Inventory and new records of benthic amphipods from macrophytes and fine sand communities of the Bizerte lagoon (Tunisia, SW Mediterranean Sea)

Marwa Khammassi,Sarra Laabidi,Mohamed Sghaier Achouri,Wahiba Zaabar,Jérôme Jourde,Pierre-Guy Sauriau

doi:10.1186/s41200-019-0182-5

Abstract

Shallow water benthic communities from the Bizerte lagoon (northern Tunisia) were investigated at 33 stations sampled in April and July of 2016 and 2017. A total of 18 amphipod species were recorded among which two new species were recorded: one for Tunisian coasts (Jassa marmorata) and a second one for the Mediterranean Sea (Serejohyale spinidactylus). In addition, and compared to previous studies, nine amphipod species were collected for the first time in this lagoon. Amphipod assemblages were numerically dominated by the families Melitidae (28%), Caprellidae (14.5%) and Ampithoidae (11.7%). Three species: Cymadusa filosa, Dexamine spinosa and Elasmopus rapax were numerically dominant. According to their biogeography, most of the recorded amphipod species (11–18) showed an Atlantic–Mediterranean distribution, whereas four were cosmopolitan and three lessepsian Indo-Pacific migrants, but no species were Mediterranean endemic. Specimens of both Jassa marmorata and Serejohyale spinidactylus are illustrated and described.

Highlights

The Order Amphipoda is a large group of crustaceans, shrimp–like in form, that inhabit various environments, mainly aquatic, from fully marine to fresh water including hypogean habitats (Sket 1999)
A total of 6058 amphipods belonging to 18 species, 16 genera and 12 families, were collected in the Bizerte lagoon during April and July of 2016 and 2017
Eight species displayed relative abundance values higher than 5% (Table 1): Cymadusa filosa Savigny, 1816 was the most abundant species (11.7%), followed by Dexamine spinosa (Montagu, 1813) (11.1%) and Elasmopus rapax Costa, 1853 (11%) and they were largely distributed within the lagoon between 0.5–1, 0.5–4 and 0.5–10 m depth, respectively

Summary

Introduction

The Order Amphipoda is a large group of crustaceans, shrimp–like in form, that inhabit various environments, mainly aquatic, from fully marine to fresh water including hypogean habitats (Sket 1999). Mediterranean amphipod communities show a high species diversity with more than 452 recorded species (Ruffo 1998) inhabiting a large variety of habitats from coastal, including estuarine and brackish conditions, to the abyssal level. The Bizerte lagoon is a shallow water Mediterranean ecosystem located in northeast Tunisia (Fig. 1). It plays a major hydrological transition role between the Mediterranean Sea and the Ichkeul Lake (Afli et al 2008), known to be an important area of nursery and feeding grounds for marine, estuarine and freshwater species (Shaiek et al 2015). New investigations on amphipod communities (Zaabar et al 2015) reported the presence of 10 amphipod species at the Menzel Jemil station (St27) (Fig. 1)

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Discussion

Conclusion