The reproduction biology of Caspian vimba, Vimba vimba (L.), was investigated on the southwestern coast of the Caspian Sea using 712 fish specimens collected at three fisheries catch stations located in Talesh, Anzali, and Kiashahr over a two-year period from April 2012 through June 2013. Seasonal changes in the gonadosomatic index, gonad histological status, size frequency distribution of oocytes, and the fecundity of the species were studied. The peaks of the gonadosomatic index (GSI) were observed both in females and males in June 2012 and May 2013 indicating the variable peak spawning time of this species. Histological examinations and oocyte frequency distribution patterns showed synchronous oocyte development in the Caspian vimba. Absolute fecundity ranged from 5873 to 35421 eggs. The size at first maturity for females was 120 mm FL. We concluded that the Caspian vimba is a total spawner with variable spawning dependent on environmental factors.
Abstract. This study was conducted to complement existing data about the life cycle of Caspian vimba, Vimba vimba (L.), with estimations of age, growth, and mortality rates. To achieve this, 811 specimens were collected between May 2012 and June 2013 at three fisheries catch stations in southwestern regions of the Caspian Sea including Talesh, Bandar Anzali, and Kiashahr. The growth rate in vimba is relatively high at approximately 0.29 year -1 for females and 0.32 year -1 for males.Asymptotic lengths are 245 mm and 233 mm for females and males, respectively. The growth pattern was isometric for both males and females. The overall sex ratio was balanced (1: 0.92). The instantaneous coefficients of total, natural, and fishing mortality were 1.27, 0.4, and 0.8 year, respectively, and the current exploitation ratio was 0.63 year -1. Results showed that the growth rate of males is higher than that of females. Considering the exploitation ratio, it is apparent that the vimba population is experiencing significant legal and illegal exploitation pressure.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.