The fingernail clams (Bivalvia: Veneroida: Sphaeriidae) of Morocco: Diversity, distribution and conservation status.

Mohamed Ghamizi,Hassan Benaissa,Catharina Clewing,Hanane Rassam,Christian Albrecht

doi:10.3897/bdj.9.e73346

Abstract

BackgroundIn Morocco, many uncertainties surround the current diversity and distribution of the bivalve family Sphaeriidae. Such information, including taxonomy and conservation status, are vital for further studies to improve the knowledge of this family in Morocco and represents the first step towards the development of a national conservation plan for all freshwater bivalves.Between 2016 and 2019, several investigations were carried out to assess the diversity and distribution of Sphaeriidae in the different basins of Morocco, covering different types of habitat (lakes, springs, rivers and small ponds). The identification of specimens and their morpho-ecological features was based on morphological and morphometric analyses. The data on the general distribution of the collected species allowed the evaluation of their conservation status as well.The shell morphology and morphometric analyses revealed the existence of five species belonging to the genus Pisidium [P.casertanum (Poli, 1791), P. (cf.) personatum Malm, 1855, P.subtruncatum Malm, 1855, P.amnicum (O. F. Müller, 1774) and Pisidium sp.] and one species to the genus of Musculium [M.lacustre (O. F. Müller, 1774)]. Sphaeriidae were found in all Moroccan basins, except Bouregreg and Sakia El Hamra-Oued Eddahab Basins. The results showed that Sebou Basin was the species richest with the occurrence of the five species, while Loukkos and Sous-Massa Basins had the lowest-species richness with one species only. The conservation status of sphaeriids in Morocco was evaluated for the first time and resulted in P. (cf.) personatum and P.subtruncatum being proposed as Least Concern and Vulnerable, respectively, while the status of Regionally Extinct is suggested for both species P.amnicum and M.lacustre.New informationFirst evaluation of the diversity and species richness of the family Sphaeriidae in Morocco with an assignment of an updated conservation status of the recorded species.

Highlights

The North African region is globally identified as containing ecosystems with an important biodiversity (Cormier-Salem et al 2018)
Given the importance and the lack of information on the basic bio-ecological features of Sphaeriidae in Morocco, this study aims to: i) present a first evaluation of the diversity of Sphaeriidae in Morocco, including species richness and composition, using morphometric and geometric analysis, ii) assess the distribution pattern of Sphaeriidae in Moroccan freshwater basins and iii) assign a conservation status to the Moroccan species of Sphaeriidae
The results of the present study confirmed the existence of at least six sphaeriid species occurring in different basins in Morocco

Summary

Introduction

The North African region is globally identified as containing ecosystems with an important biodiversity (Cormier-Salem et al 2018). The family counts more than 220 species that often dominate benthic communities in aquatic ecosystems including rivers, streams, lakes and even ephemeral pools (Herrington 1962, Kuiper 1983, Sousa et al 2011, Burch 1975). They can be of high importance in the ecosystem such as their significance to the phosphorus cycle (Kasprzak 1986). In Morocco, many uncertainties surround the current diversity and distribution of the bivalve family Sphaeriidae. The conservation status of sphaeriids in Morocco was evaluated for the first time and resulted in P. (cf.) personatum and P. subtruncatum being proposed as Least Concern and Vulnerable, respectively, while the status of Regionally Extinct is suggested for both species P. amnicum and M. lacustre

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