Biological studies of freshwater fishes, Cyprinion acinaces and Carasobarbus apoensis, from Wadi Khadrah, Saudi Arabia

The present study deals with the analysis of different indices, length weight relationship and age-length relationship of Cyprinion acinaces and Carasobarbus apoensis. The condition factor (K1) for combined sexes ranges from 1.22 to 1.02 for C. acinaces, highest in the spring season and lowest in winter, respectively. The hepato-somatic index for this species was high (3.06) in summer and lowest value (1.67) was recorded in fall season. The K1 values ranges from 1.35 (Winter) to 0.74 (Fall) where as hepatosomatic index was high (2.53) in Fall and lowest value (1.46) was recorded in Winter for C. apoensis. The values of b registered were 2.587 and 2.305 for C. acinaces and C. apoensis, respectively. The relationship for age-length were recorded as L_t = 12.106{1 − e^{−0.80(t+(0.26))}} for C. acinaces and L_t = 23.806{1 − e^{−0.25(t+(0.11))}} for C. apoensis. It was also registered in both the species that the increment in the length was decreased with the increase in age but the yearly increase in weight was high with the increase in age. Length at previous years (back calculated length) were also calculated using year marks (annuli) formed on the scale. It was registered that the increment in length was more in the first and second year of life which decreased in subsequent years.