Search results for "Systematic"
showing 10 items of 7608 documents
Stable carbon and nitrogen ratios in the sand smelt from a Mediterranean coastal area: Feeding habits and effect of season and size
2002
Enriched (δ13C values (annual average - 11·2%) suggest that in the study site (Stagnone di Marsala, Italy) the sand smelt Atherina boyeri exploited benthic prey throughout the year. In particular, Mysidacea and Isopoda seemed to dominate the diet. Stomach content data from the literature was in partial agreement with the present isotopic analysis suggesting that, while Mysidacea and Isopoda are exploited by A. boyeri, Copepoda Harpacticoida and Amphipoda are the dominant food items of the sand smelt diet. Several hypotheses are proposed to explain such partially different results from the two techniques. Both season and size influenced the δ13C and δ15N values of A. boyeri. Although through…
Mapping the potential for offshore aquaculture of salmonids in the Yellow Sea
2022
AbstractMariculture has been one of the fastest-growing global food production sectors over the past three decades. With the congestion of space and deterioration of the environment in coastal regions, offshore aquaculture has gained increasing attention. Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) are two important aquaculture species and contribute to 6.1% of world aquaculture production of finfish. In the present study, we established species distribution models (SDMs) to identify the potential areas for offshore aquaculture of these two cold-water fish species considering the mesoscale spatio-temporal thermal heterogeneity of the Yellow Sea. The values of the a…
Biological traits, geographic distributions, and species conservation in aquatic ecosystems
2022
Aquatic ecosystems (both marine and freshwater) have long served as model systems for exploring the role of environmental stressors on organismal performance and survival, the biogeographic distributions of populations and species, and ultimately the diversity, functioning, and stability of ecosystems (Adams, 2002; Forbes, 1887; MacArthur & Wilson, 2001; Paine, 1969; Somero et al., 2017 ). Climate change, alien species invasions, land use change, urbaniza-tion, and other anthropogenic impacts have all been demonstrated to impair aquatic ecosystems at multiple levels of biological orga-nization within aquatic ecosystems (Karr, 1991; Doney et al., 2012; Harley et al., 2006; Poloczanska et…
Dynamic Energy Budget model parameter estimation for the bivalve Mytilus californianus: Application of the covariation method
2014
Dynamic Energy Budget (DEB) models serve as a powerful tool for describing the flow of energy through organisms from assimilation of food to utilization for maintenance, growth and reproduction. The DEB theory has been successfully applied to several bivalve species to compare bioenergetic and physiological strategies for the utilization of energy. In particular, mussels within the Mytilus edulis complex (M. edulis, M. galloprovincialis, and M. trossulus) have been the focus of many studies due to their economic and ecological importance, and their worldwide distribution. However, DEB parameter values have never been estimated for Mytilus californianus, a species that is an ecological domin…
Effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus in the Mediterranean Sea
2007
The effect of boat noise on the behaviour of bluefin tuna Thunnus thynnus was investi- gated in the Egadi Islands, Sicily, during spring 2005 using a fixed tuna trap set near shipping routes. Tuna behaviour was observed when exposed to both natural ambient sound and sound generated by hydrofoil passenger ferries, small boats and large car ferries. Acoustical and behavioural analyses were conducted with and without extraneous sound to define a list of behavioural categories. Each vessel produced different engine sounds with regard to their composition and bandwidth, and all were distinctly different from ambient sound levels. In the absence of boat noise, tuna assumed a con- centrated coordi…
Dimethyl disulfide and dimethyl trisulfide: so similar yet so different in evoking biological responses in saprophilous flies
2014
Dimethyl disulfide (DMDS) and dimethyl trisulfide (DMTS) are used by saprophilous insects to locate breeding sites (decaying organic matter), and by brood-site deceptive flowers to attract such insects. However, little is known about the relative importance of these two compounds in eliciting electrophysiological and behavioral responses in the insects. Here, we compared the relative attractiveness of DMDS and DMTS to saprophilous flies in field choice experiments and tested whether potential differences in field responses can be explained by differences in electrophysiological antennal responses to these compounds. Field experiments revealed that the attractiveness of a mixture of these co…
Discriminating between Posidonia oceanica meadows and sand substratum using multibeam sonar
2010
Abstract Di Maida, G., Tomasello, A., Luzzu, F., Scannavino, A., Pirrotta, M., Orestano, C., and Calvo, S. 2011. Discriminating between Posidonia oceanica meadows and sand substratum using multibeam sonar. – ICES Journal of Marine Science, 68: 12–19. High-resolution, multibeam sonar (MBS) (455 kHz) was used to identify two typologies of seabed 8 m deep: Posidonia oceanica meadow and sandy substratum. The results showed that the heterogeneity of the architecture of the P. oceanica canopy and the relatively simple morphology of a sandy substratum can be detected easily by statistical indices such as standard deviation or range-of-beam depth. Based on these indices, an automated classification…
Electrophysiological and behavioural responses of the housefly to “sweet” volatiles of the flowers of Caralluma europaea (Guss.) N.E. Br.
2013
In sapromyiophilous plants, up to date, long range attraction of fly pollinators has been thoroughly investigated and attributed to ‘‘fetid’’ floral compounds, while the ‘‘sweet’’ floral scent fraction has not been spe- cifically investigated and its role has received little atten- tion. The aim of the present study was to verify if terpenoids, which are the main compounds of the floral bouquet of Caralluma europaea, play a role in the attrac- tion of its pollinator Musca domestica. Terpinolene, a- terpinene and linalool, described as the three main volatiles of the flowers of C. europaea, were evaluated in electro- physiological investigations and blends of these com- pounds as well as the…
Effect of the presence of the shore crab, Carcinus maenas, on the burrowing behaviour and clearance rate of the common cockle, Cerastoderma edule
2011
Bivalves demonstrate various morphological and behavioural adaptations to reduce the risk of being attacked by predators. This paper examines how the presence of the crab Carcinus maenas (L.), a natural predator of the cockle Cerastoderma edule (L.), affects its burrowing depth and clearance or feeding rate. Cockles were placed in experimental tanks and treated with three levels of predatory disturbance: (1) unfed crab loose inside the tank, (2) unfed crab inside a cage suspended in the water column and (3) no crab present. Cockles’ burrowing depth was measured in two sediment types: mud and sand. Cockles burrowed more deeply in treatments with no crabs. Burrowing depth in sand was signific…
Filtration pressure by bivalves affects the trophic conditions in Mediterranean shallow ecosystems
2009
Bivalve filtration may control the amount of seston in coastal waters, reducing local euthrophication and keeping degrading phenomena like hypoxia and anthropogenic pollution under control. Two Sicilian brackish-marine ponds (Ganzirri and Faro) present us with the opportunity to gain data on the effect of bivalve filtration on the amount of particulate organic matter in the field. The cultivation of bivalves has been carried out in both of the ponds since the early 1990s but stopped in Ganzirri in 1995.We tested whether the cessation of bivalve cultivation influenced features of organic matter available to suspension feeders (total suspended matter, its inorganic and organic fractions, chlo…