Acronym GRANDI PELAGICI
Category
Aquaculture
Title Acquicoltura responsabile di nuove specie ittiche: consolidamento e ampliamento delle conoscenze per il trasferimento tecnologico. Supporto scientifico per la riproduzione controllata di grandi pelagici: Seriola dumerilii e Thunnus thynnus - Responsible aquaculture of new fish species. Consolidation and expansion of knowledge for technology transfer. Scientific support to controlled reproduction of blue fin tuna Thunnus thynnus and greater amberjack Seriola dumerilii Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Giovanna Marino Coordinator email giovanna.marino@isprambiente.it
Coordinator institution
ISPRA - Italian National Institute for Environmental Protection and Research (Italy)
Institutions involved
NA
Start year 2003 End year 2005 Funding (€) € NA Website NA Summary This project aimed to set up controlled reproduction techniques for new finfish species candidate to aquaculture diversification in Mediterranean area. Two species were under investigation: bluefin tuna Thunnus thynnus e greater amberjack Seriola dumerilii. Greater amberjack were caught around Pelagie islands, and transferred by cages near to the coast, and then transported in a land-based farm. Two hormonal protocols were used on 6 mature females hCG at 320-800 U.I. dosage, and long acting GnRHa in EVAc at 20 ?g kg-1 dosage. 3 males were induced with GnRHa at 10 ?g Kg-1. Hormonal treatment induced one spontaneous spawning of 1.116.000 spherical, transparent, and floating (93%) eggs, with a well segmented yolk and a single oil globule. Nevertheless fertilization rate was very low (10.2% of floating eggs). Hatching was observed after 30-34h at 24.1°C. The study confirmed the existence of reproductive dysfunctions in both females and males of amberjack in captivity, and demonstrates the possibility to get good quality eggs by hormonal inductions. In bluefin tuna (BFT), histological study of ovary and testis were performed on 129 individuals (70 males and 59 females) caught in the South Tyrrhenian Sea (Strait of Messina) and in the Sardinia Channel. Some of these fish were transferred in floating cages. Nine stage of oocyte development were described and illustrated, in addition to three types of postovulatory follicle and three stages of ovarian atresia. Histological analysis confirmed that BFT has an asynchronous pattern of oocytes development. All females (n=15) caught in June in the Strait of Messina displayed vitellogenic or mature ovaries with hydrated oocytes with a moderate degree of atresia (13.6%). The rate of atresia increased significantly in females kept in cage for 8 days (68.8%) and two week in cage induced a block of ovarian maturation and the atresia of all vitellogenic oocytes. Reproductive period lasts from Mid May to early July. Mature females were found in June while mature males were found in March, May, June and July. On the base of this study a new spawning area was identified in the Strait of Messina.
Keywords
Tuna;
Amberjacks;
Aquaculture diversification;
Fish reproduction;
Aquaculture development;
Fish;
Broodstocks;
Marine Region
71
South of Sicily (GSA 16)
1
Marine Region Map
