The determination of some biological characteristics of the Bulgarian minnow (Phoxinus strandjae Drensky, 1926) living in Melen basin (Duzce)

The present study was aimed to determine some biological characteristics of Bulgarian minnow, Phoxinus strandjae (Drensky, 1926) in Düzce, Melen basin. 159 individuals of P. strandjae, in total, were examined by sampling in October 2015 from the Small Melen Creek of Düzce Melen Basin. The examined sample includes 55 (34.59 %) female and 104 (65.41%) male specimens. Female to male ratio was found as 1:1.89 of 159 specimen. As a result of examining otolith and scale readings of individuals, the age distribution were determined between 0 to 3 for females and 0 to 4 for males. The lengths of females examined within the study was determined 78.16 maximum, while of the males was determined 90.00 mm; the maximum weight for females and males were 5.54 g and 7.78 g, respectively. The length-weight relationship equations calculated for female and male individuals of P. strandjae were W=0,00786xL3.1689 and W=0,0083xL3.1339, respectively. The longitudinal growing parameters calculated according to vonBertalanffy formulation for female and male individuals, and asymptote value for female individuals (L∞) was calculated as 17.509 cm, Brody's growth coefficient (K) as 0,119121 year -1, hypotheticage of fish before hatching (t0) as -1,61512; while the same values for male were calculated as L∞ =18,356 cm, K=0.110261 year-1, t0=-1.63994 year and for all populations as L∞=17.642 cm, K=0,117996 year-1, t0=-1,5942 year. At the end of the study, it was determined that Bulgarian minnow (P. strandjae) in Melen basin to demonstrate positive allometric growth.