Research Article |
Corresponding author: Mokhtar Benlasri ( benlasri@gmail.com ) Academic editor: Jean-Luc Gattolliat
© 2023 Mokhtar Benlasri, Nils Kaczmarek, Majida El Alami, Mohamed Ghamizi, Elisabeth Berger.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Benlasri M, Kaczmarek N, El Alami M, Ghamizi M, Berger E (2023) Inventory and pattern of distribution of mayflies (Insecta, Ephemeroptera) in the Draa river basin, southern Morocco. Alpine Entomology 7: 13-20. https://doi.org/10.3897/alpento.7.96436
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The Draa river basin is located south of the High Atlas Mountain rangee in Morocco. The Ephemeroptera (mayflies) fauna of its three sub-basins: the High, Middle, and Lower Draa are poorly known. This study contributes to the knowledge of Ephemeroptera and its distribution in relation to environmental parameters in this area. The larvae of Ephemeropteran species were collected during six field campaigns in 17 sites using a Surber sampler. A total of thirteen species belonging to ten genera and five families were identified. among which seven taxa were recorded for the first time in the southern Atlas area: Baetis maurus, Baetis rhodani, Cheleocloeon dimorphicum, Cloeon simile, Procloeon stagnicola, Labiobaetis neglectus and Oligoneuriopsis skhounate. The limits of distribution of most species can be explained by the increase in water temperature and electrical conductivity especially at lower altitudes.
Bioindicators, biodiversity, Draa watershed, High Atlas, mayflies, Morocco
Mayflies (order Ephemeroptera) have a worldwide distribution. being absent only in Antarctica and some remote oceanic islands (
The development cycle of mayflies depends essentially on water. The larvae. after hatching from the egg undergo, a series of molts during their growth (
Since the twentieth and early twenty-first centuries, many mayfly-related studies have been carried out in Algeria (
Despite all those studies concerning Morocco, the Draa’s Ephemeroptera remain still almost unknown. The last study of a small part of this basin dates back to 1989 (
The objectives of this study are to update the list of Ephemeroptera by covering a large study area including the Upper, the Middle and a part of the Lower Draa. For this purpose, we have established the list of Ephemeroptera colonizing this basin and complete the inventory of Ephemeroptera for Morocco by adding different streams of the hydrographic network south of the High Atlas. Furthermore, we studied the environmental factors that shape the distribution of Ephemeroptera in the Draa basin, we also aim to locate in the study area the regions that have a high Mayfly diversity.
The geography of Morocco is characterized by the presence of four mountain ranges: the Rif in the north and the Atlas in the center, which is divided into three range: the High Atlas, the Middle Atlas and the Anti Atlas). The Draa basin, subject of this study is located in the south of the High Atlas that covers the reliefs of the southern part of the High Atlas until the south of the city of Zagora and extends to the Atlantic Ocean in the West (Fig.
The Draa basin covers an area of 115 000 km2 (
The sub-basin of the Middle Draa covers the area downstream of the El Mansour Eddahbi dam to the south of Zagora and extends to Mhamid El Ghizlane. It includes the main watercourse of Draa, which is dry during a large part of the year and whose water flow depends essentially on water releases from the dam.
The sub-basin of the Lower Draa, extends from the area of Mhamid El Ghizlane to the mouth of the Draa river in the Atlantic Ocean.
Seventeen sites were selected in the Draa basin (Table
Basin | Site | Name | River | GPS Coordinates | Altitude (m.s.l.) | Sampling dates | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
Jun 19 | Fe 20 | Oct 20 | Ap 21 | May 21 | Oct 21 | ||||||
UD | St1 | Ounilla upstream | Ounilla | 31°15.71’N, 7°9.24’W | 1724 | X | X | X | X | X | |
UD | St2 | Ounilla middlestream | Ounilla | 31°8.80’N, 7°8.43’W | 1425 | X | X | X | X | X | |
UD | St3 | El mellah | Oued El maleh | 31°0.69’N, 7°6.01’W | 1228 | X | X | X | X | X | |
UD | St4 | Iriri | Iriri | 30°56.27’N, 7°12.60’W | 1261 | X | X | X | X | X | |
UD | St5 | Ait douchene | Fint (up stream) | 30°39.46’N, 7°05.56’W | 1336 | X | X | X | X | X | |
UD | St6 | Tarmigt | Fint | 30°51.91’N, 6°50.79’W | 1114 | X | X | X | X | X | X |
UD | St7 | Dades upstream | Dades | 31°35.61’N, 5°52.36’W | 1814 | X | X | X | |||
UD | St8 | Gorges de Dades | Dades | 31°33.37’N, 5°54.51’W | 1753 | X | X | X | X | X | |
UD | St9 | Middle Dades | Dades | 31°30.28’N, 5°56.72’W | 1656 | X | X | X | X | ||
UD | St10 | Dades downstream | Dades | 31°0.72’N, 6°29.61’W | 1190 | X | X | X | X | ||
UD | St11 | Mgoune upstream | Mgoune | 31°21.83’N, 6°10.27’W | 1545 | X | X | X | X | ||
UD | St12 | Mgoune downstream | Mgoune | 31°20.07’N, 6°10.82’W | 1508 | X | X | X | X | ||
MD | St13 | Tamnougalt | Draa | 30°40.40’N, 6°24.36’W | 919 | X | X | X | X | ||
LD | St14 | Akka nait sidi 1 (left) | Tissint | 29°54.57’N, 7°19.87’W | 584 | X | X | X | X | X | |
LD | St15 | Akka nait sidi 2 (right) | Tributary tissint | 29°54.71’N, 7°19.87’W | 582 | X | X | X | X | X | |
LD | St16 | Tissint near the road | Tissint | 29°49.54’N, 7°11.92’W | 486 | X | X | X | X | X | X |
LD | St17 | Mghimima | Zguid | 29°46.81’N, 7°10.10’W | 483 | X | X | X | X | X | X |
The sampling was conducted from June 2019 to October 2021. The first sample in June 2019 was done following a qualitative protocol to know which site we could use in the subsequent samplings. Later, quantitative samplings were carried out using a 0.20 m × 0.25 m Surber sampler with a net mesh size of 500 µm. Twenty spots per site were sampled to cover all microhabitats over a length about ten times the width of the riverbed.
Samples were stored in airtight bottles with 70 % ethanol. Specimens were sorted preliminarily in situ to remove sediment and vegetation as much as possible. The final sorting was done in the laboratory under a binocular magnifying glass to separate the specimens to species level using morphological criteria. The identification of the larvae was made using various keys and original descriptions (
Water temperature, electrical conductivity and pH.were measured using a multiparameter device (WTW Multiliner Multi 3510 IDS) (Table
Sites | Temperature (C) | Conductivity (µS) | pH | |||
---|---|---|---|---|---|---|
Mean | SD | Mean | SD | Mean | SD | |
St1 | 20 | 4 | 1921 | 441 | 7.31 | 0.35 |
St2 | 19 | 4 | 2669 | 1074 | 7.45 | 0.34 |
St3 | 22 | 4 | 8999 | 2600 | 7.31 | 0.09 |
St4 | 20 | 2 | 602 | 34 | 7.68 | 0.20 |
St5 | 20 | 4 | 885 | 129 | 7.39 | 0.10 |
St6 | 26 | 1 | 1234 | 129 | 7.54 | 0.10 |
St7 | 15 | 5 | 754 | 67 | 7.58 | 0.50 |
St8 | 16 | 3 | 829 | 208 | 7.56 | 0.39 |
St9 | 16 | 3 | 1022 | 666 | 7.39 | 0.27 |
St10 | 18 | 5 | 1441 | 1291 | 7.48 | 0.26 |
St11 | 16 | 3 | 1120 | 614 | 7.67 | 0.38 |
St12 | 19 | 2 | 1126 | 217 | 7.40 | 0.18 |
St13 | 25 | 1 | 2167 | 386 | 7.35 | 0.07 |
St14 | 26 | 2 | 8986 | 2417 | 7.30 | 0.08 |
St15 | 25 | 4 | 6431 | 3542 | 7.32 | 0.15 |
St16 | 25 | 3 | 13098 | 5095 | 7.46 | 0.31 |
St17 | 25 | 5 | 13199 | 938 | 7.42 | 0.06 |
The correlations between water temperature, electrical conductivity, pH and species richness were studied using the Pearson correlation coefficient.
We used a cluster analysis (single linkage agglomerative clustering) using Euclidean distance to cluster sites with similar species composition.
A Correspondence Analysis (CA) based on species presence/absence data (frequencies) from all sampling periods combined was used to visualize differences in species composition between sites. Subsequently environmental variables from the respective sites were fitted to the CA plot, the mean number of specimens over time was used.per each locality. RStudio (version 1.2.5019) and the packages “Vegan” (
Temperature was negatively correlated with altitude and pH (Table
Thirteen species of Ephemeroptera belonging to ten genera and five families were identified in the basin during the samplings (Table
Species\ Sites | Caenis pusilla | Caenis luctuosa | Choroterpes atlas | Baetis maurus | Baetis rhodani | Baetis pavidus | Labiobaetis neglectus | Procloeon stagnicola | Cheleocloeon dimorphicum | Cloeon simile | Oligoneuriopsis skhounate | Ecdyonurus rothschildi | Rhithrogena sp. | Species richness |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
St1 | + | + | + | + | 4 | |||||||||
St2 | + | + | 2 | |||||||||||
St3 | + | + | + | + | + | 5 | ||||||||
St4 | + | + | + | + | + | + | 6 | |||||||
St5 | + | + | + | + | + | + | + | 7 | ||||||
St6 | + | + | + | + | + | + | + | 7 | ||||||
St7 | + | + | + | + | + | 5 | ||||||||
St8 | + | + | + | + | + | + | + | 7 | ||||||
St9 | + | + | + | + | + | 5 | ||||||||
St10 | + | + | + | + | + | + | + | + | + | + | 10 | |||
St11 | + | + | + | + | + | + | 6 | |||||||
St12 | + | + | + | + | + | + | 6 | |||||||
St13 | + | + | + | + | 4 | |||||||||
St14 | + | + | 2 | |||||||||||
St15 | + | + | 2 | |||||||||||
St16 | + | + | 2 | |||||||||||
St17 | + | + | 2 | |||||||||||
Frequency | 41.2 | 88.2 | 23.5 | 17.6 | 47.1 | 100 | 29.4 | 17.6 | 23.5 | 29.4 | 5.9 | 35.3 | 23.5 |
Concerning the number of species of Ephemeroptera by sub-basin (Fig.
The family of Baetidae was the most diverse, with seven species, Baetis pavidus and Caenis luctuosa were the most widespread species, with a frequency (the number of sites where the species was found compared to the total number of sites surveyed) of 100% and 88.2% respectively (Table
The number of species richness was negatively correlated with conductivity (Fig.
The first two axes of the CA explained 47.2% of the total variation (Fig.
Among the thirteen species found in this area. seven species were recorded for the first time in the Upper Draa sub-basin: Baetis maurus, Baetis rhodani, Cheleocloeon dimorphicum, Cloeon simile, Labiobaetis neglectus, Procloeon stagnicola and Oligoneuriopsis skhounate, but no new species were recorded for the whole basin. We found four Maghrebian endemic species: Cheleocloeon dimorphicum, Procloeon stagnicola, Ecdyonurus rothschildi, Choroterpes atlas; three Iberian-Maghrebian endemic species: Baetis maurus, Labiobaetis neglectus, Oligoneuriopsis skhounate; three Palearctic species: Baetis rhodani, Cloeon simile, Caenis luctuosa; one Atlanto-Mediterranean species: Baetis pavidus; and one European-Mediterranean species: Caenis pusilla, Rhithrogena sp. was not identified to species level as only imagos can be identified specific level.
High Atlas endemic species that have been reported on the northern slopes of this mountain rangee, mainly Alainites oukaimeden and Baetis berberus (
According to topographic and climatic conditions, the Draa basin is divided into three zones: a zone at high altitude in the reliefs of the southern slopes of the High Atlas where three rivers with strong current with low conductivity and low water temperature flow (Ounilla, Mgoune and Dades), this zone is characterized by cold water species such as Ecdyonurus rothschildi, Rhithrogena sp., Baetis rhodani, Caenis pusilla and Baetis maurus. A second intermediate zone located in the valley of the Ouarzazate basin which is part of the South Atlas furrow where the climate is less cold than the high mountain zones (Iriri Fint and Ait Douchene) and where the conductivity is not very high, we find the species Cheleocloeon dimorphicum, Cloeon simile, Procloeon stagnicola, Labiobaetis neglectus and Choroterpes atlas in addition to the species of wide ecological range: Caenis luctuosa and Baetis pavidus. Finally in a third Saharan zone with high conductivity and high summer temperature (Tissint, Mghimima and Akka nait sidi) we find the resistant euryhaline species Caenis luctuosa and Baetis pavidus.
The absence of larvae of Oligoneuriopsis skhounate during all the samples collected from September 2020 to April 2021 can be explained by the phenomenon of diapause caused by the low winter temperatures (
Ephemeroptera in this area are affected by physicochemical parameters, the irregularity of the Draa rivers caused by climatic factors such as periods of summer drought, autumnal floods, or periods of high flow after snow melt (as was the case in the spring of the year 2021). Human factors also highly impact the Ephemeroptera diversity, in peculiar in relation to the intake of water from the rivers for agricultural activities, this intake is accentuated during the dry seasons which can completely dry up the river during years of severe drought. These flow fluctuations directly impact the community of aquatic macroinvertebrates whose life cycles are intimately linked to the aquatic environment.
In the Middle Draa, rainfall scarcity and repeated droughts have impacted the river’s flow, which now relies almost solely on releases from the El Mansour Eddahbi dam. The excessive use of water in agriculture further exacerbates the situation, leading to a lack of permanent water flow in the river. This has resulted in drying up of several sites which we found to be rich in macroinvertebrates in 2019. After falling dry since February 2020, we were only able to sample a small puddle that remained from dam releases and showed low macroinvertebrate richness
In our study, the distribution of Ephemeroptera was limited by conductivity with fewer species found in high saline sites, furthermore, we found a nearly significant negative correlation of species richness and water temperature. With increasing temperatures and salinity levels in the future (
Thanks to the professors Jean-Luc Gattolliat and Michel Sartori for their precious help in the identification of the species.
We also thank Khawla Lazrak for her help in measuring the physicochemical parameters in the field Funding is provided by the Museum d’Histoire naturelle de Marrakech. Cadi Ayyad University and the German Federal Ministry of Education and Research (BMBF) is funding the project SaliDraa جوج within the framework of the Strategy. Research for Sustainability (FONA) www.fona.de/en as part of its Social-Ecological Research funding priority. funding no 01UU1906 project Salidraa جوج (https://salidraajuj.uni-landau.de/).
Responsibility for the content of this publication lies with the author.
Inventory of species of Draa basin collected in all trips
Data type: List of the species sampled in the Draa basin
Explanation note: The list with the number of each species in each sample during the study period.
Parameters mesured during the samples
Data type: Database of the measured physico-chemical parameters
Explanation note: The database of the measured physico-chemical parameters in every site during all the field trips.