Naslov
Gonad development of Adriatic cage-reared tuna

Autori
Mladineo, Ivona ; Miletić, Ivana

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
AQUA 2006

Mjesto i datum
Firenca, Italija, 09.05.2006. - 13.05.2006

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Bluefin tuna; Thunnus thynnus; Adriatic

Sažetak
Bluefin tuna (Thunnus thynnus) is subjected to an intensive fishing pressure that has raised questions concerning the proper stock management and its survival, thus the knowledge of tuna reproductive biology is extremely important in order to allow the management of the species, aimed to its conservation, as well as to enhance the possibility of its domestification. Our preliminary study comprised routine histology of fish gonads, sampled at the entrance in cages, during early summer and during the harvested in wintertime. The results showed that first signs of maturation are histologicaly visible in fish over 20 kg. In females, first small oogonia are visible in February, scattered in connective tissue. This was observed surprisingly in a small specimen of only 4.45 kg. In large fish over 50 kg, previtelloogenic oocytes measuring 54.76 &plusmn ; 26.38 were found in January (fig. 1), as well as first spermatogonia in large males of over 50 kg. In August, however, one specimen was found with empty seminifer tubuli, showing only residual clamps of sperm, indicating possible postspawning period (fig. 2). First sex differentiation can be assessed in fish over 20 kg, in rare cases earlier, while spawners usually weight over 30 kg. Spawning period in Adriatic could be during June – August.

Izvorni jezik
Engleski

Znanstvena područja
Veterinarska medicina

POVEZANOST RADA