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Recently the previous Caspian ecosystem is in a catastrophic condition which caused changes in the absolute and relative abundance of the commercially important Caspian kutum (Rutilus frisii kutum) in Iranian waters. The paper presents estimates of yield-per-recruit and spawning biomass-per-recruit under various harvest strategies of F_max, F_0.1, F_30%. It proposes a method for estimating acceptable biological catch (ABC) that accounts for large differences in the quality and quantity of information and available data. The current average Y/R (with F=0.61/y, and t_c=3.2 y) was 218.3 g per recruit, which indicates that the fishery is operating below the maximum Y/R at 236.9 g when t_c = 3.5 y. The Y/R was the highest at F_max and F_0.1, when t_c = 4 y (244.8 g and 214.2 g), respectively. The F_30% value was 0.85/y at t_c of 4 y with the SB/R of 338.3 g. The F_current (0.61/y at current t_c is 3.2 y) is higher than the corresponding reference points, F_0.1 (0.47/y) and F_30% (0.46/y). The ABC of kutum was estimated at 7,850 mt in 2009-2010.

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Aquaculture production is often accompanied by some stressors which undesirable effects on growth and physiological function. Music is one of the cases that could eliminate or reduce the effects of stressors. The purpose of this study was to determine the effect of Iranian traditional music on growth, reproduction and behaviour of zebra cichlid (Pseudotropheus zebra). Fish with an average weight 5.5  0.18 g were put under both music and silence treatment with the number of 2 fish/aquarium with 3 replicates for 4 weeks. Fish under music treatment were put twice a day and every 30 minutes under the Iranian traditional music. At the end of this period, suitable conditions for fish were created to spawning. The results showed no significant differences in growth parameters, but 50 percent of fish during the 2-week were spawned in music treatment. However, only 16.6 percent of fish under silent treatment were spawned. Of eggs and spawn time, significant differences were observed between two groups. When is music being played, the fish were found mainly along approach the speakers, while the distribution of fish treated silence was uniform. The results of present study showed that use of music can affect physiological function of fish, which have more tranquility and less stress on fish.

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The life cycle of bobtail squid (Euprymnahyllebergi:Sepiolidae) was investigated by incubating its eggs and rearing the hatchlings at 28.5±0.5°C and 37-38ppt salinity conditions in the Molluscs Research Station (Bandar Lengeh). After 12±3 days incubation, hatchlings with 2.23±0.05 mm mantle length and 4±1 mg wet weight emerged out. Hatchlings were fed with artemia, mysid shrimp and postlarvae of white-leg shrimp. In 30 days, they grew to 5.94±1.18 mm and 254±16 g, in 60 days to 13.96±1.87 mm, and 2.214±0.213 g, and in 90 days they grew to 18.14±2.23 mm and 4.234±0.548 g. First mating and spawning was observed in days 109 and 110, respectively, when the squids were 20.12±2.64 mm in mantle length and 5.849±1.204 g in body weight. Each female laid 70±10 eggs and died 2-4 days after spawning, followed by males after 7-15 days. Results show that bobtail squid have short life span and can easily be produced and succeeded by the next generation under laboratory conditions. 

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Targets:The objective of this study was to control the reproductive cycle and increasing the efficiency of the production of pikeperch (Sander lucioperca) through determining the effects of different photoperiods on reproductive performance and egg and larval quality.
Methods: Pikeperch broodstock with mean weights 1367 ± 55.3 g were exposed to three different photoperiods with light intensity 630 lux including constant light (24L), constant darkness (24D), and 12 h of light, 12 h of darkness (12L:12D) with three replicates for 40 days.
Results: The results showed that the pikeperch reproductive performance was affected by photoperiod. Broodstock under 24L spawned earlier than those of the other photoperiods. The highest spawning were observed in the morning in 24L (66.7 ± 3.5%) and the lowest spawning belonged to the 24D and 12L:12D that never spawned at night. Although fertilization rate and number of eggs per gram  did not show any significant difference in various photoperiods, the timing of spawning and the egg quality exhibited remarkable difference.
Conclusion: The results of this study pointed out to effective application of photoperiod on changing the spawning time, reproductive and induction of out-of-season spawning of pikeperch broodstock. Additionally, these results unequivocally prove that the reproductive performance of pikeperch can be considerably improved and stimulated by an effective photoperiod.

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  Trichiurus lepturus is one of the most important and commericial species in the Persian Gulf and Oman Sea.In order to come up with the responsible fishing pattern,there was a need to identify  reproduction characteristics. Data were collected randomly from April 2019 to February 2020 from six major artisanal fish-landing sites in Hormuzgan Province (Bandar Parsian, Bandar Kong, Qeshm Island, Bandar Abbas, Bandar Sirik and Bandar Jask). In the detection of sexual stages, the 5-stage key of sexual maturity was used at the macroscopic level. In determining the spawning season, the gonado-somatic index(GSI) was used and its comparison in different months. The lowest GSI of female fish was in September (1.2). The highest GSI of male fish was determined in December with a value of 3.1 and after that in May 2.6. Examination of the GSI and reproductive stages showed two main spawning periods in the middle of spring and late autumn. Different sexual stages were seen in all months of the year, which indicated the batch spawning strategy in T. lepturus. During different months, significant differences in the sex ratio were observed, but during the investigation and in total, no significant difference was observed between the female: male sex ratio in the expected ratio of 1:1.The length at first maturity obtained 78.7 cm total length. It is necessary to ban fishing during the spawning season in order to protect the stocks of this species.