1,721,041 research outputs found
Feeding in Deep Waters: Temporal and Size-Related Plasticity in the Diet of the Slope Predator Fish Coelorinchus caelorhincus (Risso, 1810) in the Central Tyrrhenian Sea
No full textIn-depth studies on the effect of size and period in the diet of the hollow-snout grenadier Coelorinchus caelorhincus in the Mediterranean Sea are scant and incomplete. We obtained 75 specimens of this species from the discard of deep trawl fishing on the slope of the central Tyrrhenian Sea. As corollary data, we estimated the length–weight relationship, the size frequency distribution, and composition of sexual maturity stages of the sampled individuals. We deepened stomach content analysis aiming at the evaluation of size and period’s effect in the fish diet by Costello’s interpretation of dietary indexes and correspondence analysis. The corollary results suggested negative allometric growth (b = 2.69), an asynchronous reproductive strategy (paucity of mature individuals) and a size-related bathymetrical distribution for this species (prevalence of small and intermediate-sized specimens). The prey importance index (PII) revealed that the hollow-snout grenadier is a generalist feeder on cephalopods (PII: 0–1200), fish (PII: 0–1000), crustaceans (PII: 4000–6000), and polychaetes (PII: 400–1800), and a light specialist at population level on the dominant prey among them. At the micro-taxa level, the species was found to be a generalist feeder on 10 groups of rare prey and a light specialist at population level on amphipods (PII: 1300–3200). Overall, results indicated the presence of two feeding gradients that determined an intermingled effect of size and period on fish diet. In particular, intraspecific competition and stability of food resources appeared as the factors that significantly harmonize the diet of Coelorinchus caoelorhincus in the context of the ecotrophic constraints of a deep-sea species
New evidence of a fish–bird interspecific feeding association between the European seabass and the European shag in the Mediterranean Sea
No full textAlthough they have received little attention, interspecific feeding associations are a particular predation behavior in which two or more different species temporary feed simultaneously on the same food sources to obtain greater success in predation. These collaborations can be either mutualistic, commensalistic, or parasitic. One of the best-known examples is the seabird–cetacean associations. Prey herding is the foraging tactic most used in these associations and consists of swimming around and under prey balls to trap them in the water column. Here we reported some new evidence of a fish–bird interspecific feeding association between the European seabass, Dicentrarchus labrax (Linnaeus, 1758) and the European shag, Gulosus aristotelis (Linnaeus, 1761). We analyzed this association through the photograph and video documentation provided by “citizen scientists” in the Mediterranean Sea. We collected reliable proofs of this behavior, at least, in three instances from observations made by recreational fishermen in the Kvarner bay (Croatia, North Adriatic Sea). From the photographs and videos made available, we attempted to reconstruct a predation strategy adopted by these associated species to better understand the advantage this provides during hunting. Although it is not yet clear whether this association is an opportunistic behavior of the European seabass or a mutualistic strategy used by both species to improve their catching success, this feeding association seems to increase the chances to defeat prey defense strategies. Notably, some behavioral imitation of hunting strategies may be put in place by seabasses, which often feed in association with dolphins and other birds using similar prey herding strategies
The Sicily Island: an observatory to detect non-indigenous, vagrant and neglected species in the Mediterranean Sea
No full textSicily's central position in the Mediterranean Sea makes it a crossroad for marine species dispersal routes. This study, through data collected along the coast (sampling sites: Trapani, Palermo, Catania, Siracusa, Marzamemi, and Portopalo di Capo Passero),
confirms its strategic role in connecting sub-basins, for both native species and NIS, also favouring the detection of rare or neglected species. Surveys in this area could improve understanding of biodiversity changes, biological invasions, and rare and neglected marine species distribution
Trophoniella cucullata, a new flabelligerid species from Mediterranean Posidonia oceanica meadows (Annelida, Flabelligeridae)
No full textA new species belonging to the genus Trophoniella Hartman, 1959 (Polychaeta: Flabelligeridae) was described from the coastal area of Civitavecchia (Northern Tyrrhenian Sea). The species was collected in gravelly coarse sands from Posidonia oceanica beds at around 7 m depth. Trophoniella cucullata sp. nov. clearly differs from all other congeners species primarily by the distribution of the sediment grains on the body and by the starting point of the anchylosed neurohooks. Diagnostic morphological traits for the identification of the species are discussed. The description of Trophoniella cucullata sp. nov. in the same P. oceanica biocenosis where other species have been recently reported in the Northern Tyrrhenian Sea, testifies to the role of this marine phanerogam as a biodiversity hotspot
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
P21-38 Heavy metals in the blue crabs (Callinectes sapidus) collected in coastal lagoons and shallow marine waters of Northwestern Adriatic Sea
No full textPurpose: The Atlantic blue crab (Callinectes sapidus), endemic to the eastern coast of America, is listed among the worst invasive species
introduced into the Mediterranean. It was reported in the Emilia-Romagna region lagoons (Italy) in 2015 [1], and in very recent times it colonized all the Italian coastal areas [2]. This species poses threat to shellfish farming and biodiversity. A potential mitigation strategy is the increase of the fishing pressure, using this species as a food source for humans and animals. However, a risk for human health is the possibility of crabs accumulating pollutants, such as heavy metals (HMs). HMs are an important indicator of pollution, especially in the aquatic environment, due to their high toxicity and persistence, non-biodegradability, tendency to bioaccumulate in the trophic chain (biomagnification). The aim of this study was to evaluated the concentrations of 6 elements (lead, cadmium, chromium, mercury, nickel, arsenic) in the edible tissues of crabs collected along the Emilia Romagna coasts. Methods: From August 2023 to March 2024, 30 samples were collected. All crabs were separated by sex, measured (carapace width),
weighted and tissues pooled. An in-house triple quadrupole inductively coupled plasma mass spectrometry (TQ-ICP-MS) method was used
to analyze 30 pool (15 for each sex) (152 specimens) of muscle and 30 pool of hepatopancreas, after a wet mineralization process with concentrated
nitric acid. The method has been validated for detecting HMs in accordance with Regulation (EC) 333/2007 [3], with a limit of quantification
(LOQ) of 5 μg/kg. The results obtained by males and females were compared for the concentration of HMs. Results: HMs investigated in muscle tissues and hepatopancreas of male and female C. sapidus individuals were Pb, Hg, Cd, Ni, As, and Cr. No sex-related differences were observed for any metal. Preliminary results showed no tissue-related differences for metals such as Hg, Cr and As. For Pb, Cd and Ni, significant differences for the hepatopancreas and muscle tissue (p<0.001) were observed. Pb concentration in the hepatopancreas was threefold higher than in the muscle, with an average concentration of 0.061 mg/kg. Cd concentrations were several times higher in the hepatopancreas (1.67 mg/kg) and were lower in
muscle tissue (p<0.001). Ni concentrations were fivefold higher in thehepatopancreas (0.506 mg/kg) than in the muscle. The present study
is a preliminary evaluation of the concentration of heavy metals in C. sapidus sampled along the coasts of Emilia Romagna. The results have
shown that no significant differences are observed between male and female individuals. A different accumulation capacity of HMs in the
analyzed tissues was observed. In particular, significant accumulation of metals such as Pb, Cd and Ni was demonstrated in the hepatopancreas,
while low levels observed in the muscle.
References
[1] Manfrin, C., Chung, J., Turolla, E., & Giulianini, P. (2015). First occurrence of Callinectes sapidus (Rathbun, 1896) within the Sacca di Goro (Italy) and surroundings. Check List, 11(3), 1-4.
[2] Tiralongo, F., Villani, G., Arciprete, R., & Mancini, E. (2021). Filling the gap on Italian records of an invasive species: first records of the Blue Crab, Callinectes sapidus Rathbun, 1896 (Decapoda: Brachyura: Portunidae), in Latium and Campania (Tyrrhenian Sea). Acta Adriatica, 62(1), 99-104.
[3] Commission Regulation (EC) No 333/2007 of 28 March 2007 laying down the methods of sampling and analysis for the official control of the levels of lead, cadmium, mercury, inorganic tin, 3-MCPD and benzo(a)pyrene in foodstuffs (OJL 88, 29.3.2007, p. 29–38
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
First Record of Megamphopus katagani Bakir, Sezgin & Myers, 2011 (Amphipoda, Photidae) in the Italian Waters: A Species Associated with the “Amphioxus Sand” Biocenosis
No full textThe biocenosis of coarse sand and gravel exposed to bottom currents (SGCF) is the typical habitat of the amphioxus Branchiostoma lanceolatum (Pallas, 1774). This species and the habitat where it lives are threatened, and there are few reports of this biocenosis in the Italian and European waters. During a sampling survey carried out along the eastern Sicily coast (Ionian Sea) the macrozoobenthic community associated with this biocenosis was investigated. In this work, we report the presence of “Amphioxus sand” habitat in the Ionian Sicilian coast and the first record of the amphipod Megamphopus katagani Bakir, Sezgin and Myers, 2011 in the Italian waters
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