OUT-OF-SEASON SPAWNING OF SUNFISH LEPOMIS SPP. IN THE LABORATORY

Abstract Although propagation of sunfish Lepomis spp. has historically been done in earthen ponds, there is interest in producing these fish in the laboratory. The objective of this study was to spawn sunfish out of season by means of temperature and photoperiod manipulation. By manipulating temperature and photoperiod, we were able to spawn bluegills L. machrochirus over a 6-month period (December 1994–May 1995): 41 spawns. averaging 20.000 larvae each, were obtained from 24 females. By manipulation of photoperiod alone, we were able to spawn fish during a 3-month period (October–December 1995): 21 bluegill spawns of about 20.000 larvae each and 7 spawns of hybrid sunfish (female green sunfish L. cyanellus × male bluegills) of about 10,000 larvae each were obtained from 12 female bluegills and 24 female green sunfish, respectively. This protocol allows for production of sunfish larvae, regardless of season and without the use of hormones, for both laboratory studies and aquaculture stocking.