Menzella timedrinensis, Mabrouki & Glöer & Taybi, 2023

Mabrouki, Y., Glöer, P. & Taybi, A. F., 2023, The valvatiform hydrobiids (Gastropoda: Truncatelloidea: Hydrobiidae) of Morocco with description of a new genus and species, Zoosystematica Rossica (China) 32 (1), pp. 116-123 : 118-119

Menzella timedrinensis sp. nov.

( Figs 1G, 2–5)

Holotype. Male (adult specimen); Morocco, Middle Atlas , Fez-Meknes Region , Sefrou Province , Ain Timedrine spring nr. El Menzel town, 33°44′52.0273″N, 04°32′52.2110″W, 24 May 2022 ( ZMH 141471 ). Kept in ethanol.

Paratypes. Same locality, 50 specimens ( ZMH 141472 ), 6 specimens (Y. Mabrouki collection). Kept in ethanol .

Description. Shell valvatoid, globular, with 3.5 slightly convex whorls separated by a clear suture. Body whorls prominent. Aperture nearly circular, with sharp peristome. Umbilicus wide and deep. In some specimens, aperture shifted to left ( Fig. 3A). In living specimens, mantle grey-black with white border, visible under translucent shell. Pigmentation of soft body variable. Tentacles long and broad (longer than snout), blackish at upper side and light at distal end. Snout wide, grey, with strong distal lobes. Eye spots well visible. Penis hook-shaped, with black spot in middle part, attached behind right eye. Female genitalia unknown.

Dimensions. Holotype: shell height 1.22 mm, diameter 1.28 mm. Paratypes: shell height 1.11– 1.54 mm, diameter 1.14–1.30 mm. Shell measurements of ten measured paratypes are summarised in Table 1. The images of measured shells are given in Fig. 5.

Etymology. The species was named after the type locality, Ain Timedrine spring.

Habitat. The type locality is the Ain Timedrine spring in a rural environment in the Middle Atlas, at 671 m above sea level ( Fig. 6). This karstic spring flows into the Sebou River and is characterised by a significant flow. The banks are natural, with sparse tree-lined vegetation. The sediments consist of stones, pebbles and a lot of plant debris. The entire site is subject to strong anthropogenic pressure, especially from agricultural and tourist activities during the dry season. Together with Sebou and Ouamender springs, Ain Timedrine plays an important role in stabilising

Mabrouki et al. The valvatiform hydrobiids of Morocco the flow of the Sebou River. These springs ensure the sustainability of the regime of the upper reaches of the Sebou River ( Akdim et al., 2012).