Saltwater aquaponics is a sustainable alternative system for food production. The success of this system largely depends on the selection of both fish and plant species, for which several features ...and criteria must be considered. This paper aims to identify the most suitable plant species for saltwater aquaponics by using a multi-criteria decision-making method also based on current literature. One simple model that contained one root criterion, four aggregated criteria, and four sub-criteria was created using DEXi software. The same model was evaluated considering two different salinity levels in the recirculating water: 10 (brackish water) and 35 (sea water) g L−1. The relevance of the model structure was evaluated by the sensitivity analysis, through the ‘plus/minus-1′ analysis. Our results suggest that Salicornia europaea L. and Portulaca oleracea L. were suitable species for saltwater aquaponics at 35 g L−1. Moreover, at 10 g L−1, the suitable candidates were: Salicornia bigelovii Torr, S. europaea L., Beta vulgaris ssp. maritima (L.) Arcang, Atriplex hortensis L., and P. oleracea L. The DEXi analysis resulted in being an easy and effective tool to select proper species in similar contexts. DEXi can help to identify the hotspots of production processes, according to our results. Since the selected species are wild edible species or minor crops, the availability of their seeds is one of the main constraints of their cultivation in saltwater aquaponics.
Benthic diatoms of the genus Cocconeis contain a specific apoptogenic activity. It triggers a fast destruction of the androgenic gland in the early post-larval life of the marine shrimp Hippolyte ...inermis, leading to the generation of small females. Previous in vitro investigations demonstrated that crude extracts of these diatoms specifically activate a dose-dependent apoptotic process in human cancer cells (BT20 breast carcinoma) but not in human normal lymphocytes. Here, a bioassay-guided fractionation has been performed to detect the apoptogenic compound(s). Various HPLC separation systems were needed to isolate the active fractions, since the apoptogenic metabolite is highly active, present in low amounts and is masked by abundant but non-active cellular compounds. The activity is due to at least two compounds characterized by different polarities, a hydrophilic and a lipophilic fraction. We purified the lipophilic fraction, which led to the characterization of an active sub-fraction containing a highly lipophilic compound, whose molecular structure has not yet been identified, but is under investigation. The results point to the possible medical uses of the active compound. Once the molecular structure has been identified, the study and modulation of apoptotic processes in various types of cells will be possible.
Producing food according to the sustainability and “circular economy” principles is considered a strategic goal by several world Institutions. Integrated Multi-Trophic Aquaculture (IMTA) responds to ...these criteria and stemming from it, the “Self-sufficient Integrated Multitrophic AquaPonic” (SIMTAP) aims to drastically reduce production inputs and waste outputs while maximizing the total food production. In order to succeed, proper selection of the most suitable fish, intermediate organisms and plant species to be grown in the system plays a fundamental role. To validate the SIMTAP concept and experimental prototype, the biological characteristics of fish and other species should be assessed taking into account their complementarity and adaptability to the physical and technical traits of the considered system.
This study aimed to identify the most suitable marine organisms for food production within the SIMTAP system and to create a decision model via the DEXi decision support system. Hence, in the present work a brief description of the SIMTAP concept, as well as the biological, zootechnical and commercial characteristics of several candidate fish species, are discussed. The criteria considered to address the species selection were: natural geo-distribution, domestication degree, environmental requirements, feeding regime, growth performances, and market value. The candidate species were: Sparus aurata, Dicentrarchus labrax, Mugil cephalus, Diplodus puntazzo, Seriola dumerili, Umbrina cirrosa, Argyrosomus regius, Psetta maxima, Acipenser spp., Solea spp., Octopus vulgaris. Finally, it seems that the DEXi approach increased the objectivity of the species selection process. Gilthead Sea Bream, European Sea Bass and Flathead Grey Mullet resulted to be the most suitable species for SIMTAP production.
•Selecting suitable fish species for marine/brackish water land based IMTA systems•Literature review of the most common aquaculture species in the Mediterranean area•Multi-criteria decision method (DEXi) to select the suitable species•The suitable species selected by DEXi are Sparus aurata and Dicentrarchus labrax•DEXi represents a comprehensive tool for species selection in aquaculture and IMTA
Sex reversal is a process observed in several marine organisms, including some lineages of caridean shrimps. We investigated the gonopore shape and size, to study the sex reversal using
Hippolyte ...inermis
as a model. A method was developed which can be applied to identify the sex in juveniles of
H. inermis
, especially, useful when the standard method of sex assessment is not applicable. The position and the shape of gonopores was recorded under a light macroscope. The sex of mature individuals was then determined by observing the presence/absence of the
appendix masculina
. In addition, analysis of ontogenetic changes of gonopores were performed to compare their morphology with other species of shrimps whose gonopore morphology was previously known. Female gonopores are located at the far proximo-medial end of the third pair of pereiopod coxae and distally they bear cup-shaped structures, whilst male gonopores are located at the far proximo-medial end of the fifth pair of pereiopod coxae and they have a simpler structure. The shape and structure of gonopores in
H. inermis
resembled that of other caridean decapods. Intersex individuals were never observed, although this species was demonstrated to be protandric. This observation confirmed previous assumptions indicating that the process of sex reversal is very fast in
H. inermis
and that it takes place within a single moult. The identification of sex based on the position and shape of gonopores is feasible in this species, and it provides helpful insights for studying sex reversal in small decapods.
Ocean acidification (OA) influences the production of volatile organic compounds (VOCs) by seagrass leaves and their associated epiphytes. We hypothesize that the perception of “odour” produced by ...seagrass leaf epiphytes will change with seawater acidification, affecting the behaviour of seagrass-associated invertebrates. To test this hypothesis, we collected epiphytes from leaves of Posidonia oceanica growing at two pH conditions (7.7 and 8.1) and identified the most abundant genera of diatoms. We tested the VOCs produced at pH 8.1 by the epiphytic communities in toto, as well as those produced by selected diatoms, on various invertebrates. A complex set of species-specific and concentration-dependent chemotactic reactions was recorded, according to the pH of seawater. In particular, VOCs produced by individual diatoms triggered contrasting reactions in invertebrates, depending on the pH. The perception of epiphyte VOCs is likely to vary due to alteration of species ability to perceive and/or interpret chemical cues as infochemicals or due to changes in the structure of VOCs themselves. Thus, OA alters the fine-tuned chemical cross-talks between seagrass epiphytes and associated invertebrates, with potential consequences for the structure of communities and food webs of seagrass ecosystems.
•First time evaluation of the effect of infochemicals produced at two pH by the epiphytic community and by selected diatoms.•O.A. alters the fine-tuned chemical cross-talks between seagrass epiphytes and associated invertebrates.•Algae play their roles at different concentrations and convey different messages to associated animal communities.•O.A. has consequences on the structure of associated communities and food webs of seagrass ecosystems.
Several plants and invertebrates interact and communicate by means of volatile organic compounds (VOCs). These compounds may play the role of infochemicals, being able to carry complex information to ...selected species, thus mediating inter- or intra-specific communications. Volatile organic compounds derived from the wounding of marine diatoms, for example, carry information for several benthic and planktonic invertebrates. Although the ecological importance of VOCs has been demonstrated, both in terrestrial plants and in marine microalgae, their role as infochemicals has not been demonstrated in seagrasses. In addition, benthic communities, even the most complex and resilient, as those associated to seagrass meadows, are affected by ocean acidification at various levels. Therefore, the acidification of oceans could produce interference in the way seagrass-associated invertebrates recognize and choose their specific environments. We simulated the wounding of Posidonia oceanica leaves collected at two sites (a control site at normal pH, and a naturally acidified site) off the Island of Ischia (Gulf of Naples, Italy). We extracted the VOCs and tested a set of 13 species of associated invertebrates for their specific chemotactic responses in order to determine if: a) seagrasses produce VOCs playing the role of infochemicals, and b) their effects can be altered by seawater pH. Our results indicate that several invertebrates recognize the odor of wounded P. oceanica leaves, especially those strictly associated to the leaf stratum of the seagrass. Their chemotactic reactions may be modulated by the seawater pH, thus impairing the chemical communications in seagrass-associated communities in acidified conditions. In fact, 54 % of the tested species exhibited a changed behavioral response in acidified waters (pH 7.7). Furthermore, the differences observed in the abundance of invertebrates, in natural vs. acidified field conditions, are in agreement with these behavioral changes. Therefore, leaf-produced infochemicals may influence the structure of P. oceanica epifaunal communities, and their effects can be regulated by seawater acidification.
Volatile organic compounds (VOCs) may play the role of infochemicals and trigger chemotaxis and ecologically relevant responses in freshwater and marine invertebrates. Aquatic grazers use these ...signals as chemical cues to trace the presence of their food or to detect their predators. However, detailed data are still needed to fully understand the role of these relationships in marine plankton. We investigated the ability of the copepod Centropages typicus to perceive the odour of three planktonic diatoms (Skeletonema marinoi, Pseudonitzschia delicatissima and Chaetoceros affinis) and a dinoflagellate (Prorocentrum minimum). This information is ecologically relevant for orientation, habitat selection, predator avoidance and communication. In addition, as the pH of the medium influences the perception of chemical cues in aquatic environments, we tested the effect of seawater acidification resulting from increasing levels of CO2, and its influences on the olfactory reactions of copepods. For this reason, our tests were repeated in normal (pH 8.10) and acidified (pH 7.76) seawater in order to simulate future ocean acidification scenarios. Using replicated chemokinetic assays we demonstrated that VOCs produced by Ps. delicatissima and Pr. minimum attract copepods at normal pH, but this effect is lowered in acidified water. By contrast, the odour of S. marinoi mainly induces a reaction of repulsion, but in acidified water and at higher concentrations this toxic diatom becomes attractive for copepods. Our experiments demonstrate, for the first time, that copepods are sensitive to the volatile compounds contained in various microalgae; VOCs prompt chemokinesis according to algal species and odour concentrations. However, seawater acidification induces changes in copepods' perception of odours. These findings highlight the sensitivity of chemically mediated interactions to global changes
Plants evolve the production of wound-activated compounds (WACs) to reduce grazing pressure. In addition, several plant-produced WACs are recognized by various invertebrates, playing the role of ...infochemicals. Due to co-evolutionary processes, some invertebrates recognize plant infochemicals and use them to identify possible prey, detect the presence of predators or identify algae containing various classes of toxic metabolites. Different metabolites present in the same algae can play the role of toxins, infochemicals or both simultaneously. We investigated the infochemical activity of compounds extracted from three diatoms epiphytes of the seagrass Posidonia oceanica, by conducting choice experiments on invertebrates living in the same community or in close proximity. Furthermore, the specific toxicity of the extracts obtained from the same algae was tested on sea urchin embryos using a standard bioassay procedure, to detect the presence of toxins. The comparison of the two effects demonstrated that invertebrates are subjected to diatom wound-activated toxicants when these algae are not associated with their own habitat, but they are able to recognize volatile infochemicals derived from diatoms associated with their habitats. The specific toxicity of WACs was shown to be inversely correlated to the perceptive ability of invertebrates towards volatile compounds liberated by the same algae. Hence, when the recognition of specific algae by a given invertebrate species evolves, their detrimental effects on the receiving organism may be lost.
Decapods are important in aquaculture practice and as models for marine biology research, due to peculiar endocrine and physiologic adaptations to various environments. For these reasons, decapods ...are cultivated. To promote their correct development and sexual maturation, the preparation of balanced diets is crucial. Several diets, both experimental and for aquaculture purposes, have been established, but the set of essential fatty acids is still unknown for most species. Furthermore, fatty acids contained in formulated feeds are differentially sensitive to decay over the storage time. Here we compare growth, maturation and mortality of post-larvae fed on a formulated diet containing Artemia sp., Spirulina sp. and a fatty acid integrator, as administered immediately after its production and after 12 months of storage. The same foods were analysed for their fatty acid contents using gas chromatography. The sets of fatty acids present in differently aged foods corresponded to differences in the growth rates and survival of the model organism Hippolyte inermis cultured in the laboratory. The differences were mainly due to seven fatty acids, whose abundance decreased during the storage, the most important of which were arachidonic and linolenic acid, that are known to be essential for other species of decapods.
The growing global need for antioxidative phenolics and flavonoids for maintenance of human health resulted into search of new sustainable unexplored medicinal plants used by the traditional healers ...for various ailments. Many synthetic based products of phenolics and flavonoids have been used, however the demand of eco-friendly, natural herbal based products are increasing. As a result, the current study aims to explore traditional potential of Polygonum posumbu related to its phenolics and flavonoids. Optimization of extraction parameters were employed which includes: solvent selection (water, ethanol, methanol, acetone and ethyl acetate), ethanol composition (40–100%), solvent to sample ratio (30–70 ml/g), temperature (50–80 °C) and time (1–5 h). Under optimal conditions, total phenolics (TPC), total flavonoids (TFC), the extract yield (EY) and antioxidant activities of leaves extract were 162.79 ± 2.28 mg GAE/g, 56.57 ± 6.22 mg QE/g 27.96 ± 0.91%, and 27.34 ± 0.98 μg/ml respectively. Seven flavonoids were quantified in different tissues with significant (p ≤ 0.05) differences found in flavonoids contents in different parts of the plant. Highest concentration of flavonoids was observed in stems: (−)-epicatechin-53.19 ± 1.13 mg/g, myricetin-15.90 ± 0.13 mg/g, quercetin-50.66 ± 0.08 mg/g, luteolin-43.10 ± 0.47 mg/g, apigenin-16.73 ± 0.43 mg/g. Leaves and roots had the highest amount of genistein (05.06 ± 0.01 mg/g) and kaempferol (11.13 ± 0.06 mg/g) respectively. From the study it had been found that Polygonum posumbu possess a very good amount of phenolics and flavonoids and this study details first ever investigation on this plant in terms of phenolics and flavonoids. Therefore, this study enhanced the importance of this bioresource in functional food or nutraceutical industries.
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•Extraction of phenolics and flavonoids from Polygonum posumbu's leaves is reported for the first time.•An optimal extraction condition was establishsed.•HPLC analysis identified and quantified seven flavonoid compounds.•Flavonoid compounds content were compared among three different tissues of the plant.•Stems showed the highest content of flavonoid compounds.
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