Effect of sodium perborate on reproductional aspects of females of Mesocyclops hyalinus ( Copepoda: Cyclopoida)

Abstract

The effect of different concentrations of Sodium perborate on reproductional aspects of females of M. hyalinus, Order Cyclopoida was studied, including mean number of nauplii/cluth and nauplii/female, mean number of nauplii grown to stage Copepodid /clutch and nauplii grown to stage Copepodid / female and the percentage of nauplii grown to stage Copepodid, mean clutch/female and clutch's time interval, Using the concentrations 0.006mg/l, 0.008 mg/l, 0.01mg/l, 0.02mg/l and 0.04mg/l, used 10 females in each concentration and the control treatment . The results showed decreased in mean number of nauplii/clutch reached to 0.20 nauplii/clutch in 2nd clutch at concen. 0.02 mg/l compared with 37.80 nauplii/clutch in 1st clutch in the control treatment, the number of nauplii/female was 227.8 nauplii/female in the control treatment compared with lowest mean 0.40 nauplii/female at concen. 0.04 mg/l. On the other hand, the mean number of nauplii grown to stage Copepodid/ clutch was decreased to 0 nauplii/clutch at concen. 0.01 mg/l, 0.02 mg/l and 0.04mg/l, while the upper mean was 32.10 nauplii/clutch in 1st clutch in the control treatment. The higher percentage of nauplii grown to stage Copepodid was 18.6% in the control treatment in 1st clutch and decreased to 0.66% in the 2nd clutch at concen. 0.008 mg/l, The higher mean number of nauplii grown to Copepodid/ female was 172.4 nauplii/female in the control treatment and decreased to 0 nauplii/female at concen. 0.01 mg/l, 0.02 mg/l and 0.04mg/l. The lowest mean number of clutches between females was 0.3 clutch/female at 0.04mg/l while in the control treatment was 8.8 clutch/female. The upper mean time interval for clutches was 61 hrs in 1st clutch in the control treatment and the interval increased by increasing the concentrations to reach the higher mean 109 hrs. in 2nd clutch at concen. 0.02mg/l.