Technical Notes: Spawning Frequency and Egg Production of Captive Spotted Seatrout

Abstract Nine mature spotted seatrout Cynoscion nebulosus (seven females and two males) were placed in a recirculating-water culture system at the University of Miami Experimental Hatchery in July 1993. Photo-period and water temperature were maintained at 14 h light: 10 h dark and 27.5°C. Spotted seatrout held in this controlled photo-thermal culture system spawned on 172 occasions between August 1, 1993, and April 22, 1994, producing approximately 168 million eggs. On average, spawning occurred every 1.5 d. The 172 spawns during the 265-d spawning period represent an average of 24.6 spawns/female or 1 spawn/female every 10.8 d. The mean volume of eggs collected per spawn was 306 mL (SD = 215). The estimated average number of spotted seatrout eggs per milliliter was 3,184 (SD = 499). The mean percentage of viable eggs per spawn was 47.5% (SD = 29). Spotted seatrout held in the constant photo-thermal regime of 14 h light: 10 h dark and 27.5°C consistently produced eggs over a 9-month period.