Document Type : Research Paper

Authors

• BAGHER AMINIAN fatideh ¹
• zabiholla bahmani ²
• mohammadreza abbasi ³

¹ * Aquatics and Fisheries Education Department . Gilan Agricultural and Natural Resources Research and Education Center. AREEO. RASHT . IRAN .

² Persian Gulf and Oman sea Ecological Research Center, Iranian Fisheries Science Research Institute, Agricultural Research, Education and Extension Organization, Bandar Abbas, I.R of Iran

³ Educated graduate of fishing technology and fish Branch operation

Abstract

The purpose of this research is to study and investigate some biological indicators of free-range fish in the central part of the southern shores of the Caspian Sea.For this purpose, some biological characteristics including age, gender, sexual ratio, growth parameters were investigated.In this research, which aimed to investigate the latest biological and biometric status of Salmo trutta Caspius in the fishing basket of coastal Beach seine in the central part of the Caspian Sea (Tenkabon to Chalus region of Mazandaran province) in the fishing year of 1400.The mean (± standard deviation) length of the total free fork of the caught fish was 418±55 mm and its weight was 945±259 grams, and the relationship between the length and free weight of the fish with equation 3.21 W=0.862 TL; (R2=0.958) for female fish and 3.24W=0.908 TL; (R2=0.764) negative allometric growth pattern has been obtained for male fish species.Van Bertalanffy growth equation was calculated for all fish Lt=452.6(1-e -0.68(t+3.27).The free-range fish population is in the age range of 3-8 years, and 4-year-old fish have the largest share with 35.42%.The free sex ratio of female: male fish is 3:4, which shows a statistically significant difference between the sexes. (X2=17.59; p<0.001).The rate of gonadal index (GSI) has an inverse relationship with age and its maximum point is seen in March.The results of the present research showed that the annual changes in free-catch of fish in the nets of fishing cooperative companies,

Keywords

• salmon
• beach
• seine
• fishing

Main Subjects

• Ecology