1SUMMARY In the last decades several changes have heavily impacted the Atlantic bluefin tuna fish... more 1SUMMARY In the last decades several changes have heavily impacted the Atlantic bluefin tuna fishery. To contribute to the evaluation of population status and the effectiveness of management policies, a long-term analysis of catch data (1993-2010) and standardized CPUE from the trap fishery of Sardinia (western Mediterranean, Italy) are presented. A significant increase is observed of the standardized CPUE together with a significant decrease of mean weight. The cluster analysis of the mean weight identified three different year groups: 1993-1995, 1996-2006 and 2007-2010. These time periods, which were confirmed by the analysis of the weight frequency distribution, have showed a progressive reduction of larger individuals in the landings. A significant increase of recruits was observed, beginning in 2007, together with a slight increase of mean weight. This trend, which needs to be confirmed over a larger time span of observations, might be the result of new management policies. Res...
Mediterranean giant red shrimp Aristaeomorpha foliacea (Risso, 1827) is one of the dominant speci... more Mediterranean giant red shrimp Aristaeomorpha foliacea (Risso, 1827) is one of the dominant species in deep-sea megafaunal assemblages, plays a key role in deep-sea communities and it is considered one of the most important targets of deep-water trawl fishing. Although a large number of studies have analysed the spatial distribution of epibenthic crustaceans in bathyal habitats with respect to environmental, geomorphological and hydrological factors, as well as fishing pressure, the manner in which these variables synergistically affect the spatio-temporal changes of giant red shrimp is unclear. To analyse the possible effects of abiotic predictors on the spatio-temporal distribution of giant red shrimp, Generalized Additived Models (GAMs) and Regression Trees were produced. Biological data were collected during the MEDITS trawl surveys carried out in the Sea of Sardinia (2009-2014), during which environmental data were obtained with a multiparametric probe. A longitudinal (west-eas...
The integration of sensory information with adequate motor outputs is critical for animal surviva... more The integration of sensory information with adequate motor outputs is critical for animal survival. Here, we present an innovative technique based on a non-invasive closed-circuit device consisting of a perfusion/stimulation chamber chronically applied on a single leg of the crayfish Procambarus clarkii. Using this technique, we focally stimulated the leg inside the chamber and studied the leg-dependent sensory-motor integration involving other sensory appendages, such as antennules and maxillipeds, which remain unstimulated outside the chamber. Results show that the stimulation of a single leg with chemicals, such as disaccharides, is sufficient to trigger a complex search behaviour involving locomotion coupled with the reflex activation of antennules and maxillipeds. This technique can be easily adapted to other decapods and/or other sensory appendages. Thus, it has opened possibilities for studying sensory-motor integration evoked by leg stimulation in whole aquatic animals under...
Pheromone-driven sex recognition has been widely documented in crayfish and a great deal of evide... more Pheromone-driven sex recognition has been widely documented in crayfish and a great deal of evidence supports the involvement of pheromones in their mating behaviour. This study investigates whether sexual interaction and mating success in the red swamp crayfish Procambarus clarkii are dependent on short-distance chemical communication between sexes, mediated by urine-borne pheromones. We compared the mating behaviour of intact animals that could release urine to chemically communicate in a natural way with that of urine-blocked animal pairs, for which chemical communication was precluded. Our results show that urine-borne pheromones are not critical for the reproductive success of P. clarkii, at least over the short-range distance (<1 m) considered in this study, during which the animals were confined in a restricted tank, facing one each other, and thus able to promptly mate. Under these experimental conditions, a lack of urine release neither precluded the occurrence, nor affe...
In this work we present an innovative application method for collecting data during the bottom tr... more In this work we present an innovative application method for collecting data during the bottom trawling using a multi-parameter probe. It regards the collection of both vertical and longitudinal profiles on the bottom during the fishing operations (while the net is fishing), in order to identify the main features of water masses. This information is useful to understand the variability of current data in relation to the catches. Introduzione -Durante gli ultimi venti anni le caratteristiche della circolazione marina e delle masse d'acqua nel mar Mediterraneo sono state ampiamente studiate attraverso l'utilizzo di modelli numerici che si basano su osservazioni di tipo oceanografico (e.g. Astraldi e Gasparini 1994; Millot, 1999). Grazie agli sforzi effettuati in questa direzione, si dispone oggi di un'ottima conoscenza della circolazione climatologica del bacino e della distribuzione delle masse d'acqua principali (MEDATLAS 132 Group, 2002). Ciò nonostante, i dati racc...
An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brack... more An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brackish water lagoon in southern Sardinia (western Mediterranean), resulted in the identification of 69 helminth parasite taxa and/or species from 13 fish species (n= 515) and seven bivalve species (n= 2322) examined between September 2001 and July 2011. The list summarizes information on the helminth parasites harboured by fish and molluscs contained in the available literature. Digenea species (37), both adults and larvae, dominated the parasite fauna, whereas Cestoda were the least represented class (three species). Monogenea, Nematoda and Acanthocephala were present with 17, 6 and 6 species, respectively, which were mainly adults. The most widespread parasite species was the generalist Contracaecum rudolphii A (Nematoda). Other species, such as the Haploporidae and Ascocotyle (Phagicola) spp. 1 and 2 (Digenea), showed a high family specificity in Mugilidae. Importantly, the study recorde...
Fish samples were collected between 1999 and 2002 in the Cabras lagoon, the largest brackish area... more Fish samples were collected between 1999 and 2002 in the Cabras lagoon, the largest brackish area in Sardinia and one of the most important areas for the artisanal lagoon fishery in the Mediterranean area. Because of its natural connection with both the Oristano ...
1SUMMARY In the last decades several changes have heavily impacted the Atlantic bluefin tuna fish... more 1SUMMARY In the last decades several changes have heavily impacted the Atlantic bluefin tuna fishery. To contribute to the evaluation of population status and the effectiveness of management policies, a long-term analysis of catch data (1993-2010) and standardized CPUE from the trap fishery of Sardinia (western Mediterranean, Italy) are presented. A significant increase is observed of the standardized CPUE together with a significant decrease of mean weight. The cluster analysis of the mean weight identified three different year groups: 1993-1995, 1996-2006 and 2007-2010. These time periods, which were confirmed by the analysis of the weight frequency distribution, have showed a progressive reduction of larger individuals in the landings. A significant increase of recruits was observed, beginning in 2007, together with a slight increase of mean weight. This trend, which needs to be confirmed over a larger time span of observations, might be the result of new management policies. Res...
Mediterranean giant red shrimp Aristaeomorpha foliacea (Risso, 1827) is one of the dominant speci... more Mediterranean giant red shrimp Aristaeomorpha foliacea (Risso, 1827) is one of the dominant species in deep-sea megafaunal assemblages, plays a key role in deep-sea communities and it is considered one of the most important targets of deep-water trawl fishing. Although a large number of studies have analysed the spatial distribution of epibenthic crustaceans in bathyal habitats with respect to environmental, geomorphological and hydrological factors, as well as fishing pressure, the manner in which these variables synergistically affect the spatio-temporal changes of giant red shrimp is unclear. To analyse the possible effects of abiotic predictors on the spatio-temporal distribution of giant red shrimp, Generalized Additived Models (GAMs) and Regression Trees were produced. Biological data were collected during the MEDITS trawl surveys carried out in the Sea of Sardinia (2009-2014), during which environmental data were obtained with a multiparametric probe. A longitudinal (west-eas...
The integration of sensory information with adequate motor outputs is critical for animal surviva... more The integration of sensory information with adequate motor outputs is critical for animal survival. Here, we present an innovative technique based on a non-invasive closed-circuit device consisting of a perfusion/stimulation chamber chronically applied on a single leg of the crayfish Procambarus clarkii. Using this technique, we focally stimulated the leg inside the chamber and studied the leg-dependent sensory-motor integration involving other sensory appendages, such as antennules and maxillipeds, which remain unstimulated outside the chamber. Results show that the stimulation of a single leg with chemicals, such as disaccharides, is sufficient to trigger a complex search behaviour involving locomotion coupled with the reflex activation of antennules and maxillipeds. This technique can be easily adapted to other decapods and/or other sensory appendages. Thus, it has opened possibilities for studying sensory-motor integration evoked by leg stimulation in whole aquatic animals under...
Pheromone-driven sex recognition has been widely documented in crayfish and a great deal of evide... more Pheromone-driven sex recognition has been widely documented in crayfish and a great deal of evidence supports the involvement of pheromones in their mating behaviour. This study investigates whether sexual interaction and mating success in the red swamp crayfish Procambarus clarkii are dependent on short-distance chemical communication between sexes, mediated by urine-borne pheromones. We compared the mating behaviour of intact animals that could release urine to chemically communicate in a natural way with that of urine-blocked animal pairs, for which chemical communication was precluded. Our results show that urine-borne pheromones are not critical for the reproductive success of P. clarkii, at least over the short-range distance (<1 m) considered in this study, during which the animals were confined in a restricted tank, facing one each other, and thus able to promptly mate. Under these experimental conditions, a lack of urine release neither precluded the occurrence, nor affe...
In this work we present an innovative application method for collecting data during the bottom tr... more In this work we present an innovative application method for collecting data during the bottom trawling using a multi-parameter probe. It regards the collection of both vertical and longitudinal profiles on the bottom during the fishing operations (while the net is fishing), in order to identify the main features of water masses. This information is useful to understand the variability of current data in relation to the catches. Introduzione -Durante gli ultimi venti anni le caratteristiche della circolazione marina e delle masse d'acqua nel mar Mediterraneo sono state ampiamente studiate attraverso l'utilizzo di modelli numerici che si basano su osservazioni di tipo oceanografico (e.g. Astraldi e Gasparini 1994; Millot, 1999). Grazie agli sforzi effettuati in questa direzione, si dispone oggi di un'ottima conoscenza della circolazione climatologica del bacino e della distribuzione delle masse d'acqua principali (MEDATLAS 132 Group, 2002). Ciò nonostante, i dati racc...
An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brack... more An extensive survey of helminth parasites in fish and shellfish species from Santa Gilla, a brackish water lagoon in southern Sardinia (western Mediterranean), resulted in the identification of 69 helminth parasite taxa and/or species from 13 fish species (n= 515) and seven bivalve species (n= 2322) examined between September 2001 and July 2011. The list summarizes information on the helminth parasites harboured by fish and molluscs contained in the available literature. Digenea species (37), both adults and larvae, dominated the parasite fauna, whereas Cestoda were the least represented class (three species). Monogenea, Nematoda and Acanthocephala were present with 17, 6 and 6 species, respectively, which were mainly adults. The most widespread parasite species was the generalist Contracaecum rudolphii A (Nematoda). Other species, such as the Haploporidae and Ascocotyle (Phagicola) spp. 1 and 2 (Digenea), showed a high family specificity in Mugilidae. Importantly, the study recorde...
Fish samples were collected between 1999 and 2002 in the Cabras lagoon, the largest brackish area... more Fish samples were collected between 1999 and 2002 in the Cabras lagoon, the largest brackish area in Sardinia and one of the most important areas for the artisanal lagoon fishery in the Mediterranean area. Because of its natural connection with both the Oristano ...
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