat oblique, narrowed at the top with a rounded angle. The peristome is sharp, the umbilicus is closed. The shell is 2.8-3.0 mm high and 1.9-2.0 mm broad.

Male copulatory organ: The greyish penis is long, broad and tapered at the tip (Figure 4). The penial lobe is long and broad, whitish and rounded at the distal end.

Discussion: The new species can be distinguished from its congeners in Morocco by its penis almost equal in length with the unpigmented penial appendix. M. tingitana Glöer, Boeters & Walther, 2015 has black short and triangular penis, M. targouasensis Glöer, Boeters & Walther, 2015 has gradually tapering penis and slightly pigmented penial appendix, shorter than penis and M. tensiftensis Boulaassafer, Ghamizi & Delicado, 2018 has a gradually tapering dark pigmented penis with dark pigmented penial appendix. While M. bakeri Glöer, Boeters & Walther, 2015 has a long strap- like penis and M. midarensis Boulaassafer, Ghamizi & Delicado, 2018 has gradually tapering to strap-like penis and similarly pigmented penial appendix. All other Mercuria spp. known from Morocco occur in coastal regions.

Etymology: Named after the Atlas Mountains.

Habitat: This species seems rheophilous, preferring moderate to fast-flowing, well-oxygenized springs and streams (Figure 1), usually on solid substrate and stony bottoms but it can be found among aquatic vegetation.