A new genus and two new species (Gastropoda, Hydrobiidae) from Morocco

From 2014 to 2019 at more than 100 localities freshwater molluscs were collected along the basin of Moulouya River and Oriental Region of Morocco. These samples revealed two new hydrobiid species which are described here. One new species of Islamia and one species of a new genus. Photos of the holotypes are presented in addition to the penis morphology of the new genus and a map of the sampling area with the type localities.


Introduction
Only a few hydrobiid genera are known from Morocco, most of these also occur in Europe. These are Hydrobia W. Hartmann, 1821, Ecrobia Stimpson, 1865, Peringia Paladilhe, 1874, Heideella Backhuys & Boeters, 1974, Mercuria Boeters, 1971, and Pseudamnicola Paulucci 1878. If the genus Iglica A.J.Wagner, 1927 occurs in Morocco must be questioned. The description of Iglica seyadi Backhuys & Boeters, 1974 has been done by the shells only and the shell looks very different to other Iglica spp. from the Balkans. Recently Iglica soussensis Ghamizi & Boulal 2016 has been described from Morocco, unfortunately the authors overlooked the description of Sorholia Boeters & Falkner, 2009, described from the Pyrenees, to which this species possibly belongs. Also recently the genus Atebbania Ghamizi, Bodon & Giusti 1999 has been described from Tiznit, Morocco.
In 2017 Taybi AF & Mabrouki Y in Morocco, the shells and anatomy are different from Bullaregia, so it will be described here as a new genus. In addition a new species of Islamia has been found and is described below as new for science.

Material and methods
Sampling. Field surveys were conducted from 2014 to 2019, in which more than 100 localities were collected along the basin of Moulouya River and Oriental Region of Morocco. Most of these sampling sites were visited several times. Our goal was to document maximum macroinvertebrate biodiversity in the different microhabitats prospected at each sampling site. The samples of benthic fauna were collected by a kick net and clamps. The samples have been fixed in 75% ethanole.
The dissections and measurements of the genital organs and the shells were carried out using a stereo microscope (ZEISS); the photographs were made with a digital camera system (Leica R8). The type material is stored in the Zoological Museum of Hamburg (ZMH).

Study Area
Morocco is currently divided into 12 regions, including the Oriental Region (Fig. 1), which occupies almost all the eastern side of the country and covers an area of 90,127 km 2 (see Taybi et al. 2017 for details). The Oriental Region includes the wilaya of Oujda (Oujda-Angad prefecture) and the provinces of Berkane, Driouch, Figuig, Guercif, Jerada, Nador and Taourirt. The watershed of the Moulouya (Fig. 1)

Results
The first new species is a valvatoid hydrobiid snail, possibly a member of the genus Islamia, which also inhabits Northern Spain (Asturias and Catalania). Unfortunately only a few empty shells could be found that it was not possible to study the anatomy.
As hydrobiid species are characterized by the penis morphology in combination with the shell shape (Szarowska 2006), the second species which has been found could be assigned to a new genus.
The shell is valvatiform with a roundish-ovoid aperture and a sharp outer lip. Species of the genus occur in the Balkan Peninsula, Turkey (Radoman1983), Italy (Cossigniani 1995), France (Falkner et al. 2002) and Spain (Bank & Neubert 2018 Habitat: Tiffert is a rheocenous spring (flows directly on the ground) located at an altitude of 7 m, and flows into a large basin before joining the Moulouya River at about 50m. The banks are natural, with a dense tree-lined vegetation on the banks and weak sunlight. The grain size of the bottom consists of blocks, stones, pebbles and a lot of plant debris. Located in a rural environment, it is subjected to strong anthropic pressure: washing of linen, pumping of water for irrigation and domestic use.
Etymology: named after the sampling site.

Description:
The light corneous glossy shell is valvatoid, conical with a very short spire and a very prominent inflated body whorl. The 3.5 whorls are fast growing, the apex is blunt. The aperture is nearly circular, at the top attached to the shell wall over a short distance with a rounded angle.The umbilicus is wide, not covered by the last whorl. The shell is 0.8 mm high and 1.3 mm broad. Associated species: Aghbalia aghbalensis n. gen. n. sp. Distribution: only known from type locality.
Genus Aghbalia n. gen. Type species: Aghbalia aghbalensis n. gen. n. sp. Diagnosis: Characeristic is the reddish-brown shell with the aperture which border is sinuated from lateral view. In addition the penis has two penial appendices.
Habitat: located in the Oued Aghbal River basin at an altitude of 292 m, the Aghbal locality is a fully developed Rheocenous spring, water is routed through concrete pipes to a small retention basin before being redistributed again for domestic and agricultural purposes. Generally, in Eastern Morocco, Springs are highly influenced and subjected to a great anthropic pressure considering the scarcity of fresh water (Mabrouki et al., 2017b).
Etymology: named after the type locality.

Description:
The reddish brown shell is ovate with 3.5-4 slightly convex whorls which are separated by a weak suture. The aperture is ovate, tapered at the top. The peristome is sharp, from lateral view sinuated. The umbilicus is closed. The shell is 1.9 mm high and 0.9 mm broad. Male copulatory organ: The penis (part with the dark spot) has two large appendices. Differential diagnosis: The similar looking species from Tunisia, described as Bullaregia tunisiensis Khalloufi, Béjaoui & Delicado 2017, has a straight border of the aperture from lateral view. The penis is long and slim and has only one penial appendix.