Publication Date:
2021-05-19
Description:
Blackmouth croackers (Atrobucca nibe) resources are the most important commercial stocks in the north-west of
Oman Sea, exploited as lantern fisheries by catch with trawlers vessel. At least 50 specimens were sampled
monthly from September 2012 to July 2014. Results showed blackmouth croacker have several small peak in
gonado-somatic index, but the most frequency of adults occurred in May. The female: male ratio was calculated
1:0.8 and the LM50 was estimated at 35 cm. The mean of absolute and relative fecundity were estimated 92988
and 223 respectively. LM50 and LC50 were calculated and the results showed this species mainly caught before
length of maturity, and the mass populations have not sufficient opportunity to reproduction. The mean of egg
diameter for black mouth croaker were calculated at 533±103. Linear model of Fecundity= 9597.6TL-233880
was calculated for length-fecundity relationship . Results of feeding showed lantern fishes (65%), shrimps
(11%), Japanese threadfin bream (13%) and the other fishes (11%) were the main feeding regime of black mouth
croaker. This species was carnivore, the food prefect mainly consisted of lantern fishes (57.7%) and shrimps
(28.2%). The vacuity index (87.7 %) indicated this spices was low appetite fish.
Total length range was 18 to 47.5 cm with mean length of 28.7 cm, and the class of 23-24 cm was the most
frequent length in fishing ground. The length-weight relationships in A. nibe were calculated for female and
male W= 0.0121L2.9385 and W= 0.0075L3.0737 respectively, both have isometric growth. Growth parameters of
L∞ and K were estimated 50 cm and 0.2 y-1 respectively. Parameters of t0, Tmax and Ǿ were calculated -0.7 year,
14 year and 2.69 respectively. This species have two recruitment period, and the peak of recruitment was
occurred in May with 23.14 percent. Total mortality , natural mortality and fishing mortality rates were
calculated 0.53 y-1, 0.46 y-1 and 0.07 y-1 respectively. Due to the calculated exploitation rate (0.13), it is
appreciated the improvement of black-mouth croaker in the Oman Sea. Base on seasonal and monthly CPUE it
was resulted the peak of fishing density were occurred in the winter. Results showed the main distribution of
black-mouth croaker concentrated on the continental slope in 200 m depth, but these stocks move to deeper
waters ( more than 200m) in warm season and extend to shallow waters (less than 200m) in winter.
Description:
Iranian Fisheries Science Research Institute
Description:
Published
Keywords:
Atrobucca nibe
;
Reproduction
;
Feeding
;
Growth Parameters
;
Mortality rates
;
Exploitation rate
;
Distribution
;
Survey
;
Black mouth Croaker
Repository Name:
AquaDocs
Type:
Report
,
Refereed
Format:
87pp.
