Assessment of some nongenetic factors that affect egg mass weight of channel catfish, Ictalurus punctatus

Channel catfish, Ictalurus punctatus, is one of the most important fish species for aquaculture worldwide. Egg mass production is directly related to the success and profitability of hatchery farms assuring an adequate egg and consequently fry and fingerling quantity. Most of the success of hatchery farms in Mexico rely on the capacity of production for enough fry to cover the demand of grow-out farms. An analysis was performed with the purpose of estimate the effect of year, month, color, pond and water temperature on egg mass weight data (EMW, g) (n = 3201). The overall mean for EMW was 683.21 g. The effect of all assessed factors was highly significant (P < 0.0001). Pond and year effects suggested an effect possibly related to management strategies. Month indicated an important effect on early spawning, and water temperature showed a highly significant effect of gradient pattern on EMW (P < 0.0001), with a linear slope of -67.8 g by increasing temperature degree. Results confirmed the importance of non-genetic influence on egg mass production, supporting the need for attention of this highly variable trait and suggested the possible improvement on this reproductive indicator through the better control of environmental sources of variation.