Amphipods from tidal channels of the Gulf of Gabès (central Mediterranean Sea)

Abstract

The spatial and temporal species richness, abundance and assemblage structure of amphipods from four tidal channel of the Gulf of Gabès were studied at 26 stations and during four seasons from March 2016 to January 2017. This led to the identification of 4,278 individuals, 45 species and 21 families. The four mostly diversified families are the Ampeliscidae (6 species), the Caprellidae (5) and the Aoridae and Maeridae (4 species both), while three families account for ~ 75% of the individuals: Aoridae (45.5 %), Corophiidae (20.5%) and Dexaminidae (7.2%). The species richness and abundance were higher in winter than at other seasons. The fauna is dominated by a small number of species characteristic of areas with detritus accumulation and seagrass meadows, including Microdeutopus anomalus, Monocorophium acherusicum, Dexamine spinosa, Microdeutopus gryllotalpa, Cymadusa filosa and Elasmopus rapax, which are commonly recorded in lagoons and coastal shallow waters of the Mediterranean Sea. The amphipod structure is linked to the location of tidal channels in the Gulf of Gabès. Abundances are low in the Kerkennah channel compared with other channels, especially the Maltine channel with high winter accumulation of organic matter. There are also low abundances in high-energy hydrodynamic zones with gravel sediment; conversely, the presence of macrophytes, mainly in the seagrass meadows, increases amphipod diversity. As a result of this study, five new species can be added to the inventory of the Tunisian marine amphipod fauna, including a non-native species for the Mediterranean Sea, Paracaprella pusilla.

Do intertidal Zostera noltei meadows represent a favourable habitat for amphipods? The case of the Kneiss Islands (Gulf of Gabès: Central Mediterranean Sea)

“…We also record 78 taxa belonging to 22 families associated with eelgrass beds in the intertidal zone of the Kneiss Islands. Conversely, 26 species reported by Fersi et al (2018) are found in the subtidal tidal channels of the Kneiss, of which only 12 species are in common between the intertidal and subtidal ecosystems. During this study, a relatively high number of amphipod species associated with Z. noltei meadows were recorded on the south‐eastern coast of Tunisia (78 species) when compared to other sites in the Mediterranean (44 species).…”

“…Sediment grain‐size and organic matter content play a significant role in controlling the distribution of the amphipod communities in the Kneiss Islands. Contrariwise, the distribution of amphipods in the Kneiss subtidal channels appears mainly linked to the presence of algae and phanerogams and the availability of detritus (Fersi et al, 2018), which are the same factors responsible for the amphipod distribution in the Bizerte Lagoon (Zaabar et al, 2015). In other localities, several authors (Guerra‐Garcia et al, 2014) have obtained the same results as observed in the Kneiss Islands concerning the amphipod distribution.…”

“…For example, along the Tunisian coast, Zakhama‐Sraieb et al (2011) have studied the structure, diversity and spatial distribution of the amphipod fauna, recording 44 species belonging to 12 families associated with the Posidonia meadow habitat. Based on a seasonal monitoring survey in 2016–2017, Fersi, Dauvin, Pezy, and Neifar (2018) have recorded 45 amphipod species and 21 families in four subtidal channels of the Gulf of Gabès. The amphipod fauna is dominated by a small number of species characteristic of areas with detritus accumulation and seagrass meadow, mainly composed of Posidonia oceanica , Cymodocea nodosa and Halophila stipulacea.…”

Ecological status assessment and non-indigenous species in industrial and fishing harbours of the Gulf of Gabès (central Mediterranean Sea)

“…However, there are few quantitative studies designed to examine soft-bottom communities and the impacts of NIS in soft sediment habitats (Travizi et al 2019). In Tunisia, the majority of benthic macrofauna studies have focused on macrobenthic communities of shallow coastal areas (i.e Khedhri et al 2014;Fersi et al 2018;Boudaya et al 2019;Mosbahi et al 2017Mosbahi et al , 2019Mosbahi et al and 2020.…”

Unravelling the origin and introduction pattern of the tropical species Paracaprella pusilla Mayer, 1890 (Crustacea, Amphipoda, Caprellidae) in temperate European waters: first molecular insights from a spatial and temporal perspective

“…In 2014, several individuals of P. pusilla were found at Zikim on the southern coast of Israel, the first record of this species in the eastern Mediterranean Sea (Ros et al 2016a). Most recently, P. pusilla has been reported in the central Mediterranean, in the Gulf of Gabès in tidal channels of the Kneiss archipelago (Tunisia) (Fersi et al 2018). Thus, by its presence in western, central, and eastern regions of the Mediterranean, we suggest that P. pusilla might be present more generally throughout the Mediterranean and that it might have been overlooked due to its small size or temporal instability.…”