62 research outputs found
Temporal and Spatial Variations of Geodia cydonium (Jameson) (Porifera, Demospongiae) in the Mediterranean Confined Environments
Confined marine environments are particularly susceptible to climate change and anthropic pressures. Indeed, the long-term monitoring of benthic assemblages in these environments allows us to understand the direction of changes over time. The demosponge Geodia cydonium is a suitable study case, since it is widely represented in many Mediterranean environments, while being a long-living and important habitat-forming species. Here, we report the results of a descriptive study on temporal and spatial variations of this demosponge in three semi-enclosed environments along the Italian coast: Marsala Lagoon, Porto Cesareo Bay, and Mar Piccolo of Taranto. At Marsala and Porto Cesareo, the study compares the present data with those reported by the literature at the end of the 1990s. Caused by the modification of its preferential habitats, the data indicated the loss and a remarkable regression of this species at Porto Cesareo and Marsala, respectively. In addition, we hypothesized that the increase in severe weather phenomena in the small Bay of Porto Cesareo recorded during the last 20 years may have had a marked impact on water mass, thus affecting the sponge assemblages. At Taranto, despite a remarkable environmental degradation, G. cydonium has appeared stable and persistent in the last 45 years, thus representing one of the richest and most well-preserved populations in the Mediterranean Sea
Aquaculture and Restoration: Perspectives from Mediterranean Sea Experiences
In this paper, the different possibilities and innovations related to sustainable aquaculture
in the Mediterranean area are discussed, while different maricultural methods, and the role of
Integrated Multi-Trophic Aquaculture (IMTA) in supporting the exploitation of the ocean’s resources,
are also reviewed. IMTA, and mariculture in general, when carefully planned, can be suitable
for environmental restoration and conservation purposes. Aquaculture, especially mariculture, is
a sector that is progressively increasing in parallel with the increase in human needs; however,
several problems still affect its development, mainly in relation to the choice of suitable sites, fodder
production, and the impact on the surrounding environment. A current challenge that requires
suitable solutions is the implementation of IMTA. Unfortunately, some criticisms still affect this
approach, mostly concerning the commercialization of new products such as invertebrates and
seaweeds, notwithstanding their environmentally friendly character. Regarding the location of a
suitable site, mariculture plans are currently displaced from inshore to offshore, with the aim of
reducing the competition for space with other human activities carried out within coastal waters.
Moreover, in open water, waste loading does not appear to be a problem, but high-energy waters
increase maintenance costs. Some suggestions are given for developing sustainable mariculture in
the Mediterranean area, where IMTA is in its infancy and where the scarce nutrients that characterize
offshore waters are not suitable for the farming of both filter feeder invertebrates and macroalgae.
From the perspective of coupling mariculture activity with restoration ecology, the practices suggested
in this review concern the implementation of inshore IMTA, creating artificially controlled gardens, as
well as offshore mussel farming coupled with artificial reefs, while also hypothesizing the possibility
of the use of artificially eutrophized areas
The physiological response of the white-rot fungus, Schizophyllum commune to Trichoderma viride, during interspecific mycelial combat
Fungal species compete for space and nutrients in organic matter, resulting in strong morphological and biochemical reactions in the interacting mycelia. Interspecific mycelial interactions have attracted extensive studies because of their potential applications in biological control, bio-pulping, screening for novel bioactive metabolites and enhancement of extracellular enzyme production. Studies of interspecific mycelial combat have also contributed to the understanding of the structure and development of fungal communities. Although the behaviour of interacting mycelia has been understood, mainly at the morphological level, the biochemical aspects have yet to be fully elucidated. The main aim of this study was to endeavour to understand the underlying cellular and molecular response patterns and adaptations of the white-rot fungus, Schizophyllum commune to a highly antagonistic strain of Trichoderma viride, by correlating the expression patterns of metabolites, proteins and selected genes of Schizophyllum commune in response to the antagonist. The study also investigated the implication of oxidative damage in these response patterns. Microscopic examination of stained and unstained mycelia of S. commune confronted by the mycelia of T. viride, revealed cell wall lysis, protoplasmic degeneration, hyphal expansion and subsequent hyphal disintegration, hence, cell death in the mycelia of S. commune, after 7 days of mycelial contact. Metabolite patterns of both species near the interaction zone were profiled by HPLC and GC/MS, in comparison to their self-paired mycelia. Sugar alcohols, phenolic compounds and organic acids were up-regulated in the interacting mycelia of both species, while �-aminobutyric acid, myo-inositol phosphate, pyridoxine and N-acetylglucosamine, were up-regulated in S. commune mycelia with a concurrent decrease in the levels of fatty acids detected in the latter. Expression patterns of selected genes of S. commune confronted by T. viride were investigated by RT-PCR, relative to patterns in its self-paired cultures. Genes encoding proteins involved in the synthesis of cell wall polymers, protein synthesis and protein quality control, signalling, and stress response were up-regulated. On the other hand, genes that code for proteins associated with glycolysis, nitrogen assimilation, membrane transport, mitochondrial ATP-synthetic machinery, and cellular multiplication/growth were down-regulated. Changes in protein expression were profiled in the mycelia of both species paired against each other using 2- Dimensional gel electrophoresis, and differentially expressed proteins were identified by MALDI-TOF-MS/MS, following peptide fragmentation. Proteins involved in protein synthesis and assembly, unfolded protein response, response to cellular injury, synthesis of phenolic compounds, recycling of carbon and nitrogen were up-regulated in the confronted mycelial domain of S. commune. Proteins involved in glycolysis and heat shock response were predominantly down-regulated in the mycelia of S. commune paired against T. viride. Proteins associated with antagonism, cellular metabolism, glycolysis, and ATP generation and protein synthesis were up-regulated in the mycelia of T. viride interacting with S. commune with a decline in the detected levels of proteins involved in cytoskeleton organisation. Biochemical assays revealed increases in the activity levels of antioxidant enzymes, superoxide dismutase, catalase, succinic semialdehyde dehydrogenase, glucose-6-phosphate dehydrogenase and in the levels of indicators of oxidative stress and secondary metabolism, such as lipid peroxidation, protein carbonylation, superoxide anion and phenolic levels in the mycelia of S. commune paired against T. viride. Similarly, the activities and protein levels of phenol-oxidising enzymes, namely laccase and manganese peroxidase increased in the confronted mycelial domain of S. commune. Chitinase activity increased in mixed liquid cultures of both fungi. Protein, and gene expression patterns, in the confronted mycelia of S. commune suggest an increase in the flux through the protein synthetic machinery, possibly resulting in endoplasmic reticulum stress, which may have activated the unfolded protein response. These are strong indications of oxidative stress induction and switch of mycelial growth to secondary metabolism. There was little evidence of antagonism by S. commune towards T. viride, suggesting that the patterns reported herein, may be a response rather than an attack mechanism towards the latter.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Esponjas de los lechos de rodolitos del área marina protegida de la isla de Ustica (sur del mar Tirreno), con un inventario completo de la espongofauna de la isla
The sponge fauna colonizing rhodolith beds from Ustica Island marine protected area was studied. Moreover, an inventory of the sponge species present along the island’s coasts was carried out for the first time. Analysis of rhodoliths trapped in nets used by local fishermen at two sites and data obtained from underwater video images were used to identify 25 sponge taxa, 22 of them at species level. The classes Demospongiae and Homoscleromorpha were present with 24 and 1 species, respectively. Most of the specimens were small-sized and represented by thick crusts or short erect branches. Few specimens were insinuating or excavating. Furthermore, qualitative sampling was performed on Ustica’s coralligenous formations, photophilous hard substrates and in marine caves, and the results obtained were added to the literature data. The overall checklist of sponges from Ustica encompassed 97 taxa, 90 named at species level, subdivided into 6 taxa of Calcarea, 3 of Homoscleromorpha and 88 of Demospongiae. Eleven of the species were endemic to the Mediterranean Sea, mainly concentrated on rhodoliths and in marine caves. This research adds a fundamental element to the knowledge of invertebrates associated with rhodoliths, and updates the checklist of sponges colonizing Ustica’s waters, facilitating its future monitoring.En este trabajo se estudió la fauna de poríferos que coloniza los fondos de rodolitos del área marina protegida de la isla de Ustica. Además, se creó por primera vez un catálogo de las especies de esponjas que se encuentran en el litoral de la isla. El análisis de los rodolitos enredados en las redes de pescadores locales en dos sitios y de los datos obtenidos de las imágenes de video submarino permitieron reconocer 25 taxones de poríferos, 22 de los cuales se identificaron a nivel de especies. Las clases Demospongiae y Homoscleromorpha estuvieron presentes con 24 y 1 especies respectivamente. La mayoría de los especímenes eran de tamaño pequeño y representados por costras gruesas o ramas cortas y erectas. Pocos especímenes eran esponjas insinuantes o excavadoras. Además, se llevaron a cabo muestreos cualitativos en formaciones de coralígeno, en sustratos duros fotofilos y en cuevas marinas de la isla de Ustica, y se añadieron los resultados obtenidos a los datos de la literatura. El inventario total de las esponjas de Ustica incluye 97 taxones, 90 nombrados a nivel de especies, divididos en: 6 taxones de Calcarea, 3 de Homoscleromorpha, 88 de Demospongiae. Once de las especies son endémicas del mar Mediterráneo, concentradas principalmente en fondos de rodolitos y dentro de cuevas marinas. Esta investigación añade un aspecto fundamental al conocimiento de la distribución de los poríferos, en particular los asociados con los rodolitos, y actualiza la lista de esponjas que colonizan los fondos de Ustica, proporcionando herramientas para su monitoreo futuro
Biofouling Role in Mariculture Environment Restoration: An Example in the Mar Grande of Taranto (Mediterranean Sea)
none7The biodiversity of macrobenthic invertebrates of two artificial hard substrates close
to a mariculture plant was assessed in order to understand the effect on the fouling
community of an innovative Integrated Multi-Trophic Aquaculture (IMTA) system. The
examined hard substrates were (i) vertical bare collectors that are placed around
the cages as new colonizable substrates, which were investigated from the early
colonization and (ii) artificial hard substrates already present under the cages analyzed
over time to observe changes due to the action on the water column by filter
feeder organisms colonizing the above vertical collectors. Overall, 186 taxa were
collected (both the substrates), of which 99 as sessile habitat-former or structuring
macroinvertebrates and 87 as associated fauna, mostly vagile forms. On the vertical
collectors 121 taxa were collected, among which 44 sessile structuring species and 77
vagile-associated taxa; on the artificial hard substrates under the cages, 124 taxa were
identified, 95 belong to the first category and 29 as associated taxa. The two analyzed
substrates shared 43% of sessile species (40) and 22% of associated species (19). At
the end of the first year of experimentation, the study revealed Sabella spallanzanii and
mussels as the most abundant taxa. Lastly, the communities under the cages showed
an increase in biodiversity after the placement of collectors. The changes were attributed
to the decrease in particulate matter originating as wastes from the breeding cage, which
was intercepted by the filter feeder community developed on the vertical collectors.openDaniele Arduini, Jacopo Borghese, Maria Flavia Gravina, Roberta Trani, Caterina Longo, Cataldo Pierri, Adriana GiangrandeArduini, Daniele; Borghese, Jacopo; Flavia Gravina, Maria; Trani, Roberta; Longo, Caterina; Pierri, Cataldo; Giangrande, Adrian
Site fidelity of Hippocampus guttulatus Cuvier, 1829 at Mar Piccolo of Taranto (Southern Italy; Ionian Sea)
AbstractLack of detailed knowledge on ecological niche, life cycles, spatial distribution, reproductive biology and space use strongly affects the selection of useful tools and measures in the conservation of threatened marine species. Especially for sedentary and slow species, behaviour and movement capacities are supposed to be the most important functional traits. Indeed, behavioural variability concerning available space and the close presence of individuals is considered a crucial trait for the population dynamics assessments, especially when disturbances of various causes are present in the environment. The present study aimed to investigate the site fidelity and degree of movement of Hippocampus guttulatus, an emblematic and threatened Mediterranean seahorse species. With this aim, a number of seahorses were tagged and monitored throughout two years within a limited area of the lagoon of Mar Piccolo of Taranto (Southern Italy). The studied individuals were initially morphometrically measured for size, sex and life-cycle stage and subsequently monitored through repeated four-month surveys each year. Obtained results indicated high site fidelity regardless of habitat type. Movement pattern was in line with the data on congeneric species, although values were slightly higher. The analyses showed differences in movement degree among different sexes and life-cycle stages and indicated greater mobility of adult females compared to males and juveniles. The investigated parameters showed a great variability suggesting that even small-scale environmental factors can influence the species mobility. Finally, a change in the population structure has been observed, with the loss of large individuals in 2016 and reduced recruitment in 2017. These findings indicated the possible presence of stressors that could lead to the alteration of the seahorse population at Mar Piccolo of Taranto
Consequences of the experimental removal of Sabella spallanzanii (Gmelin, 1791) from the fouling assemblage of a Mediterranean harbour
Filter feeding invertebrates are a relevant component of fouling assemblages with a pivotal role in ecological processes, since they improve water quality, enhance habitat heterogeneity and transfer organic matter from the water column to the benthos. They modulate the availability of resources to other species, with effects on the density and behavior of the surrounding macrofauna. The fanworm Sabella spallanzanii, one of the largest and most abundant Mediterranean filter feeders, provides a shelter for predation and a secondary substrate for algae and settlement for sessile invertebrates. We tested its role in driving the structure of fouling assemblages, through a removal experiment.The experiment was one-year-long, with four sampling times. The effect of the removal on the fouling community was marginal in terms of species richness and evenness, while the biomass showed important differences, with a constant increase over time with higher values in the samples containing S. spallanzanii. At the end of observations, the biomass reached the value of 3917 g DW m-2 in controls and 2073 g DW m-2 in treatments. The empty space left by fanworms was not used by other species with similar biomasses. It is possible that the functioning of fouling communities may, in the event of loss of species, fluctuate in terms of biomass mobilization to different compartments, either towards the pelagic compartment or to the detritus chain. In systems with reduced water turnover, this by-pass can have important consequences in terms of stability and ecological balance
First description of early developmental stages of the native invasive fireworm Hermodice carunculata (Annelida, Amphinomidae): a cue to the warming of the Mediterranean Sea
Observations on the reproductive behavior and larval development of the bristled fireworm Hermodice carunculata, a common inhabitant of shallow marine rocky bottoms in the Southern Mediterranean Sea, are reported here. In recent years, an increase in abundance and a northward expansion of the populations along the Southern Italian coast were jointly detected, presumably linked to rising water temperature in the Mediterranean Sea. After making in situ observations on two consecutive spawning events, live worms and fresh spawn were brought into the lab, kept at either 27 ºC or 22 ºC and followed through development. Complete and normal development was observed only at 27°C. By contrast, embryonic and larval development appeared to be slowed down at 22°C, stopping at the protrochophora stage. Early development of H. carunculata suggests the existence of a long pre-metamorphic, planktotrophic period in the water column that can explain the genetic cohesion of this species and the low genetic divergence found among populations across the Atlantic Ocean. The observed increase in abundance, invasiveness potential, and geographical northern distribution of the bearded fireworms is probably determined by a progressive northward latitudinal shift of the sea surface temperature coincident with the temperature threshold required for the developmental and reproductive success of the worm
An Innovative IMTA System: Polychaetes, Sponges and Macroalgae Co-Cultured in a Southern Italian In-Shore Mariculture Plant (Ionian Sea)
In this paper, we report data from the first year of rearing of a set of filter feeder
bioremediator organisms: macrobenthic invertebrates (sabellid polychaetes and sponges), coupled
with macroalgae, realized in a mariculture fish farm. This innovative integrated multi-trophic
aquaculture (IMTA) system was realized at a preindustrial level in the Gulf of Taranto (southern
Italy, northern Ionian Sea), within the framework of the EU Remedia Life project. Long lines
containing different collector typologies were placed around the fish breeding cages. Vertical
collectors were utilized for both polychaetes and sponges, whilst macroalgae were cultivated in
horizontal collectors. Data on the growth and mortality of the target species after the first year of
rearing and cultivation are given together with their biomass estimation. Polychaete biomass was
obtained from natural settlement on ropes previously hung in the system, while sponges and
macroalgae were derived from explants and/or inocules inserted in the collectors. The description
of the successional pattern occurring on collectors used for settling until reaching a “stable” point is
also described, with indications of additional filter feeder macroinvertebrates other than
polychaetes and sponges that are easily obtainable and useful in the system as bioremediators as
well. The results demonstrate an easy, natural obtaining of large biomass of sabellid polychaetes
settling especially from about a 4 to 10 m depth. Sponges and macroalgae need to be periodically
cleaned from the fouling covering. The macroalgae cycle was different from that of invertebrates
and requires the cultivation of two different species with about a 6-month cycle for each one. The
present study represents one of the first attempts at IMTA in the Mediterranean area where
invertebrates and macroalgae are co-cultured in an inshore fish farm. Possible utilization of the
produced biomass is also suggested
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