Population Characteristics of Carp from Todurge Lake in Sivas, Turkey

Abstract

The study investigates certain fishery biology data including age and sex distributions, growth in length and weight, length-weight relationship and condition coefficient of C. carpio population, which is one of the biologically and economically the most important species in view of population density in the ichthyofauna of Todurge Lake. A total of 211 samples (96 females, 115 males) were caught with monthly periods between May-November 2007. Female: male ratio of population was calculated as 1.00:1.20. Age of the samples was between 1-7 years. Dominant age group was II for female samples and III for male samples in stock. Representation rate of the samples within the population was 39.8% for the first two age groups, while it was 5.7% for the last two age groups. This result indicates that the C. carpio population was composed of young individuals and may be exposed to intensive fishing pressure. Fork length ranged between 83-405 mm and body weight was between 10.2 and 1049.8 g. 28.13% of the female individuals were included in 110-159 mm length group, while 22.61% of males were in 160-209 mm length group. Females with 0-100 g body weight accounted for 61.46% of population, while it was determined as 38.26% for males. Representation rate of individuals in stock, which were taller than the smallest prey size (35 cm, in SL), in other words, fishable stock amount constituted around 15-20% of the stock. Fishing of individuals smaller than 35 cm in Todurge Lake should be banned. Mean fork length changed between 90.7 and 389.0 mm and body weight was between 14.9 and 939.7 g. Mean length and weight values of the individuals in the first four age groups have significantly reduced for the last 20 years. Allometric growth equations was W= 0.0103L(2.8497) for females and W= 0.0085L(2.8534) for males. Both the female and male individuals were determined to follow allometric growth. Condition factor changed between 1.57-2.01 for female individuals and 1.47-2.01 for male individuals. It was determined that the condition level and growth performance of the population in length and weight have significantly reduced for the last 20 years. (C) 2011 Friends Science Publishers