Fishery And Population Dynamics Of Caspian Kutum, Rutilus Frisii Kutum (Cyprinidae), In The Caspian Sea
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Date
2010-10
Authors
Bandpei, Mohammadali Afraei
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The Caspian Sea is the largest enclosed body of water in the world. The
water is slightly brackish. The aim of project was to determine length at maturity
(Lm50%), evaluate of feeding items, investigation some of biological aspects included
in sex ratio, growth and age structure, instantaneous mortality coefficient, maximum
sustainable yield (MSY) and break-even point of Rutilus frisii kutum in southern part
of the Caspian Sea. Specimens of Kutum were collected from the catches obtained
from 131 sample sites along the Iranian coast of the Caspian Sea.
The minimum and maximum fork length and weight was 21cm and 58cm
with mean 38.4±6.4 cm; 104 and 2450 g with mean 775.2±382.5 g, respectively. The
sex ratio of males to females was 0.65: 1 (males: females). The condition factor in
Guilan was more than Mazandaran and Golestan provinces. The length at maturity
(Lm50%) of Kutum obtained was 39.1cm. The minimum and maximum absolute
fecundity varied from 15,713 to 130,737 eggs with mean 69,961.7±3,836.4. The
reproduction phase was extended from February to April, peak in March, with the
highest average values 5.52 for males and the highest value was 17.00 for the
females in April. Due to males’ migration from sea to river occurred sooner than that
of the females.
The diet consisted of different prey items, bivalves representing the most
important prey group (59%), and followed by Cerastoderma lamarki (57%). The
instantaneous natural mortality rate was estimated M= 0.46 y-1. Based on total
instantaneous mortality coefficient (Z) from the seasonalized length-converted catch
curve, F (the instantaneous fishing mortality coefficient) as 0.82 y-1 through the
relationship: F=Z-M, and giving a current exploitation rate E (=F/Z) as 0.64 y-1. The
length-at-first capture and age-at-first capture was obtained Lc =36.8 cm and 3.92
years, respectively.
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Keywords
Fishery And Population Dynamics Of Caspian Kutum, Rutilus Frisii Kutum , in The Caspian Sea