Mercuria atlasica, Mabrouki & Glöer & Taybi, 2021

Mabrouki, Youness, Glöer, Peter & Taybi, Abdelkhaleq Fouzi, 2021, Two new species of the genera Islamia and Mercuria (Gastropoda, Hydrobiidae) from Morocco, Ecologica Montenegrina 39, pp. 76-80 : 79

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.

Figures

Figure 1. The sampling site and habitat of Islamia karawiyiensis n. sp and Mercuria atlasica n. sp.

Figures 2-4. 2: shell of Islamia karawiyiensis n. sp., 3: shell of Mercuria atlasica n. sp., 4: male copulatory organ. Abbreviations: e: eye, p: penis, pl: penial lap, s: snout.