Biological and ecological aspects of South Caspian Spirlin (Alburnoides eichwaldii, De Filippi, 1863) from Tajan River, Northern Iran

Authors

1 Department of Fisheries Sciences, Faculty of Environmental and Fisheries Sciences, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran

2 Department of Fisheries Sciences, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Resources University, Sari, Iran

10.22092/ijfs.2024.131751

Abstract

Age, growth, and reproductive traits of the South Caspian Spirlin in the southern part of the Caspian Sea basin, Tajan, River, were investigated. A comprehensive study was conducted on 663 specimens including 226 females, 297 males, and 140 unsexed individuals with a total length ranging from 25.88 to 121.66 mm. The specimens were collected using an electrofisher at monthly intervals. The female-to-male sex ratio was calculated as 1: 1.29. The growth rings on the scale were employed for age determination in this study. Both sexes exhibited only four age groups (0+ to 3+), with the 2+ age group dominating the population. Females consistently displayed larger sizes compared to males. The von Bertalanffy growth function yielded  and  for males and females, respectively. Furthermore, the Fulton condition factor value was significantly higher in females than males. Notably, the maximum gonadosomatic index for both males and females coincided with the spawning seasons (May to August). Absolute fecundity varied from 290 to 1710 oocytes, with a mean of 793 oocytes. This study presents comprehensive data on the biological characteristics of the South Caspian Spirlin, providing valuable insights for fish stock assessment studies.

Keywords