Northeast Tunisia Research Articles

Blending of mining wastes from the Hammam Zriba mine (Northeast Tunisia) with the primary ingredients of clinkers: an evaluation of effects on gray Portland clinker properties

The present work focuses on the effects of the blending of mining wastes from the Hammam Zriba mine (Northeast Tunisia) with the primary ingredients of Portland clinker properties. The raw mix was composed of limestone, sand, and clay sampled from the Sidi Bouzid area in Central Tunisia. The used mining wastes are composed essentially of barium, sulfur, and strontium and associated with calcium. Results show that it is possible to use these wastes to formulate an ecological clinker with high quality. The reference clinker is composed of C3S (67.8%), C2S (7.9% β-C2S and 7.15% α-C2S), and C3A (10.3%), associated with small quantities of C4AF. The incorporation of 2% of wastes does not lead to any significant change in mineral composition. The addition of 4% of wastes promotes the decomposition of alite into α-C2S (7.1 to 13.7%) and β-C2S (7.9 to 9.6%). In contrast, the clinker melt exhibits a slight drop of ferrite (5.3 to 3.1% C4AF) and a quasi-unchanged level of cubic-C3A. Greater incorporation of wastes tends to establish the mineral distribution as the reference. The amounts of free lime low when the addition of wastes is lower than 4% (< 2.28%). Higher addition (8%) shifts the free lime levels in particular for pure C3A and C3S (15.6 and 6% respectively). For the reference, free lime levels remain low (< 1%). This result bears relevant environmental and economic aspects by limiting greenhouse gas emissions, enhancing the production of low-cost gray cement, reducing the impacts of mining wastes, and opening an alternative for mining wastes management.

Effect of Lagoon and Sea Water Depth on Gracilaria gracilis Growth and Biochemical Composition in the Northeast of Tunisia

This study evaluated the growth and biochemical composition of farming Gracilaria gracilis (Stackhouse) M. Steentoft, L. M. Irvine & W. F. Farnham in the Bizerte Lagoon (BL) and Bizerte Bay (BB) in the North Coast of Tunisia, using lantern nets. Effects of site and depth on alga daily growth rate (DGR) and biochemical composition were investigated. The DGR was affected by culture site (1.42 ± 0.65% day−1 and 1.19 ± 0.34% day−1 for the BL and the BB respectively). Agar yield, was higher (p < 0.05) in the BB than the BL (23.31 ± 2.64% vs. 19.19 ± 2.32%) with a higher (p < 0.05) 3,6-anhydrogalactose (3,6-AG) contents (41.37 ± 3.68% vs 23.30 ± 5.40%) and a lower (p < 0.05) sulphate degree (6 ± 2.00% vs 8.80 ± 0.86%). The proteins contents were independent of the site and depth of culture (20.74 ± 7.22% and 22.02 ± 6.34% for the BL and the BB respectively). R-phycoerythrin (R-PE) contents were significantly higher (p < 0.05) in the BB (0.86 ± 0.31 mg g−1) than those obtained in the BL (0.33 ± 0.12 mg g−1). The salinity, transparency, nitrate and ammonium were monitored in both sites, and their influences were discussed. Our results suggest that G. gracilis cultured in Bizerte Bay can be used in a cascading biorefinery approach.

Ecotoxicity of trace elements to chicken GALLUS gallus domesticus exposed to a gradient of polymetallic-polluted sites.

Mining activity may cause heavy metal accumulation, which threatens human and animal health by their long-term persistence in the environment. This study aims to assess the impact of polymetallic pollution on chicken (Gallus domesticus) from old lead mining sites in northeast of Tunisia: Jebel Ressas (JR). Samples of soil and chickens were collected from five sites being ranked along a gradient of heavy metal contamination. Heavy metal loads were evaluated in soil samples and in chicken liver and kidney. Biochemical evaluation of oxidative stress parameters termed as Catalase (CAT), Glutathione-S-Transferase (GST), and Malondialdehydes (MDA) accumulation was monitored. Metallothionein protein level was assessed as a specific response to heavy metals. DNA alteration was achieved using MNi frequency in the investigated tissues. Finally, the evaluation of gene expression levels of CAT, GST, mt1, mt4, P53, bcl2, caspase3 and DNA-ligase was performed. Our data showed the highest loads of Cd, Cu, Zn and Pb in tissues of animals from site 3, being more pronounced in kidney. Biochemical data suggested a significant increase in antioxidant enzymes activities in all sites respect to control except in site 3 were CAT and GST were inhibited. DNA alteration was observed in all tissues being very pronounced in animals from site 3. Overall, transcriptomic data showed that genes involved in apoptosis were up-regulated in animals exposed to the most contaminated soils. Our data suggest that chicken and selected biomarkers offer a suitable model for biomonitoring assessment of heavy metals transfer through the food web in mining sites. Finally, the obtained results of heavy metals accumulation and related alterations should be carefully considered in view of the controversial relationship between distribution and toxicology of contaminants in exposed organisms.

Phenolic composition and antioxidant activities of thirteen Eucalyptus species cultivated in North East of Tunisia

This study aimed to determine the chemical composition of methanolic extracts of thirteen Eucalyptus species leaves cultivated in north east of Tunisia and their antioxidant activity was also investigated. Some of them were investigated for the first time. The total phenol and total condensed tannin contents varied significantly among species, E. lehmannii had the highest values. Significant difference was also found in total flavonoid contents and the highest one was observed in E. astringens. The HPLC analysis indicated that the main phenolic compounds were the flavonoid rutin in some species such as E. maidenii and acid gallic acid in other species as E. lehmanii. Different assays were used to evaluate the antioxidant activities; Total antioxidant activity test, DPPH radical scavenging, ABTS scavenging activity, reducing power, and β-carotene-linoleic acid bleaching. All these tests showed a high influence of the interspecific variation. However, all species exhibited interesting antioxidant activities, and DPPH radical scavenging was the most remarkable one whose all extracts were more active than the positive control. E. erythrocorys has the strongest activity with IC50 = 5.07 ± 0.54 µg/mL. All results confirmed that the secondary metabolites of these studied species could be used as a source of natural antioxidants.

Enhanced Characterization of Water Resource Potential in Zaghouan Region, Northeast Tunisia

This study presents a range of approaches to achieve enhanced characterization of the Zaghouan aquifer system (northeastern Tunisia). Existing water borehole data were analyzed to identify the different reservoir formations, while satellite imagery is analyzed to determinate the superficial lineaments affecting these formations. To define the deep structures determining the geometry of the Zaghouan aquifer system, lithostratigraphic correlations were constructed and analyzed supported by both quantitative and qualitative assessment of gravity measurements. The available lithological columns and their corresponding well logs reveal different carbonate and detritic reservoirs. The carbonate reservoirs consist of Jurassic, Cretaceous and Eocene limestones, whereas the detritic ones are composed of Oligo–Miocene sandstones and Plio-Quaternary to Quaternary sands and gravels. The structural map obtained from processing the satellite imagery confirms several lineaments drawn on the geological map, such as the Zaghouan fault, but also reveals new ones hitherto unrecognized. The intersections of the detected lineaments explain the occurrence of many springs in the area offering potentially favorable opportunities for accessing water resources in fractured aquifers. Analysis of lithostratigraphic correlations shows notable variations in the thickness, depth and composition of reservoir formations. Gravity data interpretation gives more precision by highlighting buried structures and discontinuities with different directions and depths. The delineated tectonic features demonstrate an aquifer system compartmentalized in raised and subsided blocks. The raised compartments may constitute continental divide areas and preferential aquifer recharge zones, while the sunken ones contain a multilayer aquifer composed of Quaternary and Pliocene reservoirs overlying multiple permeable layers, Tertiary and/or Mesozoic in age.

Antibacterial activities and bioactive compounds of the ethyl acetate extract of the sea cucumberHolothuria forskalifrom Tunisian coasts

AbstractPrevious scientific studies have listed chemical compounds from sea cucumber species. The ability to produce bioactive metabolites derives from their response to various ecological stresses and avoidance of predation. In view of this, the present work aimed to evaluate the antibacterial activity and quantitatively assess the active components of different organs of the sea cucumberHolothuria foskalicollected from the north-east of Tunisia. The antibacterial activity of ethyl acetate extracts was tested againstBacillus subtilis,Bacillus cereus,Escherichia coliandPseudomonas aeruginosa. It was revealed thatEscherichia coliandBacillus subtiliswere inhibited by the sea cucumber extracts. To identify the composition of these extracts, Gas Chromatography-Mass Spectroscopy (GC-MS) and Liquid Chromatography-Mass Spectroscopy (LC-MS) methods were used. The GC-MS revealed the presence of 25 major components, the most concentrated ones were characterized as C26H27N5O6Morphinan-4,5-epoxy-3,6-diol, 6 amino;C17H31F3O23-trifluoroacetoxypentadecane; C31H50O2Stigmasta-5,22-dien-3-ol,acetate; C11H14O21-Phthalanol,1,3,3-trimethyl 1-phenyl; C30H48O2Ergosta-5,22-dien-3-ol,acetate and C25H40O2(9E)-8-Phenyl-9-octadecenoic acid methyl ester; while the LC-MS revealed the presence of eight molecules, identified as phenolic acid, phytosterol and fat-soluble vitamins. Some molecules are interesting and deserve to be explored for their potential uses as ingredients in functional foods or as raw materials for new drug forms.

Laboratory bioassay exploring the effects of anti-aging skincare products on free-living marine nematodes: a case study of collagen.

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 an increasingly important source of organic matter input following a decade of expansion by the cosmetic industry. Therefore, an experiment was designed to explore the influence of collagen, the main component of commercialized skin anti-aging products, on a Mediterranean community of free-living marine nematodes from a beach in Rimel, northeast Tunisia. The effects of exposure for 30days to a control treatment and three test treatments, corresponding to three levels of sedimentary enrichment with collagen (3, 6, and 12ppm dry weight (DW)), were examined using a microcosm approach. Reductions in abundance and diversity were noted with an increase in collagen enrichment, together with a slight increase in individual weight. The presence of three species characteristic of control microcosms, Ptycholaimellus ponticus, Theristus modicus, and Kraspedonema reflectans, was clearly affected at the lowest dose; these were therefore classified as "collagen-sensitive." In contrast, the numbers of "collagen-tolerant" species, including Sigmophoranema rufum, Lauratonema hospitum, Enoploides spiculohamatus, and Trichotheristus mirabilis, increased significantly in the treated microcosms.

Econometric analysis of acceptance of soil and water conservation techniques in the semiarid region of Zaghouan (North-East Tunisia)

The Tunisian government has established some strategies to face soil erosion. In this research, we aim to study the perception of farmers towards these conservation structures in terms of the acceptability of installation of these amenities and terms of their maintenance. We try to define the socio-economic variables that explain why some farmers in the study area accept the installation of soil conservation facilities while others do not and at what rate of maintenance. Therefore, we used Tobit and Probit models to examine respectively the probability of acceptance of conservations amenities (agreement of farmers that conservation techniques be implemented on their lands) and the rate of acceptance (allocation of land for maintained CTs). It comes out that the factors affecting CTs acceptance are land size, animal husbandry, irrigation from the lake, and land tenure.

Chemical Characterization of Five Tunisian Eucalyptus Essential Oils Species.

Hydrodistillation of the dried leaves of five Eucalyptus species, E. alba Reinw. ex Blume, E. citriodora Hook., E. paniculata Sm., harvested from Choucha arboreta (region of Sejnane, northwest of Tunisia), E. pimpiniana Maiden from Mjez Elbab arboreta (north east of Tunisia) and E. bicolor A.Cunn ex Hook from Sidi Smail arboreta (center of Tunisia), in March 2017, afforded essential oils in yields varying from 1.3±0.2 to 6.0±0.9 % according to the species. E. citriodora provided the highest mean percentage of essential oil amongst all the species. Analysis by GC (RI) and GC/MS allowed the identification of 138 components representing 84.6-98.7 % of the total oil. The content of the different samples varied according to the species. The main components were citronellol, followed by 1,8-cineole, α-pinene, τ-cadinol, 7-epi-α-eudesmol, trans-pinocarveol, spathulenol, aromadendrene, γ-cadinene and δ-cadinene. The principal components and the hierarchical cluster analyses separated the five leaf essential oils into three groups, each group constituted a chemotype.

Infestation rate of lice on donkeys in Northeast Tunisia.

The present survey was carried out during autumn 2013 (September, October and November) in five localities of Jendouba district. A total number of 300 donkeys were examined and all present ectoparasites found on animals were collected and examined under stereomicroscope. The infestation rate by lice was estimated to 12.7% (38/300) there was no difference between infestation rates in males (11.5%; 22/192) and females (14.8%; 16/108). The highest infestation rate was observed in donkeys aged between 10 and 14years, they represented 19.6% of the infested donkeys. Two lice species were collected with no statistically difference between the two infestation rates: Haematopinus asini (4%; 12/300) and Bovicola ocellatus (5.3%; 16/300). The lice were collected from donkeys of the five regions with no statistically difference between the infestation rates. A specific programme to control these parasites is recommended to improve the welfare of the working donkeys in Tunisia and in other North African countries.

Infestation of small ruminants by the metacestode stage of Taenia hydatigena in slaughterhouse, North East Tunisia

Background Cysticercus tenuicollis (larvae of Taenia hydatigena) is a frequent cosmopolitan endoparasite of ruminants. The infestation by this parasite is underestimated since it is neither zoonotic nor inducing high economic losses in the sheep sector.MethodsThis study aimed at estimating different parasitological indicators, Cysticercus tenuicollis infestation in small ruminants using a slaughterhouse‐based survey in Northeast Tunisia. A total number of 3,692 sheep and 78 goats were examined in the slaughterhouse of Menzel Temime.ResultsThe overall prevalence was estimated to be 2.8 (106/3692) and 8.9% (7/78) in sheep and goats, respectively. The abundance in these two species was 0.24 and 0.05 and the intensity 1.97 and 2.85, respectively. In goats, all the cysts were found in the mesentery, whilst, in sheep, the majority were in mesentery (96%) but also on the liver in 2% of the cases and in both organs (2%). There were only cysts with aqueous liquid with predominantly middle‐sized cysts (1 to 3 cm) corresponding to 63.15 and 70.34% in sheep and goats, respectively.ConclusionSince, in small ruminants, the infestation by C. tenuicollis indicators are not high, low cost control measures should be implemented to eliminate this parasite in Northeast Tunisia.

A GIS-based tool for automatic extraction of drainage anomalies. A case study of enfidha (North-East of Tunisia)

It is particularly useful to analyze drainage anomalies for morphostructural interpretation of low relief areas. In basins and sub-basins, these anomalies may be due to local changes resulting from lithological discontinuities or tectonic activity caused by subsidence or uplift. Indeed, drainage anomalies are the most revealing geomorphological evidence of active faults. We present a new method to extract the drainage anomalies in watershed. The adapted methodology is therefore based on the drainage anomalies extraction in the Enfidha plain, indicating that the area is potentially tectonically active. Our objective in this article is to develop an automatic extraction tool, using the model builder technique in the ArcGIS environment, to extract drainage anomalies. To use this tool, a Digital Elevation Model (DEM) and drainage networks are required. In order to obtain the desired results, several tools are used: filtering of the DEM, generation of the summit surface, extraction of the slope orientation, calculation of the stream direction, etc. Based on the Automatic Drainage Anomalies Extraction Tool (ADAET), the relationship between drainage anomalies and tectonics was studied in the Enfidha sector of north-eastern Tunisia. The sub-watershed selected for this study is drained by numerous rivers and occupies the northeastern part of the Enfidha plain. This plain is known for its relatively high seismicity. Therefore, the method of automatic extraction of drainage anomalies in a GIS environment based on a global DEM (SRTM), detailed in this paper, appears very promising and can be of great utility in morpho-structural and morpho-neotectonic studies. This method allows to discover a high concentration of drainage anomalies on the Oued El Boul river and in the plain. Correlation with existing tectonic models shows that parts of the selected drains are located near the subsurface fault. Therefore, the drainage anomalies prove the existence of neotectonic deformation in the terrain. The activity of this fault has been proven by several authors. In this region, the extraction of drainage anomalies is most often used and reflects neotectonic activities.

Occurrence of Ectoparasites in Backyard Domestic Chickens (Gallus gallus domesticus) in the Northeast of Tunisia

Occurrence of Ectoparasites in Backyard Domestic Chickens (Gallus gallus domesticus) in the Northeast of Tunisia

Prevalence and Antibiotic Resistance Patterns of Campylobacter spp. Isolated from Broiler Chickens in the North of Tunisia.

The aim of the current study is to assess the prevalence of Campylobacter infection in broiler chickens, raised in intensive production conditions, and to evaluate the antimicrobial susceptibility of recovered Campylobacter isolates. A total of 590 cloacal swab samples were taken from 13 broiler chicken flocks in the North East of Tunisia. All samples were tested for the presence of thermophilic Campylobacter by culture and PCR, targeting the mapA and ceuE genes, respectively. Susceptibility to antimicrobial drugs was tested against 8 antibiotics. Prevalence of Campylobacter infection, relationship with geographic origins and seasons, antimicrobial resistance rates and patterns were analyzed. Total prevalence of Campylobacter infection in broiler flocks was in the range of 22.4%, with a predominance of C. jejuni (68.9%), followed by C. coli (31.1%). Positive association was highlighted between the infection level and the season (P < 0.001), but no link was emphasized considering the geographic origin. Antimicrobial susceptibility testing revealed very high resistance rates detected against macrolide, tetracycline, quinolones, and chloramphenicol, ranging from 88.6% to 100%. Lower resistance prevalence was noticed for β-lactams (47% and 61.4%) and gentamicin (12.9%). 17 R-type patterns were observed, and a common pattern was found in 30.3% of isolates. This study provides updates and novel data on the prevalence and the AMR of broiler campylobacters in Tunisia, revealing the occurrence of high resistance to several antibiotics and emphasizing the requirement of better surveillance and careful regulation of antimicrobials use.

Aptian\u2013Albian shale oil unconventional system as registration of Cretaceous oceanic anoxic sub-events in the southern Tethys (Bir M\u2019Cherga basin, Tunisia)

The Bir M’Cherga basin (North-east Tunisia), with about 600 km2 area, had recorded four Middle Cretaceous source rocks well stratigraphically correlated with the four known oceanic anoxic sub-events: OAE1a, OAE1b, OAE1c, and OAE1d. Variety of lithology, thickness and organic richness had characterized these source rocks. The sedimentary tectonic analysis, the petrology and geochemistry study established the petroleum system of these source rocks. Basin formation began early in the Barremian–Aptian interval by synsedimentary tectonics reactivating old basement faults. During the Aptian–Albian, the formed basin had a depocenter that recorded thicker black shales while its NW and SE edges remained raised under the Triassic halokinetic activities. The evolution of the sedimentary filling during this period generated two sedimentary cycles corresponding to two filling second-order fining and thickening upwards sequences. The black shales that constitute these source rocks are formed between subtidal and external platform environment and are interbedded with juxtaposed high organic rich layers and poor ones. The rich organic facies consists of dark shale that constitutes the source rock. The poor organic beds formed by light grey and nodular limestones constitute an intra host reservoir. Thereby, petroleum system consists in an “unconventional oil shale hybrid systems with a combination of juxtaposed organic-rich and organic-lean intervals associated to open fractures”. The kerogen is essentially amorphous, with marine planktonic origin and low ligneous organic matter contribution. This organic material of dark facies had been well preserved in an anoxic environment with little or no energy. Light grey limestones were of oxic-to-sub-oxic environment. The stage of the thermal evolution for these source rocks provided by IH/Tmax diagram is of the “oil window”. The average transformation ratio (TR) is estimated as 45% suggesting thus black shales are oil shale resources which still close about untransformed 55% of its hydrocarbon generating potential. The expulsion and release of oil into these source rocks are proven by the observation of hydrocarbons filling micro-cracks and by the variable values of the oil saturation index OSI ranging from 0 to 138%. The latter exceeds 100% near the paleo-high reliefs indicating two “oil crossover” areas attributed to the high degree of oil source rock saturation and accumulation of hydrocarbons considered ideal for hydraulic fracturing. This oil crossover is a consequence of secondary migration into black shale source rock, achieved by various faults created during the distensive phase that were reactivated again several times.

Sediment-water column exchange of persistent organic pollutants (PAHs and PCBs) and their transport vector in El Bey watershed, Tunisia

El Bey river, which drains 60% of the pollutant load of several urban cities in the northeast of Tunisia, provides a good example of the transfer of organic and metallic pollutants that result from industrial and urban activity, and can be used to show how these charges are transported and discharged into the Gulf of Tunis. Persistent organic pollutants (PAH and PCB) in dissolved, particulate matter, bed sediments, and three wastewater effluents in El Bey watershed were analyzed. PAH (∑14PAHs) concentration ranged from 0.248 to 9.955 mg L−1 and from 0.836 to 28.539 mg L−1 in dissolved and particulate fraction respectively. The particulate/dissolved partition coefficient value (Kd) was less than one which confirmed the affinity of PAH to be adsorbed. In sediment, the high-molecular weight PAHs were found principally with percentage between 50 and 100% witch present 239.99 to 5362.19 μg kg−1, which is relatively higher in comparison with other estuaries river. Contrary to PAH patterns, PCB were bound to dissolve fraction. Kd (PCB) value (Kd > 1) reflected this affinity which is related to environment energy. The spatial distribution and profile of analyzed organic pollutants confirmed the direct impact of wastewater effluent on the organic pollution level in three compartment of El Bey watershed and his profiles suggested different transport patterns.

Tracing groundwater salinization processes in an inland aquifer: A hydrogeochemical and isotopic approach in Sminja aquifer (Zaghouan, northeast of Tunisia)

Sminja plain is an inland aquifer in Zaghouan prefecture, northeast of Tunisia. In some parts of the aquifer, salinity exceeds 13 g L−1, which poses serious problems to the safe use of the groundwater in irrigation and drinking purposes.The present work aims to delineate the saline water plumes and to understand their salinization processes. A field survey including surface water and groundwater sampling was conducted. The taken samples were analyzed for major chemical elements (Na+, Ca2+, Mg2+, K+, Cl−, SO42− and NO3−) and stables isotopes composition (18O and 2H). The geochemical data were used to characterize and classify the water samples. Stable isotopes are useful tools to understand recharge processes and to differentiate between salinity origins. Indeed, the saline groundwater zones are concentrated in the center, the north-west (Aziz mountain) and south-west parts of the plain (City Al Fahs). The evolution of the groundwater salinization according to the main flow direction is principally caused by rock-water interaction which is mainly represented by the dissolution/precipitation of minerals dispersed in the saline reservoir formation and ion exchange reaction. Stable isotopes signature indicates that some water samples are originated from the infiltration of modern precipitation. Non-evaporated water is rapidly infiltrated to the saturated zone with relatively lower contents of δ18O and δ2H. Thus, most of the samples are presenting enrichment in heavy isotopes which highlight the occurrence of evaporation process of meteoric water prior to groundwater recharge. Furthermore, anthropogenic phenomenon represented by the return-flow of irrigation water and the use of nitrogen fertilizers were identified as non negligible contamination sources in the northeastern part of the aquifer near the irrigated perimeters. These wide variations in water salinity indicate variability in geochemical process controlling aquifer water mineralization in Sminja plain.

Spatial and Temporal Variations of Water Quality of Mateur Aquifer (Northeastern Tunisia): Suitability for Irrigation and Drinking Purposes

The present study aims to assess the spatial and temporal variations of the hydrochemical characteristics of Mateur aquifer groundwaters, a crucial water resource in the northeast of Tunisia. The aquifer was subject to water quality deterioration due to salinization and nitrate contamination, and a new assessment of water quality was needed. For this purpose, 40 groundwater samples were collected during wet and dry seasons and analyzed for salinity, pH, T, O2, major cations and anions, and nutrient elements using standard methods and Water Quality Index (WQI). The results showed that most of the groundwater parameters were not within the permissible limits set by the World Health Organization in both seasons. The geochemical data were interpreted using WQI for drinking water. The spatial distribution maps of Water Quality Index showed that the highest quality was found, during both seasons, in the northwest and the southeast part of the aquifer, corresponding to the recharge zone, whereas the poor and very poor water quality was found in the outflow part of the aquifer. According to sodium adsorption ratio (SAR) and Na% values, most of the groundwater samples were not suitable for irrigation purposes and characterizing the eastern part of the aquifer and the outflow part of the aquifer, around the Ichkeul marshes.

Ceratomyxa gouletti n. sp. (Myxosporea: Ceratomyxidae), a parasite of the red scorpionfish Scorpaena scrofa (L.) from Tunisian waters.

Ceratomyxa gouletti n. sp. is a new parasite described from the gallbladder of the red scorpionfish Scorpaena scrofa (Scorpaeniformes: Scorpaenidae) collected from La Goulette in the Northeast of Tunisia. The parasite develops disporic plasmodia, elliptical to ovoid in shape, measuring up to 33.1 ± 3.6 (28.0-38.2) μm in length and 12.5 ± 2.1 (11.3-14.0) μm in width. Mature spores are elongated transversely and crescent-shaped with rounded ends and unequal shell valves, measuring 8.1 ± 1.27 (7.2-9.0) μm in length and 32.0 ± 2.5 (27.0-38.2) μm in thickness. Sutural line is straight and visible between valves. Polar capsules are subspherical with 3.15 ± 0.63 (2.7-3.6) μm long and 1.9 ± 0.14 (1.8-2.0) μm wide. Posterior spore angle is slightly concave 160°-175°. Molecular analysis based on the small subunit 18S rDNA sequence shows that C. gouletti n. sp. is different from all other ceratomyxid species DNA sequences in GenBank. Phylogenetic trees clustered the new species with long-branching Ceratomyxa species, and it was closely related to the species Ceratomyxa longipes from two gadid fish hosts with 89% bootstrap support.

Paleoenvironmental and ecological changes during the Eocene-Oligocene transition based on foraminifera from the Cap Bon Peninsula in North East Tunisia

Biostratigraphic analysis of the Eocene-Oligocene transition (E-O) at the Menzel Bou Zelfa and Jhaff composite section in the Cap Bon Peninsula (North East Tunisia) allowed us to recognize a continuous planktic foraminiferal biozonation: E14 Globigerinatheka semiinvoluta Zone, E15 Globigerinatheka index Zone, E16 Hantkenina alabamensis Zone and O1 Pseudohastigerina naguewichiensis Zone. A quantitative study of benthic and planktic foraminifera assemblages was carried out and the richness and diversity of foraminifera allowed us to reconstruct the paleoenvironmental evolution from marine to terrestrial environments. From the Eocene E14 Zone, the foraminiferal association characterizes a relatively warm climate with considerable oxygen content and a dominance of keeled and spinose planktic foraminifera, which became extinct at the E/O boundary, possibly due to cooling of the planktic environment. Nevertheless, the small benthic foraminifera do not show an extinction event at the Eocene/Oligocene (E/O) boundary, indicating that the benthic environment was not significantly affected. In the basal Oligocene O1 Zone, the benthic environment changes to a shallower setting due to cooling of the climate. These changes generated a remarkable dominance of globular forms in the planktic environment. Small benthic foraminifera apparently have a gradual extinction event, or more likely a gradual pattern of local disappearances, that could have been caused by the Oi1 glaciation.