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    Age, growth and reproduction of Acanthalburnus microlepis, filippi 1863 from the Ya?an region of the Aras River, Turkey
    (2001) Türkmen, Mustafa; Erdo?an, Orhan; Haliloglu, H. Ibrahim; Yildirim, Ayhan
    The age, growth and reproduction characteristics of 1105 Acanthalburnus microlepis from the Ya?an region of the Aras River, Turkey. Were determined from monthly samples. Ages ranged from 1 to 7 years. The sex ratio was approximately 1.0 (51.49% males. 48.51% females). Females attained greater size and age than males. Von Bertalanffy growth parameters were: L?=29.87 cm. K= 0.1049. to= -1.92. The length-weight relationships for males and females were found to be W=0.0099L3.098 and W=0.0118L3.052 respectively. The condition coefficients of males and females were calculated as 1.192 and 1.209 respectively. Both sexes matured at the age of 2 years. Spawning started in early May and continued to the end of July. Fecundity ranged from 2830 to 9705 eggs/female and correlated significantly with fish length, weight, age and gonad weight.
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    Öğe
    The growth and reproduction characteristics of chub Leuciscus cephalus orientalis (Nordmann, 1840) living in the River Aras
    (1999) Türkmen, Mustafa; Halilo?lu, H. Ibrahim; Erdo?an, Orhan; Yildirim, Ayhan
    In this study, the populations structure, growth and reproduction characteristics of 1091 Leuciscus cephalus orientalis from the Yagan Region of River Aras between December 1995 and November 1997 were investigated monthly. The age composition of this species ranged between I and VIII. Individuals were composed of 48.85% males and 51.15% females. Female individuals attained greater size and age than males. The largest Female captured was 27.5 cm FL and age VIII, while the largest male was 24.1 cm FL and age VIII. Von Bertalanffy growth equations (in length and weight) and length-weight relationships were found as Lt=32.47(1-e(-0.1217(t+1.63))), Wt=502.10(1-e(-0.1217(t+1.63)))3.113 in males and Lt=36.66(1-e(-0.1114(t+1.39))), Wt=745.31(1-e(-0.1114(t+1.39)))3.135, W=0.0093L3.135 in females. Mean condition coefficients of males and females were calculated as 1.326 and 1.333 respectively. Males matured at ages II-III and females at ages III-IV. Spawning in the both years of study occurred between May and July. Fecundity ranged between 3391-17187 eggs/female and was correlated significantly with fish length, weight, age and gonad weight. The minimum fishing size for this species in the River Aras is suggested to be 20.0 cm in terms of total length and it is recommended that fishing be prohibited between May and July.
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    Öğe
    On the age, growth and reproduction of the barbel, Barbus plebejus escherichi (Steindachner, 1897) in the Oltu Stream of Çoruh River (Artvin-Turkey)
    (2001) Yildirim, Ayhan; Erdo?an, Orhan; Türkmen, Mustafa
    In this study, the age, growth and reproduction properties of 627 barbels. Barbus plebejus escherichi (Steindachner. 1897). From Oltu Stream in the Coruh River Basin were investigated during a period from August 1994 to July 1996. The age of this species ranged between age groups 1 and 10, the second age group being dominant. Individuals were composed of 64.59% males and 35.41% females, von Bertalanffy growth parameters and length-weight relationships were Lt=29.35×(1-e-0.139(t+1.640). W=0.0189.FL2.843 (r=0.96) in males and Lt=32.77×(1-e-0.116(t+1.891)). Wt=392.10× (1-e-0.116(t+1.891))2.911. W=0.0152.FL2.911 (r=0.97) in females. Conditions coefficients of males were and females were calculated to be 1.221 and 1.220 respectively. Sexual maturity was 11.45-13.75 cm fork length (2-3 years old) in males and 13.65-15.95 cm (3-4 years old) in females. Fecundity was calculated to be 1256 (3rd age group)-8445 (7th age group) eggs/female. The spawning period was between May and July when the water temperature was between 14 and 19°C in both years.