Search results for "Diplodu"
showing 7 items of 27 documents
Digestive Enzymes in Larvae and Juveniles of Farmed Sharpsnout Seabream (Diplodus puntazzo) (Cetti, 1777)
2011
The ontogenetic development and pattern of main digestive enzyme activities (proteases, carbohydrases and lipases) were investigated in farmed sharpsnout seabream Diplodus puntazzo larvae and juveniles, during the passage from the larval stage to adult (from 21 to 277 days after hatching - DAH). Larvae showed exponential growth, thus confirming that Rotifers and Artemia nauplii are suitable preys for early feeding of D. puntazzo larvae. Pepsin activity was low in the larvae, but it increased afterwards in relation with stomach development. In juveniles, levels of specific activity of trypsin, chymotrypsin and elastase were lower compared to that recorded in larvae. A decrease in the activit…
Characterization of mitotic chromosomes of four species of the genus Diplodus: Karyotypes and chromosomal nucleolar organizer region phenotypes
1996
Karyotypes have been described in four Mediterranean species of the genus Diplodus (Teleostei, Sparidae), D. vulgaris, D. puntazzo, D. sargus and D. annularis. Chromosomes were mainly acrocentric in all but D. vulgaris, where certain chromosome pairs were subtelocentric. A remarkable intraspecific heteromorphism in the number of NOR-bearing chromosomes along with a substantial interspecific variability in position of chromosomal Ag signals have been encountered. The presumed origin of multiple NOR-bearing chromosomes in Diplodus species and variation of the NOR location is discussed. ? 1996 The Fisheries Society of the British Isles
The effects of protection measures on fish assemblage in the Plemmirio marine reserve (Central Mediterranean Sea, Italy): A first assessment 5years a…
2013
This 2-year study was aimed to investigate the early effects of protection measures on fish assemblage in the Plemmirio marine reserve and to evaluate its level of enforcement. Sampling was carried out by means of underwater visual census techniques in four sampling sites within the reserve boundaries and eight outside the reserve. Results showed significant inside/outside differences in the multivariate abundance of fish assemblage. These results were confirmed and exemplified by significant univariate differences between locations for total abundance, Species Richness and diversity of the fish assemblage; values of these metrics were higher inside the reserve than outside. Small fish size…
Experiences of integrated mariculture in a southern Tyrrhenian area (Mediterranean Sea)
1999
To ascertain the potential for exploiting marine areas for mariculture, data on the cultivation of molluscs and fish in the open sea of the southern Tyrrhenian were collected from May 1994 to June 1995. The aims of this integrated study were to test simple breeding methods for molluscs and fish, to apply these to the practices employed by local fishermen and to experiment with the use of a cage system requiring a low level of investment. Crassostrea gigas (Thunberg) and Mytilus galloprovincialis (Lamarck) were cultivated on submerged long lines around cages used for cultivating Seriola dumerili (Risso) and Diplodus puntazzo (Cetti). S. dumerili specimens were placed in two cages and fed wit…
Relative role of fish vs. starfish predation in controlling sea urchin populations in Mediterranean rocky shores
2009
In the Mediterranean, fishing bans generally allow the recovery of populations of sea urchin predators, such as the seabreams Diplodus sargus and D. vulgaris, promoting the transformation of overgrazed communities into ones dominated by erect macroalgae. However, in the marine reserve on Ustica Island (SW Italy) the opposite trend has occurred in the upper infralittoral community, and urchin barrens formed after the cessation of fishing activities. We hypothesized that (1) the natural scarcity of the 2 seabream species leads to a low predation rate on sea urchins at Ustica, and (2) predation rate varies with depth, due to differences in the predator assemblages. Tethering experiments were c…
Parasites of Diplodus puntazzo in Western Mediterranean: Morphological, developmental and host-parasite relationships of monogeneans
2014
En España la acuicultura ha experimentado un gran crecimiento durante el pasado siglo, sin embargo, durante los últimos años se ha producido una disminución en la producción de las especies de cultivo más importantes, como la dorada, la lubina y el rodaballo (APROMAR, 2011). Esta situación ha supuesto la primera reducción en la producción de los últimos 25 años. Por este motivo, los productores españoles apuestan por la recuperación de la productividad y el aumento de la competitividad en el mercado y, para poder llevar a cabo estas mejoras, uno de los objetivos marcados es diversificar las especies cultivadas (APROMAR, 2011). En el Mediterráneo español, una de las especies candidatas para …