Distribution of aquatic beetles from the east of Morocco ( Coleoptera , Polyphaga )

Distribution of aquatic beetles from the east of Morocco (Coleoptera, Polyphaga). We present old and new faunistic and distributional data on aquatic Polyphaga (Coleoptera) from the east of Morocco, comprising the Oriental Region and the basin of Moulouya River. A checklist of 91 species belonging to 27 genera and seven families is provided. Ochthebius quadrifossulatus (Hydraenidae) and Pomatinus substriatus (Dryopidae) are new records for the basin of Moulouya River, and Helophorus occidentalis, H. discrepans, H. flavipes, Hydrochus flavipes, Anacena globulus, Enochrus fuscipennis and Hydrobius fuscipes, all belonging to the family Hydrophilidae, and Limnebius furcatus, Ochthebius aeneus and O. merinidicus (all Hydreanidae) are new for the entire studied area of Eastern Morocco. We found a clear dominance of the Palearctic elements, mainly Mediterranean, with a high proportion of Ibero–Maghrebian endemisms. This chorotype pattern is similar to those observed for other macroinvertebrates orders in the same study area. Data published in GBIF (Doi: 10.15470/saajc8)


Introduction
The biodiversity crisis is one of the major challenges facing humanity today (Purvis and Hector, 2000).This massive erosion is due to the increasing acceleration of species' extinction rate due to anthropogenic activity, causing an irreversible loss of biological information with unpredictable consequences (Kerr and Currie, 1995;Rands et al., 2010).We live in an unprecedented era of biodiversity loss and biologists predict that tens of thousands of species and millions of populations will be extinct in the coming decades (Purvis and Hector, 2000;Barnosky et al., 2011).Biological diversity of continental aquatic ecosystems is generally higher than most other ecosystems (Darwall et al., 2008).As a result, the loss of biodiversity within inland waters would be much greater than in other ecosystems (Allan and Flecker, 1993;Ricciardi and Rasmussen, 1999).
Aquatic macroinvertebrates play a vital role in terms of biodiversity and ecosystem functioning, and consequently in the stability of ecosystems (Wallace and Webster, 1996).They also allow the diagnosis of alterations causes, the establishment of criteria for protection and restoration of interesting ecosystems and finally the integrated management of watersheds (Abellán et al., 2007).Thus, good knowledge of the species presence and distribution is necessary to protect biodiversity (Millán et al., 2014).In this framework, we carried out several studies regarding monitoring of aquatic ecosystems based on macroinvertebrate communities in Oriental Morocco and the basin of Moulouya River (Daoudi et al., 2017;Mabrouki et al., 2016bMabrouki et al., , 2017aMabrouki et al., , 2017c, in press;, in press;Taybi, 2016;Taybi et al., 2016bTaybi et al., , 2017bTaybi et al., , 2018a)), including aquatic Adephaga beetles (Taybi et al., 2017a).
Water beetles make up a large part of aquatic invertebrates (Jäch and Balke, 2008), so they are ideal candidates to be used as indicators of biodiversity of aquatic ecosystems, given their great specific and functional diversity, the great variety of habitats they are able to colonize and the general good taxonomic and faunistic knowledge (Bilton et al., 2006;Sánchez-Fernández et al., 2006).
With the aim of improving knowledge of the water beetles in the east of Morocco and completing previous studies (see Taybi et al., 2017a) on this group, we compiled a commented checklist of new and old records on the presence and distribution of the aquatic beetles belonging to the suborder Polyphaga) from Oriental Morocco and the Moulouya basin.

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., 2017a 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), which includes nearly 43,412 km 2 of eastern Morocco, covers much of the Oriental Region.With a length of 600 km, the Moulouya is the largest Moroccan river flowing into the Mediterranean.The main tributaries are the Oued Ansegmir, Oued Melloulou, Oued Za and Oued Msoun, all permanent.Other tributaries are intermittent (3-5 flashfloods on average per year) (Bensaad et al., 2017;Mabrouki et al., 2017c).

Sampling
In field surveys conducted from 2014 to 2017, more than 100 localities were collected along the basin of Moulouya River and Oriental Region of Morocco (see appendix for the complete list of localities).Most of these sampling sites were visited at least three 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 using a kick net, landing nets and clamps.The macroinvertebrates, including water beetles, were identified to species level, placed in accordingly labeled tubes with alcohol at 70 % or 96 %, and deposited in the collections of aquatic macroinvertebrates at the Laboratory of Water Sciences, Environment and Sustainable Development of the University Mohammed Premier from Oujda (Morocco), and the Department of Ecology and Hydrology, Faculty of Biology, University of Murcia (Spain).

Chorological study
The chorological categories proposed for the 91 species of Oriental Morocco and the Moulouya watershed were ranked according to La Greca (1964, 1975) and Vigna Taglianti et al. (1992) for the western Palearctic fauna.

Abbreviations
The new species for Moulouya basin are marked by #, and those for the entire area by *.

Results
A checklist of 91 species belonging to 27 genera and seven families is provided (appendix 1).It is also published in GBIF as a dataset (doi: 10.15470/saajc8).

Helophorus (Empleurus) porculus Bedel, 1881
Distribution: Atlanto-Mediterranean species.This is a mountain taxon in Morocco where it is known in the Middle Atlas and Anti Atlas (Benamar, 2015).In the Oriental region it was previously recorded at Oujda by Chavanon et al. (2004).
Distribution: West Mediterranean species.In Morocco it is known from some localities in the north (Benamar, 2015).In the Oriental region it was recorded from Debdou (Benamar, 2015).During the sampling period, the species was found in the Eastern Middle Atlas (fig.2).This species is not listed for Morocco in the catalogue of Hydrophiloidea from Paleartic region but for Algeria (Fikacek et al., 2015).Recently it has been recorded in the oriental part of the Rif Mountain (unpublished data).
Distribution: Euro-Maghrebian species.In Morocco it is known from some very scattered localities in the northern part (Benamar, 2015).In the Oriental region it was recorded from Charef River (Benamar, 2015).During the sampling period, the species was found in the Middle Eastern Atlas, corresponding to upstream of Melloulou River (fig.2).Despite this species having been recorded several times in Morocco, Fikacek et al. (2015) did not include it in any of the Maghrebian countries, so its presence in Morocco and the study area need confirmation.
Distribution: Turranic-Euro-Maghrebian species.In Morocco it was recorded in the Middle Mountains and the Anti Atlas (Angus, 1987).H. discrepans was found in the Upper Moulouya (fig.2).It is a new taxon for the studied area.

Helophorus (Rhopalhelophorus) fulgidicollis Motschulsky, 1860
Distribution: West Mediterranean species.In Morocco it is known from a few localities in the far north (Benamar, 2015).In the Oriental region it was recorded from the region of Nador (Bennas, 2002) and around Oujda (Chavanon et al., 2004).

Helophorus (Rhopalhelophorus) asturiensis Kuwert, 1885
Distribution: West Mediterranean species.In Morocco it is known from a few localities in the far north (Benamar, 2015).In the Oriental region it was recorded from Oujda (Chavanon et al., 2004).

Helophorus (Rhopalhelophorus) pici Guillebeau, 1893
Distribution: Maghrebian species.In Morocco it is known only from three localities: two refer to the Dades gorges in the region of Souss-Massa-Draa (Bouzidi, 1989) and one in the studied region around Oujda (Chavanon et al., 2004).We were unable to study material of this species, but Chavanon et al. (2004) refer that it was identified by Robert Angus, a specialist on this genus.
Distribution: Palearctic species.In Morocco it has a disperse presence in the northern part (Benamar, 2015).H. flavipes was found in the Upper Moulouya and in the Highlands (fig.2).It is a new taxon for the studied area.Mabrouki et al.
Distribution: Atlanto-Mediterranean species.In Morocco it is spread mainly in the north part (Benamar, 2015).H. flavipennis Küster, 1852 was found in the Upper Moulouya (fig.3).It is a new taxon for the studied area.Although this species is not mentioned for Morocco in Fikacek et al. (2015), it is a relatively common species in this country (Benamar, 2015); however, a deeper taxonomical study is needed to disentangle the possible existence of a complex of species within this species.
Distribution: West Mediterranean species.In Morocco it is scattered in the northern part (Benamar, 2015).In the Oriental region it was recorded from the Beni Snassen mountains (Chavanon et al., 2004).Our study significantly increases its previous range of distribution in the study area (fig.3).
Distribution: Holarctic species.In Morocco it is confined to the extreme north-west (Benamar, 2015).In the Oriental region it was recorded from Berkane (Benamar, 2015).During the sampling period, A. lutescens was found in the Upper Moulouya (fig.4).
Distribution: West-Palearctic species.Quite rare in Morocco, known only in a few localities scattered in the north (Benamar, 2015).This is a new species for the area studied, E. fuscipennis was found in the Upper Moulouya (fig.4).
Distribution: Holo-Mediterranean species.Widely distributed in Morocco (Benamar, 2015).On the other hand, this study greatly increases its range in the Oriental region and the catchment area of the Moulouya (fig.4).In Morocco it is known only from the Western Rif (Benamar, 2015) and from the Oriental region in Figuig (Chavanon et al., 2004).
Distribution: Atlanto-Mediterranean species.Widely distributed in the northern part of Morocco (Chavanon et al., 2004;Benamar, 2015).Our study significantly increases its range in the Oriental region and the Moulouya basin (fig.4).
Distribution: Holarctic species.In Morocco it is known from a few localities scattered in the north (Benamar, 2015).H. fuscipes was found in the Upper Moulouya corresponding to the Eastern Middle Atlas (fig.5).It is a new species for the study area
Distribution: Euro-Mediterranean species.Widely distributed in the northern part of Morocco (Chavanon et al.,2004;Benamar, 2015).Our study can significantly increase its range in the Oriental region and the catchment area of the Moulouya (fig.5).

Coelostoma (Coelostoma) hispanicum (Küster, 1848)
Material Distribution: West-Mediterranean species.Widely distributed in the northern part of Morocco (Benamar, 2015).Our study makes it possible to increase its range considerably in the Oriental region and the Moulouya basin (fig.5).
Distribution: Maghrebian species.Widely distributed in the northern part of Morocco and in the study area (Berrahou et al., 2001;Chavanon et al., 2004;Benamar, 2015).During the sampling period, H. rigua was found in the Upper Moulouya and in Oued Zeghzel (fig.6).

Hydraena (Phothydraena) cf. hernandoi Fresneda and Lagar, 1990
Material examined: Irhdis, 13.06.14, 1 female.Distribution: Ibero-Maghreb species.In Morocco it is scattered in the northern part (Benamar, 2015).It could be a new taxon for the Moulouya watershed, but it must be confirmed by the capture of a male.Only one female was found during the sampling period in the Upper Moulouya (fig.6).
Distribution: Atlanto-Mediterranean species.Known in Morocco of some scattered localities (Benamar, 2015).It is a new taxon for the study area.During the sampling period, the species was found along Anzegmir and Melloulou Rivers and later in Middle Moulouya (fig.6).

Ochthebius (Ochthebius) auropallens Fairmaire, 1879
Distribution: Holo-Mediterranean species.In Morocco it is known only from a few localities scattered in the northern half (Benamar, 2015).In the study area, it was recorded from Outat Al Haj and Zeghzel (Chavanon et al., 2004).
Distribution: Holo-Mediterranean species.In Morocco it is widely distributed in the northern part including the study area (Chavanon et al., 2004;Benamar, 2015).During the study period, O. mediterraneus was found in the south of the Oriental region around Figuig (fig.7).
Distribution: Ibero-Maghrebian species.In Morocco it is known from some localities, scattered in the northern part (Benamar, 2015).This is a new taxon for the study area.During the sampling period, O. merinidicus was found in Za and Melloulou Rivers, in addition to Upper Moulouya (fig.7).

Ochthebius (Ochthebius) nanus Stephens, 1829
Distribution: West-Euro-Maghrebian species.In Morocco it is scattered throughout the northern half (Benamar, 2015).In the Oriental region it was recorded from Oujda and Zeghzel (Chavanon et al., 2004).In Morocco it is known from a few localities in the north (Benamar, 2015).In the Oriental region it was recorded from Figuig (Benamar, 2015).

Ochthebius (Ochthebius) quadrifossulatus Waltl, 1835#
Material examined: Pont Gafait, 17.05.14, 1 male.Distribution: Ibero-Maghrebian species.In Morocco it is distributed in the north-west (Benamar, 2015).In the Oriental region it was reported from Figuig (Benamar, 2015).On the other hand, it is a new species for the basin of Moulouya River.During the sampling period, O. quadrifossulatus was found in the Za River (fig.8).

Ochthebius (Ochthebius) semisericeus complex
Distribution: West-Mediterranean species.In Morocco it is known only in the Oriental region, from where it was recorded from Lower Moulouya (Chavanon et al., 2004).This taxon needs a deep morphological study to confirm its taxonomical status.

Limnius intermedius Fairmaire, 1881
Distribution: Euro-Mediterranean species.In Morocco it is widely distributed in the northern part (Benamar, 2015).In the Oriental region it was recorded from Oujda and Lower Moulouya (Chavanon et al., 2004).
Distribution: Maghrebian species.Widely distributed in the northern half of Morocco, thus the area of our study (Chavanon et al., 2004;Benamar, 2015).It is the most abundant Elmidae in the Moulouya watershed and the Oriental region (fig.9).
Distribution: Atlanto-Mediterranean species.In Morocco it is known from few disperse ocalities (Benamar, 2015).In the Oriental region it was recorded from Tafoghalt (Chavanon et al., 2004).During the sampling period, O. troglodytes was found in the Upper Moulouya including Anzegmir River (fig.9).
Distribution: Afrotropical-Mediterranean species.Widely distributed in Morocco including in the studied area (Chavanon et al., 2004;Benamar, 2015).Our study significantly increases its distribution area in the basin of the Moulouya and the Oriental region (fig.3).
Distribution: Holo-Mediterranean species.In Morocco it is widely distributed in the northern part and thus in the study area (Chavanon et al., 2004;Benamar, 2015).Our study significantly increases its distribution range in the basin of the Moulouya and the Oriental region (fig.3).

Elodes marocanus Pic, 1939
Distribution: Moroccan endemic species, marocanus was before a variety of chobauti Abeille, 1894 and became a full species.In eastern Morocco, it was recorded from Guerraouaou (Chavanon et al., 2004).

Hydrocyphon australis Lindner, 1864
Material examined: Sources O. Bered, 01.06.14, 3 larvae; Aval Zeghzel, 28.04.16, 3 larvae.Distribution: West Mediterranean species.In eastern Morocco, it was recorded from Zeghzel (Chavanon et al., 2004) where it was found during the sampling period (fig.3).Only larvae were collected, so we need caught adults to confirm its presence in the study area.

Discussion
The ninety-one species of Polyphaga found in this study (including the two doubtful species) represent an important richness, proportionally comparable to the number of species found in other areas with similar environmental conditions (Sánchez-Fernández et al., 2004) and more deeply studied for this group of water beetles.Our study adds considerably to the previous knowledge about these insects in the study area, with two new records for the Moulouya basin and ten species for the entire area.This number of species reflects a high aquatic habitat heterogeneity in the study area, in a wide e variety of water bodies, from lotic with low conductivity waters, to very highly saline and lentic waters (Chavanon et al., 2004).Unfortunately, these habitats are currently not only endangered due to climate change, but also due to to the drying up of several streams, deforestation and urbanization by intensification of agriculture, infrastructure development, water pollution by fertilizers for agriculture, mosquito control and, especially, by wastewaters (Bensaad et al., 2017;Mabrouki et al., 2016aMabrouki et al., , 2017a;;Taybi et al., 2016a;Yahya et al., 2017).Indeed, many species recorded earlier in the Oriental region were not collected, a finding observed for other aquatic macroinvertebrates groups (Mabrouki et al., 2016b(Mabrouki et al., , 2017a;;Taybi et al., 2017aTaybi et al., , 2017b)), several species of which have decreased their regional range.
The species pool of aquatic Polyphagous beetles from Oriental Morocco and the watershed of the Moulouya can be subdivided into three main chorological categories (fig.10): first, the Mediterranean chorotypes, that are dominant and which constitute 64 % of the recorded species; second, the Palearctic chorotypes that constitute 25 %; and third, the Cosmopolitan chorotypes that constitue 11% and whose distribution extends beyond the Mediterranean either in India or in the Afrotropical region.Within the Mediterranean Polyphagan elements, there is a clear predominance of the endemic chorotype in the broadest sense (55 %), followed by the West-Mediterranean chorotype (27 %) and finally the Atlanto and Holomediterranean, each with 17 %.Despite being a Maghrebian country, the Ibero-Maghrebian endemics showed a similar richness value to that of the Maghrebian endemics.A similar pattern has been found in Polyphaga for all the Moroccan territory (Benamar, 2015).
The clear dominance of the Palearctic elements, typically Mediterranean, and the high rate of Ibero-Maghrebian endemism in the coleopterological population of the study area shows a strong similarity to the chorotypes found for other macroinvertebrates orders (Mabrouki et al., 2016b(Mabrouki et al., , 2017a;;Taybi et al., 2017aTaybi et al., , 2017bTaybi et al., , 2018b)).