Although Mercuria genus has received considerable attention in Morocco in terms of species discoveries, new species continue to be found in the country. The aim of this paper is to describe two new species of Mercuria found recently in northeastern Morocco

Glöer, Peter

Mabrouki, Youness

Taybi, Abdelkhaleq Fouzi

English

Hrčak - Portal of scientific journals of Croatia

NAT. CROAT. VOL. 31 No 1 63-69 ZAGREB July 31, 2022original scientific paper / izvorni znanstveni radDOI 10.20302/NC.2022.31.5TWO NEW SPECIES OF MERCURIA BOETERS, 1971 FROM MOROCCO (GASTROPODA, HYDROBIIDAE)Abdelkhaleq Fouzi Taybi1, Peter Glöer2, & Youness Mabrouki31Université Mohammed Premier, Faculté Pluridisciplinaire de Nador, Équipe de Recherche en Biologie et Biotechnologie Appliquées. Morocco  (E-mail: taybiaf@gmail.com, http://orcid.org/0000-0001-9652-5407)2Schulstr. 3, D-25491 Hetlingen, Germany  (E-mail: gloeer@malaco.de, https://orcid.org/0000-0001-6995-3641)3Université Sidi Mohamed Ben Abdellah, Faculté des Sciences de Dhar El Mehraz, Laboratoire de Biotechnologie, Conservation et Valorisation des Ressources Naturelles, Fes, Morocco  (E-mail: younes_mab@hotmail.fr, https://orcid.org/0000-0002-7336-8717)Taybi, A. F., Glöer, P. & Mabrouki, Y.: Two new species of Mercuria Boeters, 1971 from Morocco (Gastropoda, Hydrobiidae). Nat. Croat., Vol. 31, No. 1, 63-69, Zagreb, 2022.Although Mercuria genus has received considerable attention in Morocco in terms of species dis-coveries, new species continue to be found in the country. The aim of this paper is to describe two new species of Mercuria found recently in northeastern Morocco.Key words: Mercuria, Gastropoda, Morocco, new speciesTaybi, A. F., Glöer, P. & Mabrouki, Y.: Dvije nove vrste roda Mercuria Boeters, 1971 iz Maroka (Gastropoda, Hydrobiidae). Nat. Croat., Vol. 31, No. 1, 63-69, Zagreb, 2022.Iako je rod Mercuria u Maroku prilično dobro istražen, još uvijek se u zemlji otrkivaju nove vrste. Cilj rada je opisati dvije nove vrste roda Mercuria, nedavno pronađene u sjeveroistočnom Maroku.Key words: Mercuria, Gastropoda, Maroko, nova vrstaINTRODUCTIONMorocco is located in the Mediterranean basin hotspot, one of Earth’s biologically richest and most endangered ecoregions. It houses the second greatest concentration of continental biodiversity in the Mediterranean basin with species diversity compri-sing more than 31,000 species, about 11 percent of which are endemic (USAID, 2008). This high rate of endemism is particularly observed in the freshwater biodiversity of the northern part of the country, due to its many geographical barriers, such as the Rif and Atlas Mountains, and the Moulouya River basin (Mabrouki et al., 2019a, b; Marrone et al., 2020; Taybi et al., 2020). Morocco also has the most extensive river system within the northern African region, where a diversified molluscan fauna appears to live even in the aquifers in the karstic underground (Van Damme, 1984). The family Hydrobiidae Stimpson, 1865 is one of the largest families within the Truncatelloidea superfamily; it has a cosmopolitan distribution and is made up of small to minute species that inhabit permanent aquatic ecosystems. It includes a number of genera in Moroccan territory, among those, the genus Mercuria Boeters, 1971, which has a western Palearctic freshwater snail distribution. Species of this genus also occur 64 Taybi, A. F. et al.: Two new species of Mercuria Boeters, 1971 from Moroccoin the western Mediterranean region, from south-eastern France to North Africa, and they are also widely distributed in the Atlantic coastal regions from Ireland, to Moro-cco (Glöer et al., 2010; Glöer 2019).Previously, the genus Mercuria was represented by eight species in Morocco: M. globulina (Letourneux & Bourguignat 1887); M. atlasica Mabrouki, Glöer & Taybi 2021; M. bakeri Glöer, Boeters & Walther, 2015; M. tingitana Glöer, Boeters & Walther, 2015; M. targouasensis Glöer, Boeters & Walther, 2015; M. midarensis Boulaassafer, Ghamizi & Delicado, 2018; M. gauthieri Glöer, Bouzid & Boeters, 2010; M. tensiftensis Boulaa-ssafer, Ghamizi & Delicado, 2018. New investigations conducted recently through the eastern region of Morocco revealed two new species of the genus Mercuria. The aim of this paper is to describe these new species.MATERIAL AND METHODS Field surveys were conducted from 2014 (and are still ongoing) through the northern part of the country, including in its great natural barriers such as the Moulouya River basin and the Middle Atlas massif. Most of these sampling sites were visited several times. Our goal was to document maximum macroinvertebrate biodiversity in the different microhabitats investigated at each sampling site. The samples of benthic fauna were collected by a kick net and clamps. The samples have been fixed in 75% ethanol. The dissections and measurements of the genital organs and the shells were carried out using a stereo microscope (Leica M205C) with a digital camera (Leica DMC5400). The type material is stored in the Zoological Museum of Hamburg (ZMH).RESULTSGenus Mercuria Boeters, 1971Type species: Cyclostoma simile Draparnaud, 1805.The shell is whitish, especially in the region of the umbilicus. The penis possesses a large and flat triangular appendix.Identification key for Mercuria species of Morocco –  Shell spherical, short spire 0.2–0.3 of shell height, shell height 2.4–3.0 mm  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  M. globulina.–  Shell conical with 5.5 fast growing, slightly convex whorls with a deep suture. Shell 2.8–3.0 mm high and 1.9–2.0 mm broad. Penis broad and tapered at the tip, almost equal in length with the unpigmented penial appendix . . . .  M. atlasica.–  Shell conical with 5.5 slightly convex whorls with a deep suture. Shell height 3.0–3.5 mm, width 2.2–2.3 mm. Penis like a long strap, pigmented and lying above the penial appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  M. bakeri.–  Shell conical, the 5.5 whorls are slightly convex with a shallow suture. Shell height 3.5–3.8 mm, diameter 2.4–2.5 mm. Penis as long as penial appendix, with black short and triangular penis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  M. tingitana.–  Shell conical with 4.5-5 slightly convex whorls with a deep suture, the shell is 2.98–3.79 mm high and 2.5–2.6 mm broad. H: D = 1.2-1.3. The penis long and slen-Nat. Croat. Vol. 31(1), 2022 65der, widened at the basis and tapered at the distal end. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Mercuria nadorensis sp. nov.–  Shell short-conical, The 5.5 whorls are slightly convex with a deep suture. Shell height 3.1–4.0 mm, diameter 2.1–2.9 mm. It has gradually tapering penis and sli-ghtly pigmented penial appendix, shorter than penis . . . . . . .  M. targouasensis.–  Shell ovate-conic, whorls 4–5, height 3–4.7 mm, H: D = 1.4. It has gradually tapering to strap-like penis and similarly pigmented penial appendix . . . .  M. midarensis.–  Shell solid and conical with 4.5–5.1 slightly rounded whorls with a clear suture, shell height 3.5–4.7 mm, shell width 2.5–3.1 mm. The penis is thin, almost as long as penial appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  M. gauthieri.–  Shell ovate-conic, whorls 4–5, height 3–5mm. With a gradually tapering dark pi-gmented penis with dark pigmented penial appendix . . . . . . . . .  M. tensiftensis. –  Shell conical with 4.5–5 slightly convex whorls with a deep suture. The shell is 5.4 mm high and 3.6–3.8 mm broad, H: D = 1.5–1.6. The penis is long and slender with a broad and large penial lobe . . . . . . . . . . . . . . . . . . . . . . . . . . .  M. halouii sp. nov.Mercuria nadorensis sp. nov. (Figs. 1-8)Type material. Holotype. ZMH 140905, urn:lsid:zoobank.org:act:F887640D-DF51-4E6B-AA11-D58AB5646E60, shell height 2.98 mm, width 2.5 mm, 5 Paratypes: ZMH 140906, 5 paratypes coll. Glöer.Description. The conical shell has 4.5-5 slightly convex whorls with a deep suture. The aperture is ovate, with a rounded angle at the top. The peristome is sharp, somew-hat thickened at the inner lip. The umbilicus is slit like. The shell is whitish in the re-Figs. 1–8. Mercuria nadorensis sp. nov. 1: Holotype, 2-5: paratypes, 2-3 preserved and photographed under ethanol, 4-5: dried shells, 6: operculum,7: bursa copulatrix, 8: penis in situ. Abbreviations: bc = bursa copulatrix, p = penis, pl = penial lobe, ovl = oviductl loop, t = tentacle.66 Taybi, A. F. et al.: Two new species of Mercuria Boeters, 1971 from Moroccogion of the columella (cleaned shells). The ratio of shell height to width = 1.2-1.3. The shell is 2.98-3.79 mm high and 2.5-2.6 mm broad. The translucent operculum is paucis-piral with an excentric nucleus.Anatomy. The penis is long and slender with a broad basis and a large penial lobe, as is characteristic for Mercuria. The basis of the penis and the penial lobe are pigmen-ted. The female genitalia include a large, elongate ovate bursa copulatrix and a small receptaculum seminis.Differential diagnosis. The new species can be distinguished from its congeners in Morocco by its relatively long and slender penis, slightly pigmented, widened at the basis and tapered at the distal end. It can be confused with M. midarensis H: D = 1.4, the latter has larger shells (shell height 3–4.7 mm and shell width 2-3 mm broad), and larger penial appendix, wider at the distal end.Type locality. Source Oulad Bouazza, Nador, 12/04/2021, 35°02'51.0"N 3°06'55.0"W.Habitat. The species was sampled from an irrigation canal in the Bouareg valley, near the village of Taourirt Bousetta, probably supplied by water from wells located on private property. As a general rule in this area, Hydrobiidae molluscs are confined to wells and springs at the foot of mountain chains and the low-altitude plains.Distribution. Morocco; only known from type locality.Etymology. The species was named after Nador province where the species was found.Mercuria halouii sp. nov. (Figs. 9-11)Type material. Holotype: ZMH 140907, urn:lsid:zoobank.org:act:25477922-67E3-40C6-8E95-C637C0FF2E26, shell height 5.4 mm, width 3.6 mm, 1 Paratypes: ZMH 140908.Description: The conical shell has 4.5-5 slightly convex whorls with a deep suture. The aperture is ovate, somewhat oblique. The peristome is sharp, slightly thickened at the inner lip. The umbilicus is slit-like. The shell is whitish in the region of the columella (cleaned shells). The ratio of shell height to width = 1.5-1.6. The shell is 5.4 mm high and 3.6-3.8 mm broad.Figs. 9–11. Mercuria halouii sp. nov. 9: Holotype, 10: paratype, 11: penis in situ. Abbreviations: p = penis, pl = penial lobe (in alcohol).Nat. Croat. Vol. 31(1), 2022 67Anatomy: The penis is long and slender with a broad and large penial lobe. The basis of the penis and the penial lobe are pigmented. Differential Diagnosis. This new species can be confused with M. nadorensis n.sp. However, M. nadorensis sp. nov. is much smaller and more globular (H:D = 1.2-1.3) than M. halouii (H :D = 1.5-1.6).Type locality: Bouareg, Nador province, 10/07/2021, 35°04'44.0"N 2°55'42.2"W.Habitat. The type locality is a spring located near the village of Oulad Bouazza which is 8 km away from the town of Al Aroui, at an altitude of 1075 m. The spring was arranged as a well with a depth of 6 m and a diameter of 5 m. The vegetation is sparse and the area is sunny. This feature was also documented for other Mercuria species in the eastern region of Morocco (e.g. M. globulina and M. bakeri).Distribution: Morocco; only known from type locality.Etymology. The species is named in honour of Professor Benyounes Haloui (Moha-med Premier University of Oujda), in recognition of the many years of teaching gene-rations at the Faculty of Sciences of Oujda and for scientific works related to the natu-ral ecosystems of Morocco.DISCUSSIONMercuria nadorensis sp. nov. and Mercuria halouii sp. nov. can be distinguished from their Moroccan congeners by penis morphology in combination with the shell chara-cters. Our findings raise the known biodiversity of the Mercuria genus in Morocco to ten species (Mabrouki et al., 2021a). Mercuria midarensis is distributed mostly in nort-Fig. 12. Distribution of Mercuria spp in Morocco.68 Taybi, A. F. et al.: Two new species of Mercuria Boeters, 1971 from Moroccoheastern Morocco, M. tensiftensis can be found in proximal localities of the Tensift River basin in northwestern Morocco (Boulaasafer et al., 2018). Mercuria atlasica can be found in the edge of the Middle Atlas in the Fez region, M. tingitana seems restricted to its type locality in the Tingitane Peninsula, M. bakeri is restricted to the northern part of the country, M. targouasensis can be found in coastal streams in south-western Moroc-co and in a spring-fed habitat in the Middle Atlas. While M. nadorensis sp. nov., M. halouii sp. nov., M. globulina and M. gauthieri are restricted to the oriental region of Morocco, the latter two can also be found in northwest Algeria (Gloër et al., 2010). The oriental region of Morocco has the highest number of Mercuria species, especia-lly in the eastern Rif and the Lower Moulouya River basin (Fig. 12), this number of species being linked to the high variability and heterogeneity of biotopes of the studied area, but also to extensive investigations. Given the number of new species and gene-ra discovered during the last decade in this country (Glöer et al., 2015; Glöer et al., 2020a, b; Ghamizi, 2020; Mabrouki et al., 2021b; Mabrouki et al., 2022; Taybi et al., 2021), the discoveries of new hydrobiid snails or other molluscan taxa known to occur in Morocco will certainly increase with further studies and investigations.AcknowledgmentsOur thanks go to the students: Mennani Mounia and Oulaabdou Soumia who hel-ped collect the biological material. We also thank the editor and reviewers, whose helpful comments improved the present paper.Received January 16, 2022REFERENCESBoulaassafer, K., Ghamizi, M. & Delicado, D., 2018: The genus Mercuria Boeters, 1971 in Morocco: first molecular phylogeny of the genus and description of two new species (Caenogastropoda, Trunca-telloidea, Hydrobiidae). ZooKeys, 782, 95–128. https://doi.org/10.3897/zookeys.782.26797Ghamizi, M., 2020: New stygobiont genus and new species (Gastropoda, Hydrobiidae) from the Rif (Morocco). Ecologica Montenegrina, 31, 50–56. Glöer, P., 2019: The freshwater gastropods of the West Palaearctic Volume I Fresh- and brackish waters except spring and subterranean snails. Identification Key, Anatomy, Ecology, Distribution. Hetlingen. Germany. 399 pp.Glöer, P., Boeters, H.D. & Walther, F., 2015: Species of the genus Mercuria Boeters, 1971 (Caenogastro-poda: Truncatelloidea: Hydrobiidae) from the European Mediterranean region, Morocco and Made-ira, with descriptions of new species. Folia Malacologica, 23(4), 279–291.Glöer, P., Bouzid, S. & Boeters, H.D, 2010: Revision of the genera Pseudamnicola Paulucci 1878 and Mer-curia Boeters 1971 from Algeria with particular emphasis on museum collections (Gastropoda: Pro-sobranchia: Hydrobiidae). Archiv für Molluskenkunde, 139 (1), 1–22. Glöer, P., Mabrouki, Y. & Taybi, A.F., 2020a: A new genus and two new species (Gastropoda, Hydrobii-dae) from Morocco. Ecologica Montenegrina, 28, 1–6. https://doi.org/10.37828/em.2020.28.1 Glöer, P., Mabrouki, Y. & Taybi, A.F. 2020b. Two new valvatoid genera (Gastropoda, Hydrobiidae) from Morocco. Ecologica Montenegrina, 30, 124–128. https://doi.org/10.37828/em.2020.30.12Mabrouki, Y., Taybi, A.F., El Alami, M. & Berrahou, A., 2019a: Biotypology of stream macroinvertebra-tes from North African and semi-arid catchment: Oued Za (Morocco). Knowledge and Management of Aquatic Ecosystems, 420, 17. DOI: 10.1051/kmae/2019009.Mabrouki, Y., Ben Ahmed, R., Taybi, A.F. & Rueda, J., 2019b: Annotated checklist of the leech (Annelida: Hirudinida) species of the Moulouya river basin, Morocco with several new distribution records and an historical overview. African Zoology. 54(4), 199–214. DOI: 10.1080/15627020.2019.1671218.Nat. Croat. Vol. 31(1), 2022 69Mabrouki, Y., Taybi, A.F. & Glöer, P., 2021a: Further records of freshwater Gastropods (Mollusca: Hy-drobiidae, Lymnaeidae, Planorbidae) from Morocco. Bonn Zoological Bulletin 70(2), 273–279. DOI: 10.20363/BZB-2021.70.2.273 Mabrouki, Y., Taybi, A.F. & Glöer, P., 2021b: Two new species of the genera Islamia and Mercuria (Gas-tropoda, Hydrobiidae) from Morocco. Ecologica Montenegrina 39, 76-80. DOI: 10.37828/em.2021.39.8.Mabrouki, Y., Taybi, A.F. & Glöer, P., 2022: Idrisiella bourkaizensis n. gen. sp. nov. a new valvatoid snail (Gastropoda, Hydrobiidae) from Morocco. Invertebrates Zoology 19(1), 18–23.Marrone, F., Vecchioni, L., Deidun, A., Mabrouki, Y., Arab, A. & Arculeo, M., 2020: DNA taxonomy reveals an overlooked diversity hotspot for freshwater crabs in Northern Africa (Decapoda, Potami-dae). Zoologica Scripta 49(16). DOI: 10.1111/zsc.12415.Taybi, A.F., Mabrouki, Y., Berrahou, A., Dakki, A. & Millán, A., 2020: Longitudinal distribution of macroinvertebrate in a very wet North African basin: Oued Melloulou (Morocco). International jour-nal of Limnology 56(17), 1–11, Doi: 10.1051/limn/2020016.Taybi, A.F., Glöer, P. & Mabrouki, Y., 2021: Description of a new valvatoid Pikasia smenensis n. gen. sp. nov. (Gastropoda, Hydrobiidae) from Morocco. Animal Biodiversity and Conservation 44(2), 317–320. USAID, 2008: United States Agency for International Development/Morocco under Prosperity, Liveliho-ods and Conserving Ecosystems (PLACE) Indefinite Quantity Contract number EPP-I-03-06-00010-00, Task Order #03 awarded 02 September 2008, entitled Morocco Biodiversity and Tropical Forestry Assessment (“Morocco 118/119 Assessment”). 114pp.Van Damme, D., 1984: The freshwater mollusca of northern Africa: Distribution, Biogeography and Pa-laeoecology. In: H. J. Dumont (ed.). Developments in hydrobiology, 25. W. Junk Publishers. Dordre-cht. 176 pp.

Two new species of Mercuria Boeters, 1971 from Morocco (Gastropoda, Hydrobiidae)

Abstract

Similar works

Full text

Available Versions

Hrčak - Portal of scientific journals of Croatia