جستجوی مقالات مرتبط با کلیدواژه "شاخص گنادوسوماتیک" در نشریات گروه "زیست شناسی"

. In this survey length-weight relationships, gonadosomatic index (GSI) and histological characters of gonad were investigated in female fish Capoeta damascina. For doing that, sampling was performed monthly from Sezar River in vicinity of Sepiddasht town, lorestan during nine months from October 2012 to June 2013. After sampling the specimens were transferred to a laboratory where biometric measurements were first executed. Later, the gonads were dissected and after measuring dimensions they were processed for histological examinations. Data obtained from biometric assays demonstrated that a negative allometic growth pattern observed in this species. Moreover, the greatest value of GSI is seen in May. In addition, histological surveys showed that the ovary is saccular and six distinct stages can be distinguished during development of oocytes. Results provided here indicated that during the autumn and the winter the oocytes grow and differentiate whereas the spring, specifically May, is the phase of short-time spawning.

In this study were reviewed some biological characteristics including sex ratio, gonadosomatic index, fecundity and egg diameter Carassius gibelio in the study area from February to September 2015. During the study, 222 specimens from Boostan dam and 238 specimens from Alakoli Reservoir were sampled using small beach seine. The maximum total length and weight of Boostan dam for females and males respectively 206 mm, 141.12 gr and 126 mm, 33.90 gr and in the Alakoli Reservoir for females respectively 196 mm, 114.65 gr and for males was 190 mm, 98/64 gr. The sex ratio of fish caught from Boostan dam to 1:7.88 and the sex ratio of fish caught from the Alakoli Reservoir was 1: 10/90. The highest average gonadosomatic index (GSI) in Boostan dam for female in April (10.27±4.40) and the male (3.56±1.21) in March were observed, This factore in the Alakoli Reservoir area for female (11.73±2.99 ) and male(3.22±0.85) were observed on March and May. The Minimum, maximum and mean absolute fecundity in Boostan dam with 532/08 respectively, 82039/36 and 13119/44 and in the Alakoli pools area 1503/75, 120786/00 and 23174/60 and The minimum, maximum and average were Relative fecundity (eggs per kg body weight) respectively in Boostan dam with 37/54, 4344/34 and 593/10 and in the Alakoli reservoir respectively was 92/97, 23377/20 and 1987/60. The Eggs diameter of 0.11 to 1.00 mm and the average of 0.56 mm in Boostan dam lake area was variable. While this indicator of 0.11 to 1.07 and the average of 0.54 mm in Alakoli Reservoir area was variable.