Mohamed Allouche

University of Carthage | UCAR · Département de Sciences de la vie

An experiment was conducted using microcosms with connected sedimentary compartments to assess the effects of three polycyclic aromatic hydrocarbons (PAHs) on free-living marine nematodes from Bizerte Bay (northeastern Tunisia). Over 30 days, the nematofauna were exposed to four treatment sediments, including one with chrysene (150 ppb), chrysene (...

A laboratory bioassay was performed to assess the ecotoxicity of ciprofloxacin on a meiobenthic nematodes community from Bizerte lagoon (NE Tunisia). Four ciprofloxacin doses [D1 (50 µg/g), D2 (100 µg/g), D3 (200 µg/g), and D4 (500 µg/g)] were applied to the substrate, and responses were studied after one month. Discernible differences were observe...

Coastal ecosystems are exposed to pollution by various contaminants due to several anthropogenic activities. Numerous pollutants, such as pesticides, drugs, metals , Polycyclic Aromatic Hydrocarbons (PAHs), Brominated flame retardants (BFRs), and Microplastics (MPs), transported in the water column tend to persist in the sediments. Among the Tunisi...

An experiment conducted with 'open microcosm' made by connected sedimentary compartments with different qualities was for 30 days to evaluate the migratory behaviour of nematodes as induced by exposure to pyrene. The nematofauna was collected along with sediment from a reference site in Bizerte lagoon. Following one week acclimatization period, the...

Polycyclic aromatic hydrocarbons (PAHs) are toxic for humans and marine fauna alike. The current study assessed the impact of PAHs on the migratory behaviour of meiobenthic nematodes collected from the Bizerte lagoon, Tunisia. The experiment lasted for 15 days and was carried in open microcosms, which comprised a lower, contaminated and an upper, u...

Increasing concentrations of the antidepressants amitriptyline and paroxetine were determined recently in marine habitats. However, their impact on marine biota is understudied, despite multiple undesirable effects they have on the environment. An important behavioral aspect that is increasingly measured following exposure to contaminants is the mi...

The effects of microplastics and sorbed polycyclic aromatic hydrocarbons at community levels were rarely assessed in laboratory experiments, despite their obvious advantage in reflecting better the natural conditions compared to traditionally single species-focused toxicological experiments. In the current study, the multifaceted effects of polyvin...

The toxic effects of two commonly used glucocorticoids, the dexamethasone and prednisolone, on meiobenthic nematodes were assessed in a laboratory experiment for 30 days. Nine treatments were employed, comprised of two single and mixed concentrations of dexamethasone and prednisolone (i.e., 0.14 and 1.4 µg·L−1). The exposure to both glucocorticoids...

Marine ecosystem represents an ecologically and economically important water bodies for human and animal living. Their increasing pollution by persistent organic pollutants has represented a major environmental alarm during the last years. In the current study, we examined the occurrence, local distribution and ecotoxicological menace of organic po...

An open experimental setup was established in order to explore the toxic effects of the antidepressant paroxetine on meiobenthic nematodes. Three types of microcosms made from polyvinyl chloride tubes, each comprising two sediments compartments (upper and lower), were used in a laboratory experiment for 15 days. The experimental setup targeted the...

The ecotoxicological effects of beta-blockers (i.e. Diltiazem and Bisoprolol) and their interactions with the microplastic polyvinyl chloride on marine meiofauna were tested in laboratory microcosms. An experimental factorial design was applied, using meiobenthic fauna collected from the Old Harbor of Bizerte (NE Tunisia), but with a main focus on...

A microcosm experiment was carried out to provide a deeper insight into the toxic mechanisms exerted by two lipid regulator agents, as well as their interactions with the polyvinyl chloride microplastic on marine meiofauna. Two concentrations of Atorvastatin “A” and of Simvastatin “S”, (i.e., 0.6 mg.kg−1 and 6 mg.kg−1), as well as a single dosage o...

Coastal marine systems are the most sensitive zones to emerging pollutants. The present study aims to investigate the effect of Diuron on the meiofaunal assemblages, collected from the Bizerte channel (Tunisia). Microcosm experiments were set up using four increasing Diuron concentrations [D1 (10 ng g􀀀 1 dry weight (DW)), D2 (50 ng g􀀀 1 DW), D3 (25...

In this study, a microcosm experiment was conducted for 30 days to assess the impact of the presence of juvenile gray shrimp Crangon crangon on meiofauna. The results suggested that juvenile shrimp had a significant negative impact on the abundance of nematodes and copepods, but no effect on polychaetes. Moreover, nematodes showed a significant dec...

The response taxonomic and trophic of meiobenthic organisms, especially marine nematodes to polybrominated diphenyl ether (BDE-47) was studied using a community from Bizerte lagoon (Nord-East Tunisia). Four concentrations of BDE-47 [D1 (2.5 ug/kg dw), D2 (25 ug/kg dw), D3 (50 ug/kg dw), and D4 (100 ug/kg dw)] were applied, and responses were determ...

Numerous studies have focused on the response of meiofauna after exposure to polycyclic aromatic hydrocarbons (PAHs), but none has been devoted to their uptake into nematode body compartments. The present study monitored PAH uptake by Oncholaimus campylocercoides which was selected after 40 days in the laboratory through original protocols from nat...

Meiobenthic nematodes are well-known bioindicators in aquatic ecosystem health programs. However, the explored taxa are still limited and practically devoted to the community level. The present study provided a new method of experimental isolation of a species from a pristine nematofauna. In our method, the nematofauna faced two types of sediment,...

Trophic web structuring in aquatic sediments is dependent on the biological interactions between metazoans and microbial communities. The presence of pollutants in these biotas can therefore impact the meiofauna structure via the modification of the microbial communities. The current study examined in a laboratory bioassay the response of meiobenth...

A microcosm experiment was conducted to evaluate the impacts of the fluoroquinolone antibiotic ciprofloxacin on meiobenthic taxa abundance, nematode genus structure, and functional trait parameters. Sediment samples were experimentally enriched with four different doses of ciprofloxacin [D1 (50 ppm Dry weight ‘DW’), D2 (100 ppm DW), D3 (200 ppm DW)...

An experiment was carried out using microcosms to evaluate the impact of the fluoroquinolone antibiotic on nematode trophic groups structure and bacterial abundance. Sediment samples were experimentally enriched with four increasing doses of ciprofloxacin [D1 (50 ppm), D2 (100 ppm), D3 (200 ppm) and D4 (500 ppm)] and compared to non-enriched sedime...

A microcosm experiment was carried out to study the ecotoxicity and interactions between heavy metals and Polyvinyl chloride microplastics. Fifteen treatments were tested and results were examined after one month. In details, this work aims to study the ecotoxicological effects of cadmium (10 and 20 mg kg⁻¹ Dry Weight DW), polyvinyl chloride (PVC)...

Recently, ivermectin was confirmed as an effective COVID-19 treatment. A significant amount of ivermectin could deposit into sediments of the semi-closed Mediterranean Sea, where three European COVID-19 epicenters are located: Italy, Spain, and France. We exposed meiobenthic nematodes to three ivermectin doses (1.8 ng.g⁻¹, 9 ng.g⁻¹, and 18 ng.g⁻¹)...

Organic enrichment due to human impact is one of the major threats that affect benthic communities in semi-enclosed marine ecosystems, such as the Mediterranean Sea. However, many emerging sources of organic pollutants, such as those released to nature through human practices related to esthetics and cosmetics, remain underestimated, despite being...