Search results for "Fish"

A new sustainable formulated feed based on discards from food industries for rearing the sea urchin Paracentrotus lividus (Lmk)

2019

During a 18‐week experiment in a sea‐based system, Paracentrotus lividus was fed with two formulations of a new sustainable feed whose main ingredients were food farming discards, mostly outermost lettuce leaves, in different percentage. Egg white was added as protein source and binder, and a little amount of commercial fish feed was added as lipid source. At the end of the experiment, a high survival rate (>80%) and an increase in test diameter (22%), total weight (130%), gonad weight (240%) and gonad index expressed as size‐adjusted gonad weight (288%) were recorded. Gonads achieved a good colour and high levels of essential and polyunsaturated fatty acids, hence representing a commerc…

Effects of fish farming waste to sedimentary and particulate organic matter in a southern Mediterranean area (Gulf of Castellammare, Sicily): a multi…

2004

Abstract Carbon and nitrogen stable isotope analysis was used to investigate the dispersion area of waste material coming from fish farming activities in the western Mediterranean. Tests were conducted to see if uneaten feed and faecal material isotopic signals, originating from fish farms, could be detected in particulate organic matter (POM) and sedimentary organic matter (SOM). The detectable dispersion distance (from under cages as far as 1000 m) of cage-derived organic material was also examined. To do this, carbon (δ13C) and nitrogen (δ15N) composition in POM and SOM collected around the cages, in some control areas and in the waste material, was measured. Mean POM δ13C was −22.9±0.2‰…

Seasonal changes in size, sex-ratio and body condition of the damselfishChromis chromisin the central Mediterranean Sea

2014

Chromis chromisis one of the most abundant fish species on the Mediterranean rocky shores. Acting as a by-pass of nutrients from the pelagic to the rocky littoral system, it plays an important role as a resource provider and has a relevant function in the community assemblage.Chromis chromishas many of the characteristics required of an indicator species (e.g. it is easy to recognize in the field, small sized, widespread and abundant). In this study we focused on individual size, sex-ratio and body condition in a damselfish population occurring in a central Mediterranean marine protected area. Fishing trials on a monthly basis (April–November) allowed us to assess seasonal changes in popula…

Inter-habitat connectivity in a tropical ecosystem (Gazi Bay, Kenya) as revealed by ichthyofauna

2010

Elasmobranch by-catch in pelagic pair trawl: a preliminary study from Adriatic Sea

2008

A multi-technique approach to study fish diversity associated with off-shore platforms.

2010

Comparison of fishery methods for the study of fish diversity associated with off-shore platforms.

2010

Using web-based information systems and stable isotopes analysis to investigate the trophic structure of a fish assemblage in a Mediterranean lagoon

2010

Fish diversity associated with gas platforms: Evaluation of two underwater visual census techniques

2007

Se estudiaron las comunidades ícticas asociadas con plataformas extractivas mediante dos técnicas de censos visuales submarinos: transectos y conteos de puntos móviles. Los datos se tomaron a cuatro profundidades en tres diferentes plataformas situadas en el Mar Jónico (Crotone, Italia). Se registraron un total de 25 especies de peces pertenecientes a 12 familias. Se observaron diferencias significativas entre ambos métodos de muestreo y las profundidades en cuanto a la estructura de la comunidad íctica, la riqueza de especies y la abundancia de peces. El promedio de peces registrado con el método de transectos siempre fue mayor que el registrado mediante puntos móviles, mientras que lo con…

Stable isotopes and trophic positions of littoral fishes from a Mediterranean Marine Protected Area

2008

Stable isotope analyses were employed to explore feeding and foraging habitats and trophic levels of littoral fishes in a western Mediterranean Marine Protected Area (Egadi Islands, Sicily, Italy). Carbon and nitrogen stable isotope ratios were measured in primary producers, invertebrates and fishes collected in December 2001 and January 2002. Fishes of the littoral region of the Egadi Islands had isotopic signatures that fell into a wider range for δ13C (about 6‰) than for δ15N (about 3‰). Carbon isotope ratios were consistent with a food web based on mixed sources and two trophic pathways leading to different fish species. Differences in the isotopic composition between islands were highe…