OPENMODS 2.0 “Instrument Jamming Meeting” report

Major achievements The feedback provided by potential users on their needs was very much appreciated. They underlined the importance of having: ● an easy to deploy instrument (i.e.: from small fishing boats); ● multi-parameter sensors in ONE device; ● less maintenance effort and prioritized the variables to measure. Although, there are technical limitations and different solutions and there is no one tool that can do everything, which is low cost, has high resolution and low maintenance, the outcomes of the platforms/sensors/communications working group meet the main requirements that emerged. Priority was given to: ● a platform that will operate in drifter mode which is extremely easy to deploy and perfect for studies associated with search and rescue operations (another need that has emerged). It also constantly guarantees the knowledge of the instrument position. The platform can be easily converted into the moored mode. ● temperature and pressure sensors. The sensors will be low -cost with the idea to replace them rather than calibrate them; ● LoRaWAN communications preferably with Bluetooth integration for the in-situ download of the data

Reproductive biology of Klein’s sole, Synapturichthys kleinii (Actinopterygii: Pleuronectiformes: Soleidae), off Tunisian coast (central Mediterranean)

Background. Klein’s sole, Synapturichthys kleinii (Risso, 1827), is a rare fish, included in the IUCN Red List as Data Deficient, and its biology is poorly known. Biological investigations of S. kleinii have been surprisingly rare in Tunisian waters. In the presently reported study, we investigated the reproductive period, size at first sexual maturity, and fecundity of S. kleinii along the Tunisian waters, with the aim of achieving the first complete and comprehensive description of the reproduction of this fish in the Mediterranean Sea. Materials and methods. A total of 294 specimens of S. kleinii were sampled over two years, off the Tunisian coasts. Sex ratio was estimated through the seasons of the year and the size classes. The stage of maturity was determined macroscopically only for females. Monthly gonadosomatic index (GSI), monthly hepatosomatic index (HSI), and condition factor (K) were calculated for males and females of S. kleinii. Size at first maturity was estimated only for females during the spawning season. Eighteen mature females at spawning stage were collected, weighed, and fixed in 4% formaldehyde solution for fecundity estimation. Results. Annual sex ratio showed significant differences between males and females. In specimens exceeding 27 cm in total length females outnumbered males significantly. The Klein’s sole reproduction period started in October and ended in January. The gonadosomatic index reached highest values in November for females and males. Females attained sexual maturity at 20.53 cm total body length (TL). Total fecundity ranged from 3647 to 23 174 eggs. We found a low correlation coefficient between total fecundity and total length, but a high correlation coefficient between eviscerated weight and ovary weight. Conclusion. Our results constitute a preliminary baseline for monitoring changes in the biological indexes linked to the reproduction cycle and length at first sexual maturity of S. kleinii. The presently acquired data will enable biologists to assess the status of this fish and develop culture technology in natural waters and will be useful for the fishery biologists and conservation biologists, for successful development, management, production, and ultimate conservation of this favoured Tunisian food fish

Spatial distribution and abundance of intertidal benthic macrofauna in the Kneiss Islands (Gulf of Gabès, Tunisia)

International audienceThe Kneiss islands, located in the Gulf of Gabès (Southeastern Tunisia), represent a site of international interest in terms of their ornithological diversity (Important Bird Area, SPAMI and Ramsar Site) and are heavily exploited for clams and fish resources. In an effort to assess the ecological status of the intertidal ecosystem, and to facilitate management and conservation of the resources, an ecological survey of the macrobenthic component was carried out from January to March 2012. This study involved identifying the benthic fauna and assessing the spatial distribution on the southern unperturbed Zostera noltei mudflats by human activities. A total of 102 macrobenthos taxa is identified at 19 stations with a predominance of crustaceans (37%), polychaetes (27%) and molluscs (23%). The AMBI index shows that the area has a good ecological status. Cluster Analysis and Multidimensional scaling identify three benthic assemblages on the basis of their faunal similarity in relation to sediment types and organic matter contents.RésDistribution spatiale et abondance de la macrofaune intertidale des îles Kneiss (Golfe de Gabès, Tunisie). La distribution spatiale et l'abondance des communautés macrobenthiques des îles Kneiss (Golfe de Gabès, Tunisie) ont été étudiées. Par leur diversité ornithologique, les îles Kneiss présentent un intérêt international (Site Ramsar, ZICO, ASPIM), mais l'activité de collecte de la palourde (Ruditapes decussatus) et la pêche intensive au chalut benthique ont conduit à la surexploitation des ressources. Pour évaluer l'état écologique de cet écosystème et faciliter la gestion et la conservation des ressources, une étude écologique de la composante benthique a été réalisée. La macrofaune benthique des vasières des îles Kneiss a été étudiée de janvier à mars 2012 dans une zone d'herbier de Zostera noltei peu perturbée par des activités humaines. Un total de 102 taxa de macrobenthos a été identifié dans 19 stations, avec une dominance de crustacés Amphipodes (37%), des Annélides Polychètes (27%) et des Mollusques (23%). L'indice biotique AMBI a montré que la région est en bon état écologique. Trois assemblages benthiques ont été identifiés par la classification ascendante hiérarchique et le positionnement multidimensionnel sur la base de leur spécificité faunistique, le type de sédiments et les contenus en matière organique

Lamellodiscus euzeti n. sp. (Monogenea : Diplectanidae), a parasite from Dentex canariensis and D. gibbosus (Teleostei : Sparidae)in the Atlantic Ocean and Mediterranean Sea

Lamellodiscus euzeti n. sp. (Monogenea: Diplectanidae) is described from the gills of two sparid fishes, Dentex canariensis (Steindachner) off Senegal and Ivory Coast and D. gibbosus (Rafinesque) off Senegal and Tunisia. The new species belongs to the “ignoratus” group, characterized by a lamellodisc with complete lamellae, a “lyre” shaped male copulatory organ type, and the “ignoratus” sensu stricto subgroup, characterized by a haptor with simple lateral dorsal bars. Lamellodiscus euzeti n. sp can be distinguished from all the congeneric species of the “ignoratus” subgroup by the presence of a prominent protuberance at the base of the curved part of the simple piece of the male copulatory organ (MCO), a large bulb at the base of the bifurcated piece of the MCO and the presence of 5-6 spines in the distal portion of the axial branch of the bifurcated piece of the MCO. Specificity and biogeography of Lamellodiscus species from sparid fishes are discussed

Lamellodiscus euzeti n. sp. (Monogenea: Diplectanidae), a parasite from Dentex canariensis and D. gibbosus (Teleostei: Sparidae) in the Atlantic Ocean and Mediterranean Sea

Lamellodiscus euzeti n. sp. (Monogenea: Diplectanidae) is described from the gills of two sparid fishes, Dentex canariensis (Steindachner) off Senegal and Ivory Coast and D. gibbosus (Rafinesque) off Senegal and Tunisia. The new species belongs to the “ignoratus” group, characterized by a lamellodisc with complete lamellae, a “lyre” shaped male copulatory organ type, and the “ignoratus” sensu stricto subgroup, characterized by a haptor with simple lateral dorsal bars. Lamellodiscus euzeti n. sp can be distinguished from all the congeneric species of the “ignoratus” subgroup by the presence of a prominent protuberance at the base of the curved part of the simple piece of the male copulatory organ (MCO), a large bulb at the base of the bifurcated piece of the MCO and the presence of 5-6 spines in the distal portion of the axial branch of the bifurcated piece of the MCO. Specificity and biogeography of Lamellodiscus species from sparid fishes are discussed

Ellipsometric investigation of porous silicon layers for the design of a DBR

Porous silicon layers (PSL) were fabricated by electrochemical etching and investigated by spectroscopic ellipsometry (SE) in the energy range 0.6−5 eV. Within the effective medium approximation (EMA) and through an optical model consisting of a mixture of void and crystalline silicon (cSi), we were able to determine the porosity (void concentration) and the thicknesses of the PSL. The PSL were divided into several sublayers in order to obtain the best agreement between measured and simulated spectra. Once the etching parameters have been controlled and by choosing the appropriate conditions, it was possible to design a distributed Bragg reflector (DBR) with a high reflectivity band centered at 800 nm. This DBR consists on stacks of alternate PSL having two different refractive indices