Gonad development of Adriatic cage-reared tuna (CROSBI ID 521579)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | međunarodna recenzija
Podaci o odgovornosti
Mladineo, Ivona ; Miletić, Ivana
engleski
Gonad development of Adriatic cage-reared tuna
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 ± ; 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.
Bluefin tuna; Thunnus thynnus; Adriatic
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Podaci o prilogu
2006.
objavljeno
Podaci o matičnoj publikaciji
Podaci o skupu
AQUA 2006
poster
09.05.2006-13.05.2006
Firenca, Italija