The reproductive cycle, size at maturity and fecundity of garfish (Belone belone, L. 1761) in the eastern Adriatic Sea

Abstract

A recent study concerning the reproductive biology of the garfish (Belone belone, L. 1761) has been carried out in the eastern part of the Adriatic Sea along the Croatian coastline. Specimens of the fish (N = 3,393) were collected over a 6-year period (2003-2008). Their length varied between 20. 8 and 75. 4 cm (mean ± SD = 38. 3 ± 7. 94). Female garfish were dominant in larger length groups being most apparent during the resting phase of sexual cycle and in the peak of the spawning period, occurring in April and May. The sexual ratio of all specimens was m/f = 0. 98. Males were prevalent in March-at the beginning of the highest spawning activities. Fifty percentage of the garfish population sexually matured at 28. 5 cm of total length. Males and females reached their sexual maturity at 28. 0 and 31. 5 cm of total length, respectively. Spawning began in January peaking during March to May. According to their maturity stages, gonad weight and the gonadosomatic index, males began to spawn one month earlier (April) than females (May). The mean batch fecundity of garfish was 1,242. 46 ± 843. 64 of matured oocytes per ovary. Matured oocyte diameters ranged from 1. 223 to 4. 283 mm with the mean value of 2. 269 ± 0. 332 mm. © 2010 Springer-Verlag and AWI.