Gastric evacuation and feeding in the gilthead sea bream reared under semi-intensive conditions

Abstract

Gastric evacuation rates of the gilthead sea bream, Sparus aurata, fed with commercial pelleted food and polychaetes (Nereis diversicolor) were determined under experimental conditions. The estimated gastric evacuation rate for pelleted food was 7.97% h -1, with a total time of digestion of approximately 9 h. The respective values for the natural food were 6.24% h -1, with a total digestion time of approximately 12 h. The daily consumption of fish reared in earth ponds in a semi-intensive aquaculture facility was estimated through 24 h cycles performed between April and August. The daily consumption varied from 18.58 to 31.98 mg g-1. There was a constant increase in the average daily consumption per individual of 1.8-4.6 g (dry weight). During these cycles, samples of stomachs were taken and the contents preserved for further observation. The feeding behaviour of the reared fish was compared with a fish sample caught in the Ria Formosa lagoon. No common species were found between samples. A total of 38 prey were identified, which suggests that the gilthead sea bream is a non-specific predator. Despite the high abundance of natural prey in the ponds, the dependence of sea bream on pelleted food was high.

Lack of consistency between the trophic interrelationships of five sparid species in two adjacent central Mediterranean coastal lagoons

“…The food spectra characterized in the present study were in accordance with previous data on the same species (Froglia, 1977;Joubert & Hanekom, 1980;Rosecchi, 1987;Andrade et al, 1996;Sala & Ballesteros, 1997). Two species proved to be fairly specialized: D. puntazzo and L. mormyrus, the former feeding as a typical grazer on seagrass beds, the latter behaving as a strict soft bottom feeder.…”

“…Diplodus annularis and D. sargus were found to be generalist and remarkably omnivorous. Sparus aurata showed the most dramatic inter-lagoon diet differences, confirming it to be an euryphagous, non-selective benthic feeder (Andrade et al, 1996).…”

Gut evacuation rates in <i>Nephrops norvegicus</i> (L., 1758): laboratory and field estimates

“…This model is more appropriate for describing the evacuation of small, relatively easily digested particles from the stomach (Jobling, 1986), which is the case of Nephrops norvegicus. This approach has been widely use both in fish (Persson, 1986, Brodeur andPearcy, 1987;Andrade et al, 1996) and crustaceans (Hill, 1976;Sardá and Valladares, 1990 …”

“…The instantaneous evacuation rate has often been estimated for fish through laboratory experiments (Brodeur and Pearcy, 1987;Amundsen and Klemetsen, 1988;Parrish and Margraf, 1990;Andrade et al, 1996). Though this laboratory methodology has been widely applied to marine invertebrates such as copepods, amphipods or euphausids (Kiørboe and Tiselius, 1987;Clarke et al, 1988;Dam and Peterson,1988;Perissinotto and Pakhomov, 1996), there have only been a few attemps to apply this methodology to decapod crustaceans (Hill, 1976;Joll, 1982;Sardá and Valladares, 1990).…”

Μελέτη Της Σύστασης Κτηνοτροφικών Σπερμάτων Ψυχανθών Και Φύτρου Σπέρματος Χαρουπιού Και Της Επίδρασής Τους Στη Φυσιολογία Και Βιοχημεία Της Πέψης Μεσογειακών Ειδών Ιχθύων

“…Το μοντέλο αυτό δείχνει ότι η γαστρική εκκένωση είναι ταχύτερη αρχικά ενώ στη συνέχεια επιβραδύνεται καθώς μειώνεται η πληρότητα του στομάχου (Bromley, 1987, Persson, 1986, Riche et al, 2004. To εκθετικό μοντέλο έχει αναφερθεί ότι περιγράφει καλύτερα τον ΧΓΕ στην τσιπούρα που διατράφηκε με εμπορικό σιτηρέσιο σε μορφή συμπήκτων (Andrade et al, 1996).…”