Biomass estimation and effect of meteorological parameters on Penaeus merguiensis stocks in the Hormuzgan province coastal waters

This study designed with objective on shrimp population structure biomass, management aspects and meteorological factors that affect on them. This investigation was carried out monthly by swept area method from Bandar Abbas to Sirik area waters. The optimum time for opening fishing season in Hormuzgan province waters in years 1999,2000, 2001 and 2002 respectively were about 9/10/1999, 4/10/2000, 2/10/2001, 28/9/2002 and total biomass for years 1999 up to 2002 were 731, 1350, 636 and 1708 tonnes, respectively. The Pearson correlation test between catch per unit of effort (CPUE) and meteorological parameters showed the significant correlation for mean temperature and moisture (P < 0.05) and for rainfall and evaporation did not show any significant correlation

Estimation of population dynamics parameters of Scomberomorus commerson using modal progression method in the Hormouzgan province waters

Scombermorus commerson is one of the most important commercial fish species in the Persian Gulf and Sea of Oman. To arrange for a sustainable fishing pattern, growth parameters, mortality and exploitation rates of the fish were estimated. Fish length data were collected from 4515 fishes, science April 2007 to March 2008 in three major artisanal fish-landing sites Bandar Lengeh, Bandar Abbas and Bandar Jask in Hormouzgan province waters. The Von Bertalanffy growth parameters (L∞ K and t _(0)) were estimated at 150.24 (cm), 0.66 year ^(-1) and -0.157 year, respectively. The results showed that S. commerson grows very fast in the first 2 years. The results indicated that S. commerson attains its fork length 80.3 cm at the end of first year. The fork length attained at the end of the second, third and fourth years were 114.1, 131.6 and 140.6 cm, respectively. Growth performance index (f) was calculated at 4.1 which were in agreement with the findings of the other studies in the Indian Ocean. Total, natural, fishing mortality and exploitation rate were estimated at 2.11, 0.67, 1.44 year ^(-1) and 0.64, respectively. Five cohorts were distinguished based on Bhattacharya's method

Reproductive biology of jinga shrimp (Metapenaeus affinis) in coastal waters of Hormozgan Province, southern Iran

The main goal of this study was to understand the reproductive biology of Jinga Shrimp (Metapenaeus affinis) that is found in coastal waters of Hormozgan Province and is relatively unknown to the scientific community. To achieve this goal, we conducted a monthly sampling over the years 2001 to 2003 sweeping a long area from Bandar Abbass to Sirik in the south of Iran.We found that the sex ratio is not 1:1 either seasonally (except in autumn 2001) or annually (p<0.05). The peak of spawning of the shrimp observed in spring and also calculated the carapace length of female shrimps at first maturity (LM50) as 27.16mm

Population structure of banana shrimp, Penaeus merguiensis De Man, 1888 in the Strait of Hormoz, Persian Gulf

Monthly length frequency data of banana shrimp, Penaeus merguiensis were collected from the coastal waters of the north east of the Persian Gulf, from January 2012 to January 2013. Software package FiSAT was used to analyze the length frequency data. Growth parameters, mortalities, exploitation rate and recruitment pattern were estimated from the carapace length in the area. Based on length – weight relationships, the estimated parameter a was 0.0015 for males and females and b was 2.8015 for males and 2.7852 for females. The estimated growth parameters: L∞=39.5 mm, K=1.8 year^−1 and t0=-0.08 year^−1 for males and L∞=50 mm, K=1.5 year^−1 and t0=-0.09 year^−1 for females. Longevity was estimated 1.67 and 2.00 years for males and females, respectively. The estimated mortality coefficients, were Z=5.9 (4.89 – 6.92) year−1 (α=0.05), M=2.9 year^−1 and F=3.0 year^−1 for males and Z=5.7 (4.94–6.37) year^−1 (α=0.05), M=2.5 year^−1 and F=3.2 year^−1 for females. The length at first capture, Lc estimated from the probability of capture routine was 23.3 mm for males and 24.2 mm for females. Sex ratio (M:F=1.1:1) was significantly different to 1:1. The exploitation rates of shrimp were 0.49 and 0.56 for males and females, respectively which could get higher because the survival of spawning stock after the fishing season is related to environmental factors and has less effect on the next year’s biomass. Recruitment was continued throughout the year but with one major peak in July to November

Promoting governability in small-scale capture fisheries in the Persian Gulf: The case of Qeshm Island

Source at http://jifro.ir/index.php?slc_lang=en&sid=1.The present study examines the fisheries governance status of small-scale capture fisheries in the northern Persian Gulf. Qeshm Island, which is selected as case study, plays a prominent role in fisheries in the Persian Gulf and territorial waters of the country. The research methodology included in-depth and semi-structured interviews with heads of fisheries cooperatives and fishers to deepen our understanding of the cultural and technical characteristics of local fisheries communities. Subsequently, data was drawn from 322 questionnaires, using a random sampling technique. The analyses indicate that fisheries co-management is at an interstitial situation, while the fishers are willing to cooperate with the government. A finding is also showed that literacy has a significant effect on fishers’ willingness to cooperate with government. There was also a considerable conflict of interest among the fisheries communities in the study area, which makes the implementation of rules difficult. Small-scale fishing communities are generally in a hard-pressed situation, which affects how fishers operate. Our study aims to contribute to improving the governance and governability of small-scale capture fisheries in the region

Cisgenic inhibition of the potato cold induced phosphorylase L gene expression and decrease in sugar contents

To decrease the accumulation of reducing and non-reducing sugar in potato tubers stored at low temperature, a single gene silencing vector pARTPhL-IR, harboring a part of starch phosphorylase L gene as inverted repeats with pdk intron within was constructed and transformed into potato (Solanum tuberosum L.) cultivars Agria and Marfona. Polymerase chain reaction (PCR) of nptII gene and pdk intron indicated that the RNA interference construct was transformed successfully into the genome. Real time RT-PCR analysis of starch phosphorylase L gene in stored microtubers for 90 days at 4°C showed that the expression level of this gene in transgenics ranged from 1.63 to 7.54% of that in the non-transgenic plants. Analysis of sugar content in these plants showed that the total sugar content in transgenic microtubers was significantly reduced compared to the control, up to 35% in line M4. The accumulation of reducing sugars in transgenic lines at 4°C was reduced from 9.13 (in Agria) to 5.57 mg/g fresh weight (transgenic line A5) and from 9.56 (in Marfona) to 6.52 mg/g fresh weight (transgenic line M4), implying that silencing of starch phosphorylase L gene reduced starch breakdown during cold storage conditions.Key words: Cold sweetening, potato (Solanum tuberosum L.), RNA interference, starch phosphorylase L. gene

Relative growth of the fiddler crab, Uca sindensis(Crustacea: Ocypodidae) in a subtropical mangrove in Pohl Port, Iran

The relative growth of the fiddler crab Uca sindensis in Pohl Port was studied. Ten 0.5 m^2 quadrates were randomly sampled monthly during low tide periods from October 2009 to September 2010. A total of 840 crabs, 449 (53.45%) males and 391 (46.5%) ‌ females, were sampled. The Carapace width of males ranged from 5.5 to 13.5 mm (mean ± SD) (8.92 ± 2.04), and of females from 5.0 to 11.5 mm (mean ± SD) (7.95 ± 1.34). Carapace height (CH) and Carapace length (CL), height of the major cheliped (HMC) of males, abdomen width of females (AW), major cheliped length (LMC), dactiluse (D), feeding cheliped (CHF) and merouse (M) were employed as dependent variables and carapace width (CW) as independent variable. The relationship between CW × CH was positive in males and females. The equation (Log CH=Log-4.881+4.681LogCW) for males (P<0.05) and Log CH=Log-1.882+3.299LogCW for females (P<0.05). The females showed allometric positive growth for CW × AW relation to male (Log AW= Log0.784+1.217Log CW) (P<0.05). Also four male crabs were found with two major cheliped in this study. Remarkable ontogenetic changes were observed in the allometric growth of the male major cheliped and the female abdomen, indicating that these structures are closely connected to the timing of sexual maturity. The allometric growth of U. sindensis in Pohl Port mangrove differed from other Uca populations so far studied, indicating that growth could have been influenced by environment variables such as food availability, population density, distribution of vegetation, sex ratio, soil temperature , organic matter, different of surface and sediment

The effects of broodstock age on consecutive spawning performance of wild-caught ablated Fenneropenaeus

The effects of broodstock age on consecutive spawning performance of wild-caught ablated Fenneropenaeus indicus females in four age groups 6, 8, 12, and 14 months old were studied. Assessment duration was 30 days. Age groups were determined based on carapace length of broodstock caught from Jask fishing ground. Maximum female partnership percentage in consecutive spawning was for 12 months old group. Correlation between egg production and hatch in each spawning with number of spawning in 12 months old broodstock was weaker than other groups but this relation has negative and significant (r = -0.38, P0.05) but others groups had significantly higher hatch rate (P<0.05). In general, 12 month group of wild-caught ablated Fenneropenaeus indicus females showed much higher number of egg produced, hatch percentage, females partnership percentage for 4 spawning in the 30 days period

Fishing pattern, maximum constant yield (MCY) and recruitment pattern of Thunnus tonggol in Hormuzgan province

Thunnus tonggol is one of the most important large pelagic fish species in Hormuzgan province waters. Nominal catch of T. tonggol in 2010 was 32405 tones comprising 65% of total catch of large pelagic fishes. For sustainable exploitation of the resources of this fish, we need to identify its fishing pattern, maximum constant yield and recruitment pattern. Hence, length and weight data were collected randomly from 6 major artisanal fish-landing sites Hassineh, Kong, Bandar Abbas, Salakh, Sirik and Jask in Hormuzgan province, starting in April 2010 over one year. Growth parameters L∞ and K were estimated at 112.23cm 0.3 and (1/year), respectively. Hence, the natural mortality was calculated at 0.43 (1/year) and the maximum constant yield was computed at 11880 tones. Length-weight power relationship, W= aFLb , was W= 3×10-05FL2.82 that showed T. tonggol have isometric growth. Fishing pattern indicated that almost 85% of the catch was under the size at first maturity. Maximum recruitment pattern was in November with average fork length being 27cm. For optimum exploitation of T. tonggol stocks, we suggest two approaches including fishing ban in the maximum recruitment time and gear (Drift gillnet) modification