Assessment of functional feeding groups (FFG) structure of aquatic insects in North- western Rif - Morocco

Abstract

The involvement of trait-based approaches is crucial for understanding spatial patterns, energy flow and matter transfer in running water systems, which requires consistent knowledge of the functional structures of aquatic communities, with the advantage of combining physical properties and behavioral mechanisms of food acquisition rather than the taxonomic group. The present study indicated how functional feeding groups may be used as a proxy for classical taxonomic evaluation, as well as the potential interest in incorporating them as indicators of anthropogenic stressors. The composition and abundance of the functional feeding groups of aquatic insects were examined from September 2021 to August 2022 along the Western Rif Region. Benthic samples were collected from nine sampling points in the studied area using a Surber sampler with a mesh size of 500 µm and a diameter of 20*20 cm. The stations included in this work were chosen for their accessibility as well as their position on the hydrographic systems. The abundance of sampled aquatic organisms in the whole study area revealed 5,342 individuals belonging to 60 families and seven orders of aquatic insects, classified into five feeding functional groups. In terms of abundance, Collector-gatherers (Ephemeroptera and Diptera) were the most abundant trophic group at most of the sites, with a proportion of 38.47%. Predators (Coleoptera, Hemiptera and Odonata) were the second group at all sites, followed by Collector-filters, accounting for 39.53%, 28.14% and 22.37% respectively, while Scarpers and Shredders had the lowest representation across all sites with 4.16%. The high number of registered Collectors could be related to their ability to feed on a diverse range of food items compared to the remaining trophic guilds. According to the Canonical Correspondence Analysis results, physicochemical (i.e. T, pH, BOD5, Cl- and NO3-) and hydromorphological (i.e. current velocity and depth) variables were amongst the key predictors of shaping the functional structure of aquatic biota during this investigation. It is highly recommended to carry out suitable measures to largely attenuate anthropogenic pressures in order to preserve the integrity of freshwater bodies and their biota.

Low redundancy among caddisflies sharing a mid‐mountain stream

“…The isotopic values measured in the Gilgil invertebrate assemblage broadly confirmed trophic niche attribution according to highly cited reference guidelines such as Merritt and Cummins (1996), Merritt et al (2002Merritt et al ( , 2008 and Dobson et al (2002) utilised by researchers working in the Afrotropics (Benjamin et al, 2023, El Yaagoubi et al, 2023, Edegbene et al, 2021, Masese et al, 2014a, despite acknowledged discrepancies between temperate and tropical keys (see Masese et al, 2014a and references therein). At the same time, however, the relative positioning of the Gilgil invertebrates across the isotope biplot provided new insight into the potential role of these taxa within Afrotropical stream food webs.…”

“…(2002, 2008) and Dobson et al. (2002) utilised by researchers working in the Afrotropics (Benjamin et al., 2023, El Yaagoubi et al., 2023, Edegbene et al., 2021, Sitati et al., 2021, Masese et al., 2014a, 2018, etc. ), despite acknowledged discrepancies between temperate and tropical keys (see Masese et al., 2014a and references therein).…”

Odonata, Coleoptera, and Heteroptera (OCH) Trait-Based Biomonitoring of Rivers within the Northwestern Rif of Morocco: Exploring the Responses of Traits to Prevailing Environmental Gradients

“…The portable Pastel UV analyzer was used to perform the examination. The stringent analysis procedure followed Rodier's recommendations [56][57][58][59], guaranteeing accuracy and adherence to the recommended methods for monitoring water quality. Furthermore, the nutrient content of the water samples was analyzed, including the levels of nitrites (NO −2 mg/L), nitrates (NO −3 mg/L), chlorine inputs (Cl − mg/L), and complexometric calcium (Ca 2+ mg/L).…”

“…It is noteworthy that most of the chosen sites display a Mediterranean hydrological regime, which is typified by a high degree of irregularity. This hydrological pattern is characterized by extreme summer droughts and powerful winter floods that have a major influence on the flow regime [55,56]. This study is important because it sheds light on the intricate dynamics of the freshwater systems under study in Morocco while taking place in the distinctive ecological framework of the northwest Rif region.…”

A new species of the Baetis fuscatus group (Ephemeroptera, Baetidae) from Morocco

“…Encompassing an area of 30,000 km 2 (Fig. 1 ), the Rif stretches approximately 90 km from north to south and spans 340 km from east to west ( El Alami and Dakki 1998 ; Errochdi et al 2012 ; El Yaagoubi et al 2023 ).…”