8 research outputs found

    New insights on the biological parameters of the exploited cuttlefish Sepia officinalis L. (Mollusca: Cephalopoda) in the northern Adriatic Sea in relation to the main fishing gears employed

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    The cuttlefish (Sepia officinalis Linnaeus 1758) represents one of the most important coastal fishery resources of the Mediterranean Sea. For Italy, 45% of cuttlefish landings (2,328 t) originates from coastal regions of the northern Adriatic Sea: Veneto, Marche, Emilia Romagna and Friuli Venezia Giulia. In terms of economic value this species represents about 8% (~€ 16.5 million) of the production from this basin. From May 2004 to October 2005, cuttlefish were purchased from commercial landings of the Grado fishery fleet. At least 30 specimens were randomly taken each month from each fishing method employed for this species: bottom trawl (cod end mesh size 40 mm), rapido trawl, trammel net (mesh size of inner panel 30 mm) and cuttlefish specific trap. The main biological aspects, such as size, sex ratio, reproductive stage and diet in relation to both the season and type of fishing gear were analyzed. 1,495 specimens, ranging from 3.5 to 18.0 cm mantle length, were analyzed. In relation to the observed size and reproductive stage of individuals caught, trammel nets and cuttlefish traps both appeared to target sexually mature individuals, whilst trawling gear were not selective for either recruits or spawners. In total 34 prey taxa were found in the stomachs of S. officinalis: crabs and bony fish species were the most important prey, although the latter appeared mostly in the largest specimens. Finally the fullness index revealed that cuttlefish caught by trawling were more suitable for diet analysis than those caught by static gear. In this way the contribution of the present paper was to give new insights on the biological parameters of this species in relation to the main fishing gears employed in the northern Adriatic Sea

    biodiversity feeding habits and reproductive strategies of benthic macrofauna in a protected area of the northern adriatic sea a three year study

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    The macrozoobenthic community at a sublittoral station located in the Marine Protected Area of Miramare, Gulf of Trieste (Italy) was investigated monthly from June 2002 to July 2005. Community variables were studied and related to food sources (particulate, total and biopolymeric carbon contents, benthic microalgae and meiofauna). In addition, the macrofaunal response to a heatwave that occurred in summer 2003 in the area was also explored. Univariate and multivariate analyses highlighted that the macrozoobenthic community structure shifted towards the end of the study. Diversity remained fairly stable throughout the study, despite the high turnover values. From a dominance of short-lived invertebrates related to irregular fresh organic matter inputs, the community shifted toward long-lived taxa, principally related to an increase of biopolymeric C and microalgal biomass. Semelparous invertebrates seem to be less resistant to high temperatures compared to iteroparous ones. The latter proved to be capable competitors since they prevailed over the semelparous species towards the end of the study.The community exhibited a certain degree of resistance to high temperature, due to the adaptation of the macrofaunal invertebrates to this particular stress, induced by the wide natural fluctuations in temperature that occur on a seasonal basis in the Gulf of Trieste. This study highlights the importance of long datasets to assess the state and ecological processes of the macrofaunal communities

    Record of an established population of Palaemon macrodactylus Rathbun, 1902 (Decapoda, Palaemonidae) in the Mediterranean Sea: confirming a prediction

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    The capture of larvae of Palaemon macrodactylus off Mallorca (Balearic Islands) has been recently reported as evidence of a potential presence of a population of this species in the Mediterranean Sea. Photos of this species, taken during dives in the Sacca di Goro (northern Adriatic) were published in the same year, but no specimen could be collected at that time. Herein we report the capture in 2013 of numerous individuals of the oriental shrimp, including ovigerous females, both in the Sacca di Goro and in the Lagoon of Marano and Grado (northern Adriatic Sea, Italy), confirming the existence of a well-established population of this species in the Mediterranean Sea.Peer reviewe

    Diet of the oilfish Ruvettus pretiosus (Perciformes: Gempylidae) in the Saint Peter and Saint Paul archipelago, Brazil

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    Feeding aspects of the oilfish, Ruvettus pretiosus, were studied based on 360 stomachs of both male and female specimens caught off the Saint Peter and Saint Paul Archipelago. The total length of the specimens ranged from 52.4 cm to 189.0 cm. Of the 360 stomachs examined, 135 presented some food and 225 were empty. Thirty-four taxa were identified, represented by 16 fish, 17 cephalopods and 1 crustacean. The stabilization of the food items richness was attained at 35 food items and 104 stomachs, approximately. A remarkable predation upon the flying fish Cheilopogon cyanopterus was observed around SPSPA, directly related to the main reproductive period of this species in the area. The oilfish's food spectrum shows that the species feeds on a wide vertical range in the water column, catching prey items at the surface or in shallow waters, as well as epi-mesopelagic fish, in addition to mesopelagic cephalopods.<br>Aspectos alimentares do peixe-prego, Ruvettus pretiosus, foram estudados com base nos estômagos de 360 espécimes, de ambos os sexos, capturados nos arredores do Arquipélago de São Pedro e São Paulo. Todos os exemplares foram capturados com linha de mão. O comprimento total dos exemplares variou de 52,4 cm a 189,0 cm. Dos 360 estômagos examinados, 135 apresentaram algum alimento e 225 estavam vazios. Trinta e quatro táxons foram identificados, representados por 16 peixes, 17 cefalópodes e um crustáceo. A estabilização da riqueza dos itens alimentares foi obtida com 35 itens e 104 estômagos. Uma predação notável sobre o peixe-voador Cheilopogon cyanopterus foi observada nas adjacências do ASPSP, diretamente relacionada com o principal período reprodutivo dessa espécie na área. O espectro alimentar do peixe-prego mostra que a espécie se alimenta em uma ampla faixa vertical na coluna d'agua, capturando desde presas de superfície ou águas rasas, a peixes epi-mesopelágicos, além de cefalópodes mesopelágicos
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