Esolus pygmaeus (Müller, 1806)

Lamine, Smail, Lounaci, Abdelkader & Bennas, Nard, 2019, Biodiversity and chorology of aquatic beetles (Coleoptera: Elmidae and Hydraenidae) in Kabylia (central-north Algeria). New records and updates, Zootaxa 4700 (1), pp. 102-116 : 110

Esolus pygmaeus (Müller, 1806)

Material examined. BH: 9-V-2013 (12 exs.), S1: 9-V-2013 (25 exs.).

Chorotype. Europeo-Mediterranean.

In North Africa, E. pygmaeus is recorded from Morocco, Algeria, and Tunisia. In Algeria, the species is reported from the northern part of the country in Mazafran, and Chéllif (Blida) ( Arab 2004), and in the north-east from Ghar Rouban ( Oran) ( Berthélemy 1964). In Kabylia, the species is recorded from the Djurdjura massif ( Aït Mouloud 1988; Lounaci-Daoudi 1996; Lounaci 2005).

In this study, it was found extremely rarely in only middle-reach streams, with intermittent flow, located at altitudes between 160 m and 200 m. The two sites are impacted by domestic water pollution and sand and gravel extraction. In Spain, this taxon is considered relatively tolerant of organic pollution (Garcia-Críado & Fernández- Aláez 1995).

In Slovakia E. pygmaeus prefers hyporhithral to epipotamal reaches of streams and smaller rivers in lowlands and hills around 300m a.s.l. ( Čiampor & Zaťovičová 2004). In Czechia, the species is considered very rare and endangered ( Boukal et al., 2007). However, in Morocco, the species is widely distributed in the main areas of the country, where it inhabits headwaters, middle-reach streams, and is rarely found in lowlands, at altitudes between 10 m and 1820 m ( Bennas & Sáinz-Cantero 2007; Benamar 2015).