Some biological characteristics of Liza aurata in the southern coasts of the Caspian Sea

Document Type : Research Paper

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Abstract

This research was conducted in the southern coasts of the Caspian Sea from Babolsar to Bandar-e-Torkaman. Samples were collected from commercial catches (beach seine with a mesh size of 5 mm). Sampling was carried out monthly (from Sep. 1993 to Sep. 1994) to evaluate the biological characteristics including total and fork length, weight, age, gonad weight and sex. The results indicated that scale and operculum can be used for, however, from operculum better results were obtained. The first annulus is not detectable on scale and it is very difficult to distinguish annuli on the scales of aged mullets. This study also showed that maximum growth takes place at the age of 3 years. The b value of relation between length and weight was estimated to be 3.019. Sex ratio was 1:1.3 and females were dominant. The Gonado Somatic Index (GSI) study indicated that the spawning season is September - November. Most spawning accurse on October. Males become ready for reproduction earlier than female. Th.....