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This study is carried out in the Tyab and Yek-Shabeh creeks in the east, and creeks of the Laft and Khamir in the west of the Hormuzgan province from Sep.2016 to Feb. 2017.Ordination metnods(Canonical discriminate function analysis and principal component analysis) were used to interrelationships between biological and nonbiological factors. The studied creeks were classified based on pollutants(Total Petroleum Hydrocarbons(TPH) and Heavy metals) and ecological conditions in three groups: Tyab and Khamir, and Yek-Shabeh and Laft, that is showed the studied factors have the ability to study on the density and diversity of shrimp. From among the six components identified, TPH in Tyab, Laft and Khamir creeks and nitrate and nitrite in Tyab, Laft and Yekshabeh creeks had the most role in relation to shrimp biomass and abundance. Also, among heavy metals in this study, only Iron and lead elements in Laft creek are showed the maximum relationship with biomass and the number of shrimp and banana shrimp among the studied elements. In addition, TPH are did not relationship to the biomass and number of shrimp only in Yek-Shabeh, while in the other three creeks its role has been well defined. TPH and heavy metals did not play a significant role in the number and biomass of shrimp in the creeks of Tyab and Yek-Shabeh(the east of province) unlike Laft and Khamir creeks(the west of province) and the most effects were ecological parameters and bentose communities. In the east of the region, unlike the western provinces of the province, total petroleum hydrocarbons and heavy metals did not play a significant role in the number and biomass of shrimp, and the most effects were ecological parameters and bentose communities.TPH and Heavy metals, with some of the most ecological factors, has had an impact on the number and biomass of shrimp communities the western part of the province (creeks of Laft and Khamir). Also, results of PCA test in evaluating some of the meteorological factors on commercial shrimp catch showed wind parameter had the most negative effect, and rainfall and temperature had a positive effect on shrimp catching. In this study, was highlighted the role of ecological factors as factors influencing on the fluctuations of commercial shrimp catch of the Hormuzgan province in comparison with TPH and heavy metals.Therefore, in order to sustainable management of shrimp stocks in the Hormuzgan province is recommended the control of the factors influencing the biological condition of shrimp in nursery grounds with control of fishing effort. Iranian Fisheries Science Research Institute Published

Qeshm Hara protected area is the largest and only biosphere reservoir in the Persian Gulf and Oman Sea that covered with mangroves. This study was aimed for population structure and species diversity of fishes in Hara protected area. Fishes were sampled monthly in 5 stations by fixed set-net(Moshta), drift set net (Khoorband), trawl survey and beach seine net method from September 2016 to August 2017. A totally of 16521 fish individuals were collected belong to 115 species, 92 genus and 57 family. The most frequent family of fishes were Leiognathidae (40.4 %), Mugilidae(11.4%), Pristigasteridae(5.9%), Clupeidae(5.8%), Gerreidae(5%), Sillaginidae(3.2%). The most dominant species was Nuchequula gerreoides with 6383 individuals (38.6%), along with Ilisha melastoma, Gerres oyena, Nematalosa nasus, Liza melinoptera, Liza klunzingeri, Osteomugil perusii , Sillago sihama, Upeneus sulphureus, Acanthopagrus arabicus and Pomadasys kaakan formed about 75 percent of the all collected fishes. Population dynamics of dominant fishes (16 species) were estimated using length frequency analysis, the results showed that the dominant were high growth rates and short-lived. Most fish have a life span of less than 10 months, only the Liza klunzigeri, Sillago sihama and Pomadasys kaakan have a mean life span of over one year in the studied area. The natural mortality rates of predominant fishes were generally higher than 1, except for Plotosus lineatus, which was 0.92. The fishes exploitation rates were above 0.5, except for 5 species of Ilisha melastoma, Nematalosa nasus, Nematalosa resticularia, Osteomugil persuii and Pomadasys kaakan, were less than 0.5. Investigating the diversity indices in the Hara protected area indicates the biological richness of this area, so that the lowest Margalf index was 42.5 at station 5 and the highest was 9.96 at station 1. The results of the Shannon index showed that station 2 had the lowest with 1.71 and station 1 with the highest score of 3.05. The Simpson index, except at station 2, equal to 0.54, was higher than 0.8 in other stations. The lowest Pilou index was 0.4 at station is 2 and the highest at station 3 with 0.73. The assemblage of fishes follows the clumped pattern distribution. The ABC curve and the W-Statistic index measured in the survey area indicate a desirable situation and the none-stress conditions in the Hara protected area. Iranian Fisheries Science Research Institute Published

The feeding habits and trophic level of Himantura gerrardi were studied according to sex and size classes of 80 individuals obtained using bottom trawl between May and December 2014 from the Oman Sea. Collected specimens were divided into three size classes (small58 cm) based on disk width. Prey was identified in seven main zoological categories, where crustacean and polychaetes were the dominant in diets, indicating this species is a demersal dwelling species. No significant differences were observed between sexes, but size classes showed significant differences in their diets. Also, results showed a decrease in feeding overlap between size classes with an increase in disk width, suggesting that intraspecific competition reduced, which allows the coexistence of different size classes. Trophic level was positively correlated with the disk width, which was lower than 4.0 for both sexes and different size classes, placing it in an intermediate trophic level.

Shrimp is one of the most important aquatic animals,that have decreased their stocks in Hormozgan province, especially the eastern province . Evalution of food interaction in shrimp habitats (Estuaries of Tyab, Yek shabeh, Laft and Khouran) was studied with Ecopaht with Ecosim software (ver. 6.5) in Hormuzgan province. After entering the input components (Biomass,P/B and Q/B), model was balanced and outputs were extracted. Results of trophic levels, was close to previous research in these areas for all species in estuaries. Maximum of ecotrophic efficiency was belonged to phytoplankton and other preys that were observed in predator stomachs. Biological future of food web estimated to be threatened based on omnivore index of planktonivore groups. Maximum food competition between the four food models was estimated in detritivores communities in Laft estuary, that may be related to the low density of mangrove in this region. Khamir estuary ecosystem could be more stable, because each impacting group had its own separate ecological niche and special predation territory. key indices in each of four food models were related to phytoplankton communities, this key role has been demonstrated much better in Yek Shovy estuary than others. Future of commercial shrimp stocks will be expected to be in better condition in Khoran estuary compared to other three ones, due to selection of separate ecological niche by predators and High biomass of detritus in this estuary.

This study is carried out in the Tyab and Yek-Shabeh creeks in the east, and creeks of the Laft and Khamir in the west of the Hormuzgan province from Sep.2016 to Feb. 2017.Ordination metnods(Canonical discriminate function analysis and principal component analysis) were used to interrelationships between biological and non-biological factors. The studied creeks were classified based on pollutants(Total Petroleum Hydrocarbons(TPH) and Heavy metals) and ecological conditions in three groups: Tyab and Khamir, and Yek-Shabeh and Laft, that is showed the studied factors have the ability to study on the density and diversity of shrimp. From among the six components identified, TPH in Tyab, Laft and Khamir creeks and nitrate and nitrite in Tyab, Laft and Yekshabeh creeks had the most role in relation to shrimp biomass and abundance. Also, among heavy metals in this study, only Iron and lead elements in Laft creek are showed the maximum relationship with biomass and the number of shrimp and banana shrimp among the studied elements. In addition, TPH are did not relationship to the biomass and number of shrimp only in Yek-Shabeh, while in the other three creeks its role has been well defined. TPH and heavy metals did not play a significant role in the number and biomass of shrimp in the creeks of Tyab and Yek-Shabeh(the east of province) unlike Laft and Khamir creeks(the west of province) and the most effects were ecological parameters and bentose communities. In the east of the region, unlike the western provinces of the province, total petroleum hydrocarbons and heavy metals did not play a significant role in the number and biomass of shrimp, and the most effects were ecological parameters and bentose communities.TPH and Heavy metals, with some of the most ecological factors, has had an impact on the number and biomass of shrimp communities the western part of the province (creeks of Laft and Khamir). Also, results of PCA test in evaluating some of the meteorological factors on commercial shrimp catch showed wind parameter had the most negative effect, and rainfall and temperature had a positive effect on shrimp catching. In this study, was highlighted the role of ecological factors as factors influencing on the fluctuations of commercial shrimp catch of the Hormuzgan province in comparison with TPH and heavy metals.Therefore, in order to sustainable management of shrimp stocks in the Hormuzgan province is recommended the control of the factors influencing the biological condition of shrimp in nursery grounds with control of fishing effort. Published

This trawl survey was carried out during 2013 for the stock assessment of families Haemulids, Nemipterids and Ariids in the Oman Sea. Sampling was carried out at five different stratum and depths. The highest value of CPUA of Haemulidae was estimated for Pomadasys stridens in “B” stratum (885.78 kg nm^-2), for Pomadasys kaakan at depths of 10-20 m (330.35 kg nm^-2), and for Nemipteridae it was estimated for Nemipterus japonicus in “D” stratum (1042.31 kg nm^-2) at 30-50 m depths (1734.97 kg nm^-2), and for Ariidae, it was estimated for Netuma thalassina in the stratum B (752.64 kg nm^-2) at 20-30 m depths (428.33 kg nm^-2). The highest biomass for Haemulidae was estimated in stratum B (320.53 ton) at 50-100 m depths (282.98 tons), and for Nemipteridae in “D” stratum (559.72 tons) and at depths of 30-50 m (604.04 tons), and for Ariidae it was estimated in “B” stratum (272.35 tons) and at 50-100 m depths (255.12 ton). Based on the results obtained, the highest species diversity for Haemulids was in “A” stratum at depths less than 50 m, while for Nemipterids it was similar in the total study area and different depth layers. Highest species diversity for Ariids were found in “A” and “D” strata at depth layers of 10-20 m and 30-50 m, respectively. In light of the fact that fishing efforts decreased during these years, our results illustrate that CPUA and biomass have ascending trends which indicate the relative stability of the stocks of these families.

Loliginid squids occur in temperate and tropical coastal waters where they have been considered economically important (Valinassab et al., 2006; Anderson, 2000). Uroteuthis (Photololigo) duvaucelii (Orbigny, 1835) or Indian squid is the most abundant group of Teuthida (Family Loliginidae) in the Persian Gulf and Oman Sea (Valinassab, 1993). These squids demonstrate complex population structures, and are generally characterized by different biological features such as growth rates, size and age of maturity. Over the past 30 years age determination through interpretation of growth increments in the microstructure of the hard structures of squids has accounted for many of the issues and limitations. Naef (1921) was the first to identify growth increments on gladius. The gladius is the internal chitinous shell present in squids, which supports mantle muscles, fins and inner organs. Increments were observed in the middle plate on the dorsal surface of the gladius (Arkhipkin et al., 2012). The series of increments of gladius indicate the amount of daily growth in these species (Perez et al., 2006).

Nemipterid fishes are considered as one of the commercial fish family having considerable catch amount in the Persian Gulf and Oman Sea. There was an annual monitoring survey during 2003-2013 in the Oman Sea using a research bottom trawler for stock assessment purposes. The whole area was stratified into five strata (or sub region) and four depth layers of 10-20, 20-30, 30-50, 50-100 m. The results showed that the best fishing ground for this family were both in western and eastern study area of the Oman Sea, Sistan-o-Baluchistan Province. Amongst five classified sub regions, the Meidani, Galak, Rabech and Biahi in the western part showing the most density with CPUA value of 293.7 kg/km2. A comparison between different covered depth layers, it was found that the highest CPUA (331.2 kg/km2) belonged to the depths more than 30 m and with decreasing depth there was a descending trend in catch per unit area value with the lowest value for 10-20 m depths (28.6 kg/km2). This 10 years data show the important finding of increasing of density and catch per unit of area of Nemipterid fishes.

This study was conducted to determine the opening and closure of Penaeus semisulcatus fishing season in July, August and September during 2012 - 2014 in the waters of the Bushehr province . 30 stations were hauled based on a Stratified Random Sampling design in three depth layer of less than 10, 10-20 and more than 20 meters. The optimum dates of opening shrimp fishing season for the years of 2012-2014, were calculated as 4th, 28th and 13th July respectively. The closures of Shrimp fishing season for years of 2012-2014 were determined to be 10th September, 29th of August and 5th of September. The estimated biomass were for all of shrimp species in the years 2012-2014, 930, 1009 and 526 tonnes respectively. Penaeus semisulcatus contributed 92, 96 and 99% of the shrimp stock in the mentioned years.The CPUE (catch per hour) were calculated to be 1.6, 16.9 and 6.9 kg per hour, in the years 2012-2014, respectively. The highest aggregation of Green tiger Shrimp (P. semisulcatus) were observed in 10-20 depth meters layer in southern waters of Bushehr province at the fishing areas (Motaf to rostami). The changes in climatic conditions resulted in differen dates of the opening season and probable illegal fishing may have caused the reduction of shrimp biomass in recent years. Hence to Protect the stocks the economic species and the sustainability of shrimp fishing, it is neccesary to properly manage fisheries and determine the opening and closure fishing season Penaeus semisulcatus through conducting research surveys. Iranian Fisheries Science Research Institute Published

Dasyatidae is primarily a marine subfamily, which is most common in shallow tropical waters. The species of this family are distributed worldwide; from tropical to warm temperate; Atlantic (Including the Mediterranean Sea), the Indian, and Pacific Ocean. Six genera, Dasyatis (synonyms Trygon and Urolophoides), Himantura, Pastinachus (synonym Hypolophus), Pteroplatytrygon, Taeniura, and Urogymnus, with about 68 species are included in this family. In the Persian Gulf, some members of family Dasyatidae are important species in terms of number and biomass. This family is represented by three genera (Dasyatis, Himantura and Pastinachus) and seven species, although they have been frequently confused by forms and colors. ... In this study, first report of H. granulata from the northern Persian Gulf with some morphometric measurements is given.

Monthly samples of Acanthopagrus latus (Houttuyn, 1782) were used to determine (1) feeding habits and (2) reproduction characteristics of the species in relation to its size, spawning season and sex in the northern part of the Persian Gulf from January to December 2013. The smaller length classes of all samples were dominated by male fish. All gonads examined, were ovotestis during the spawning period from February till May. Male and female ovotestes were dimorphic in structure which represented a transitional stage in a protandrous sex change. Length at first sexual maturity of female A. latus was 24.40 cm. A. latus fed predominantly on bivalves, gastropods, cephalopods, stomatopods, fish and decapods which showed changes according to the season and body size. According to our results, it appears that A. latus feeds throughout the year; the highest value of gastrosomatic index (GaSI) for both sexes was recorded in February, which was significantly different from that in other months. The results of this study also indicate that feeding in yellowfin seabream is very intense before reproduction (during January and February). It decreases gradually after February to June during the spawning season.

This study was carried out to determine the seaweed biomass in the coast of Sistan & Baluchestan Province. Beris, Chabahar, Pozm and Tang were introduced as high density zones and Jood & Lipar were selected as low density zones. Among 354.2 km of investigated coastal area, 18.2 km were high density zone and 281.5 km were low density zone. Three transects were fixed in study areas and sampling randomly was done monthly. The samples were measured in area after being cleaned, and separating. During this research, 9 genus were collected. Among these seaweeds, 2 genus were green algae (composed of 2 families and 2 orders), 6 genera of brown algae (composed of 3 families and 3 orders) and 1 genus of red algae. Wet biomass of Sargassum genus in the total area of Sistan & Baluchestan coasts was 445.9 tons in 2012. Among this biomass, 269.1 tons (60.35%) was found in high density area and 176.8 tons (39.65%) in low density zone. The maximum biomass, 270.4 tons (high density zone: 155.5 and low density zone: 114.9 tons) was obtained in December, and the lowest biomass, 3.5 tons was obtained in March.

An ecosystem-based management fishery is a new way of looking at management of living resources. Trophic levels of basic food items, feeding habits, growth and mortality rate of 20 exploited fish species (including commercial and bycatch) are investigated in the Persian Gulf (from the provinces of Khuzestan, Bushehr and Hormozgan,) from 2010 to 2012. The model considers trophic interactions among 12 functional group of the ecosystem involving Phytoplankton, Zeoplankton, Cephalopods, Shrimp, Infauna Benthos, Epifaunal Macrobenthos, Demersal Zoobenthos Feeders, Small Pelagic Planktivorous Fish, Benthoplagic Feeder, Piscivorous, Large Benthic Carnivores And Small Benthic Carnivores. In general 7452 of stomach contents samples were analyzed based on the weight and numerical method and were detected about 40 preys. The results demonstrated gaps in our knowledge on the food web structure. The mean trophic levels were varied from L. klunzingeri (2) to S. tumbil (4.64), while the total catch of some species were fluctuating widely. Result of our study showed that Total mortality varied between 0.45 per year (A. suppositus) to 9.5 per year (P. indicus) and food consumption rate also fluctuated by 1.9 (L. johni ) to 89 (L. lineolatus). The results indicated that some fish species including sardine, Anchovies, small carangids, S. stridens with high frequency in ecosystem, have been occupied in the food web as a wasp-waist. The model showed that most hunters groups live in middle levels in the food web such as N. japonicas, A. latus, P. kaakan, L. nebolusus, P. indicus and T. lepturus . Analysis the catch rate during 2001-2011 reveled that there is a clear trend of declining most of fish species catches in this research except for T. lepturus, P. kaakan and sparids which lead to upset the fundamental ecological balance of the Persian Gulf in future. Iranian Fisheries Science Research Institute Published

In this paper age determination and morphological characteristics of blacktip catfish, Plicofollis dussumieri, from Oman Sea were evaluated. A total of 132 fish specimens were collected from fishing trawlers or landings from March 2011 to July 2012, with minimum and maximum of 245 mm, 195 g; and 767 mm, 5801 g, respectively. Maximum life span was 12 years for the length range of 245 – 767 mm FL, while total body weight (BW) ranged between 195 and 5801 g and the resultant equation was: W = 0.040 L^2.8275 (R^2 = 0.99). High correlation coefficient value found between age and FL was R= 0.97 and for age-BW was 0.94. This value for otolith weight and BW was estimated to be 0.91 and showing that there were significant correlations between measured parameters. Lapillus otolith in blacktip catfish is the biggest otolith among most teleostei fishes, also the Sagitta is the biggest. Lapillus of this species is round, robust, onion-like and without sulcus curve, with no obvious growth increments in rostrum and antirostrum zones. In ventral side Gibbus maculae is concave having prominentia marginalis in anterior and basal line in posterior parts.

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. Iranian Fisheries Science Research Institute Published

The speciemns of red algae “Gracilaria corticata” were collected from the rocky intertidal shores in Bostaneh Port in the Persian Gulf and Lipar in Oman Sea in May, June and August 2013. Anatomical, morphological structures, thallus of vegetative and reproductive samples were studied. Carpogonial and tetrasporangium stages were determined based on histological and morphological methods. The female thallus, the Cystocarp with hemispherical structure through out thallus were observed. The Spermatangial conceptacle was located deeper as the oval shape in male thallus. The tetrasporophytic stage of diploid samples was determined by the presence of tetrasporangium oval shape.

Due to study the food regime of Arius dussumieri, a total of 132 specimens were collected from Oman sea waters, Sistine & Baluchistan province. The stomach content, were taken into consideration and it was found that the amount of full, semi-full and empty stomachs were 31, 33 and 36 percent, respectively; of which the highest frequency was in winter (74%) and the lowest was in summer (24%). On the other hand, the fullness index was studied with the highest and lowest value for spring (44%) and winter (5%), respectively. The GaSI shows that A. dussumieri, has better feeding in spring and summer but feeding (up in male) was decreased in autumn and winter. The Food Preference (FP) Index was estimated as: Fishes (39%), Crustacean (40%) and Molluscs (20%) namely all of them are considered as minor food in all four seasons. The most important food items were identification as fishes: Carangidae, Engraulidae & Leiognathidae; crabs: Portunidae & Porcellanidae; shrimp: Alpheidae; cephalopods: Loliginidae & Opisthoteuthidae; gastropods: Muricidae & Naticidae.

Fishing companies play significant role in value-added generation in Bushehr province. According to the current conditions and based on natural potentials, fisheries are the main sector in economic development of the Bushehr province. The purpose of this paper is to identify, analyze and rank factors affecting productivity of Bushehr fishing companies using group analytical hierarchy process (GAHP) technique. We applied two standard questionnaires which were filled with 100 fishermen and 18 fishery experts. The first group of questionnaires was used to assess the two main factors: Internal and external and five subfactors including: Governmental, structural, natural, soft and hard ware aspects. The second group was used to rank the same indentified factors in the first group of questionnaires. Results indicated that fishery headquarter of the governmental sub-factor, economic changes of the structural sub-factor, management approaches of the software sub-factor and the catch tonnage and its composition of the hardware sub-factor are the main parameters affecting productivity. Suggestions were made to improve productivity of the fishing companies in Bushehr province.

In order to study the feeding biology of the Japanese Threadfin Bream in the Northern parts of Oman Sea (Chabahar Area), a total of 212 specimens were collected in 2009-2010, and different indices of VI, FP and GSI were taken into consideration. Of total stomachs, 51, 44 and 117 numbers were full, semi-full and empty, respectively. The VI index was estimated 55.2%, and amount of Food Preference Index were estimated as: Crustacean (63.2%), Fishes (38.9%), Molluscs (36.8%), Nematoda (25.3%), Polychaeta (8.4%), Sipuncula (7.4%), Foraminifera (6.3%), Phytoplanktons (4.2%), Seeweeds (2.1%) and Nemertean worms (1.1%). The maximum and minimum Gastro-Somatic Index for males was in autumn and winter season; and for females in summer and spring. It was concluded that N.japonicus is a moderate feeding fish and its main food is Crustacean and minor foods are Molluscs and Fishes.

The coral reefs are one of the most important and rich ecosystems in the world and are considered as major habitat for different species group of fishes. Fourteen islands are found in the northern Persian Gulf including Larak Island of which the coral regions around this island were determined and then for sampling, 6 stations were randomly selected by Manta Tow method in July to December 2010. The identification was conducted using Visual Census technique in 6 stations. A total of 54 species belong to 41 genera and 23 families were identified and amongst them the abundant species group belonged to Pomacentridae family with 11 species. The results indicated that however the stations were far from urban area; the species diversity has been higher.

Neste artigo, objetiva-se compreender a percepção e expressão de modelagem matemática de sessenta e três professores de matemática da educação básica. Apresentam-se resultados da pesquisa aplicada, cujos dados empíricos foram obtidos em Curso de formação continuada de modelagem matemática de dezesseis horas, divididas em dois encontros. Os dados advindos da observação e dos registros de questionamentos e discussões, ocorridas no início do segundo encontro, foram analisados por meio da análise do discurso, com aporte na neurociência - memória. Compreendeu-se que esses professores expressam, ao evocarem a memória na forma de redes, as etapas da modelagem matemática diferentemente da ordem trabalhada. A expressão de modelagem por meio de redes, construídas a partir da memória alvo, o tema, evidenciou, inicialmente, o modelo obtido e, na sequência, a etapa desse modelo. A partir dele, expressaram uma rede semântica que conduz constantemente a outras etapas da modelagem matemática.

Mercury, zinc and selenium concentrations were analyzed in the muscle and liver of 25 Whitecheek Shark (Carcharhinus dussumieri) from the coast of Bandar Abbas. The level of Hg accumulation and its interaction with Zn and Se in Whitecheek Shark were studied. Hg, Zn and Se concentrations were determined by an Advanced Mercury Analyzer (LECO, AMA 254), Atomic Absorption Spectrometer (ASS,PU 9400) and Graphite Furnace Atomic Absorption Spectrophotometry (Perkin Elmer 3030) respectively. The mean (±SD) of Hg, Zn and Se concentrations were 0.05±0.02, 0.92±0.25 and 0.13±0.05µg/g wet wt in the muscle and 1.07±0.86, 1.57±0.43 and 0.46±0.19µg/g wet wt in the liver tissues, respectively. The mean of Hg, Zn and Se in liver tissue was significantly higher than muscle tissue. Also, 64% of liver samples showed levels above the acceptable limit established by WHO and FAO. A positive correlation was found between Hg and Se concentrations in the muscle and liver tissues with weight and length variables were statistically significant. In this study, the accumulation of Se in the muscle and liver of Whitecheek shark showed a positive correlation with Hg concentration. The mean molar ratio of Se to Hg found in the muscle and liver were 6.36±1.77 and 2.74±3.61, respectively. Positive correlations between Hg and Se showed efficient detoxifying mechanism and as a result, the possibility of reduction in toxicity of mercury in both tissues via Se-Hg complexes or the binding of Hg with selenoproteins.

Morphometric comparison of sagitta otolith in 10 clupeid species of the Persian Gulf and Oman Sea including Anodontostoma chacunda, Dussumieria acuta, Dussumieria elopsoides, Ilisha megaloptera, Ilisha melastoma, Nematolosa nasus, Sardinella gibbosa, Sardinella longiceps, Sardinella sindensis and Tenualosa ilisha), was conducted during 2007-2008. We found no significant differences in morphology and morphometry of the left and right otoliths except for A. chacunda and N. nasus. For the latter species the left sagitta otoliths were used. Investigation of otolith morphometric characteristics (length, breadth, weight, perimeter, area, and number of scallops) was also conducted which showed perimeter and number of scallops were the most effective individual otolith characteristics for distinguishing between species. The study indicated that sagitta otoliths have particular morphometric characteristics which are useful in identification of these species.

Lanternfish (Benthosema pterptum) is one of the most important fish species in the Oman Sea. We randomly sampled 300 myctophids from different depths in spring and winter 2009 in the Oman Sea using mid-water trawls. Male to female sex ratio was 0.36:0.64. The thin sections (60-80µm) of sagitta otoliths of the fish were prepared using polishing method. These sections showed that increment growth rings of lanternfish otolith are formed daily and the age condition is distinguishable on a daily basis. We found the life span of the species to be short (with a maximum of 349 micro-increments counted) and probably less than a year. The relationship between standard length (SL) and daily growth increment (D) was expressed as the linear equation: SL=0.87D+12.37 (R 2=0.97). The relationship between lanternfish weight (W) and daily growth increment (D) was expressed as power equation: W=0.00003D1.754 (R2=0.95). Furthermore, morphometrical characteristics of otolith including otolith weight and length and daily growth increment relationships were expressed as linear equation (R2=0.96 and R 2=0.83). The results showed that lanternfish growth rate were in the range 0.241mm/d-1 to 0.138mm/d-1 and decreased by body size and age in this range.

We assessed concentration of heavy metals (Cu, Fe, Hg and Zn) in the muscular tissue of benthic species Himantura gerrardi and pelagic species Selar crumenophthalmus caught from the Persian Gulf during winter 2008. After biometrical measurements, the muscle tissues of 51 randomly selected samples were separated from 86 stations. Specimens were digested using the wet method and the concentrations of Cu, Fe and Zn were determined using Atomic Absorption Spectrophotometer (flame method) and also concentration of mercury was determined using Mercury Analyzer device. The mean concentration of heavy metals in muscle tissues of Himantura gerrardi were as follows: Fe: 74.78; Hg: 0.77; Zn: 875.99 and Cu: 3.5. However, these values for muscle tissues of Selar crumenophthalmus were: Fe: 25.07; Hg: 0.20; Cu: Zn: 15.54 and Zn: 2.31kg/g dry weight. Results showed that concentration of the selected heavy metals in H. gerrardi, were significantly higher than Selar crumenophthalmus (P

Over-fishing of marine resources has endangered many commercial fish species in the world; with aquaculture development, setting up artificial reef systems is an important way for marine stocks and fishing enhancement. The present study was designed to monitor fish abundance and species changes around a small and newly established artificial reef system in Moloo area at Bandar-e-Lengeh during two years after installation (Sep. 2005 to Sep. 2007). The artificial reef includes three types of concrete structures arranged in a seven by three grid. Each cross point considered as a sampling station and two other stations selected from two sides of the system as control stations. Based on obtained results CPUE (P = 0.00001), frequency (P = 0.001) and species diversity of captured fishes (P = 0.024) showed significant differences between three types of sampling traps. With type of structures, The CPUE and frequency of fishes in transect 7(mixed structures) showed the significant differences with other six transects (p= 0.001, P = 0.009). No diversity relationships were seen between transects (p= 0.100). In this study there were no significant differences between depths. Although the means of CPUE between seasons were different, but the ANOVA test could not show the significant differences because of the differention between variances. The T-Test showed no significant differences between the numbers per trap per day dominant species (Epinephelus coioides, Plectorhinchus shotaf, Diagrama pictum, Siganus javus) in different seasons. Movie prepared from artificial reefs showed diversity of fish were more than that of fishing by trap. Although fishes increased but there was no enough causes evidences for product in artificial reefs. Therefore, the study need to continue in this area.

Investigation on small pelagic fishes in the north of the Persian Gulf (Qeshm Island and Bandar Lengeh) coastal waters during October 2006 to September 2008, illustrated that 6 sardine and 2 anchovy species were locally existed. Sind sardinella (Sardinella sindensis) and Buccaneer anchovy (Encrasicholina punctifer) were dominated in this area. The peak of sexual maturity for Sind sardinella and Buccaneer anchovy occurred in spring and summer respectively. Reproduction period for Sind sardinella was from the middle of winter to late spring, and Buccaneer anchovy encompassed reproduction capacity all the year. The female: male ratio was calculated 1:0.7 and 1:0.9 for Sind sardinella, 1:1.27 and 1:1 for Buccaneer anchovy in Qeshm Island and Bandar lengeh sequentially. The mean of absolute fecundity were estimated 16234 and 16168 for Sind sardinella, 1277 and 1141 for Buccaneer anchovy in Qeshm Island and Bandar Lengeh respectively. LM50 and LC50 were calculated and the results showed both species mainly caught before length of maturity, and the mass populations have not sufficient opportunity to reproduction. Both species were planktonivore, theirs food prefect mainly consisted of copepods, naplius and bivalves. Vacuity index indicated both spices were semi-voracious appetite fishes. Based on calculated length-weight relationships in S. sindensis and E. punctifer, they have isometric growth. Growth parameters were estimated, the results illustrated that they were growth fast and short live species, which suggested S. sardinella and E. punctifer have 3 and 2 years maximum life span respectively. The recruitment pattern indicated double recruitment peaks per year in both species. Annually, four cohorts were distinguished in Sind sardinella and 3 cohorts in Buccaneer anchovy. Total mortality (Z), natural mortality (M) and fishing mortality (F) were estimated in both species, and the values of exploitation ratio (0.78 & 0.74) in Sind sardinella and (0.72 & 0.41) in Buccaneer anchovy were reasonable for current fishing effort due their short life span. Analysis of the results showed that CPUE in sardine and anchovy affected by reproduction and feeding processes. Results showed significant correlation between sardine CPUE and Sardine GaSI (P

Over-fishing of marine resources has endangered many commercial fish species in the world. Setting up artificial reefs is now considered an important way for marine stocks and fishing enhancement. The present study was designed to monitor fish abundance and species changes around a small and newly established artificial reef system in Moloo area at Bandar- e-Lengeh during two years after installation in September 2005. The anificial reef includes three types of concrete structures arranged in a seven by three grid. Each cross point was considered as a sampling station and two other stations were also selected from two sides of the system as control points. The CPUE and frequency of fishes in transect 7 with a mixed structure showed significant differences with Other 6 transects (P0.01). Although there were differences CPUE averages of different seasons, the ANOVA test of difference significance was negative. The t-test showed no significant differences between the abundance and of different species per trap per day and seasons. The dominant species were Epinephelus coioides, Plectorhinchus shoran Diagrama pictum, Siganus javus.

We collected 478 specimens of Cobia, Rachycentron canadum, from Hormozgan province waters during October 2005 till September 2006, and studied reproductive parameters such as spawning season, sex ratio, maturity stages, fecundity and ova diameter. The maturity and spawning season were investigated through macroscopic and microscopic (ovarians histology) observation. Studying average gonadosomatic index (GSI), the percent of maturity stages and ova diameter average changes revealed that the spawning occurred from July to the beginning of September.

Biology aspects of cobia (Rachycentron canadum) were investigated from October 2005 to December 2006 in Northern waters of Persian Gulf (Hormozgan province).The reproduction cycle, sexual maturity, sex ratio, Fecundity, Lm50, feeding, length frequency, growth parameters and mortality of cobia were studied from total of 509 specimens ranged from 19 to 159 fork length. Gonadosomatic index peaked during spring and summer with main peak in June. Spontaneous spawning occurs around the year with peak in June. The overall female to male ratio was significantly 1 : 1.49 (P

The project “Stock Assessment of Zobaidy, Pampus argenteus, in the North of Persian Gulf” started in April 2003 and completed by the end of April 2006 as a cooperative research project to assess the valuable stock of zobaidy shared between Kuwait and Iran in the North of Persian Gulf. The main objectives were to investigate and determine the basic biological parameters, the standing biomass, seasonal abundance, and the impact of regional fishery activities. These studies are necessary to recommend practical management policies and measures for long-term sustainability of the zobaidy stock. The sampling of fisheries data (catch, effort, fish length distributions, and biological data) was started in May 2003 and ended December 2006. Monthly length frequencies data were collected from both the drift gill net and shrimp trawl fisheries. Age determination was based on otolith sectioning, polishing, etching, and staining method. The age groups ranged from 0 to 10 yrs but the dominant age groups were 1-3 years and the estimated parameters for both sexes were L∞ = 32.0-36.0 cm FL and K = 0.26-0.30 yr-1, females grow faster than males. Sea survey on board of two dhow boats was carried out using swept area method. Higher abundance was always obtained in Kuwait Bay rather than the other areas surveyed in Kuwait and Khuzestan waters. The total estimated stock biomass in the surveyed areas varied from 42 t in January 2004 to 2,633 t in November 2004, while the Iranian biomass varied from as low as 19 t in October 2005 to 295 t in November 2003. The data indicated that Ras Al-Gaid, Bubiyan Island is the main nursery area in Kuwait waters, while Lifah, Busaif, and Bahrakan are important nursery areas in the Khuzestan waters. Kuwait Bay and Khor Musa are considered important spawning grounds and should be protected. Yield per recruit analysis showed that higher yield could be gained with increasing fish effort, which is not recommended under the present status of high exploitation rate. In contrast, virtual population analysis indicated that future catches will reduce if the fishery continues with present level fishing effort. A reduction of 50% would be required to maintain the present level of catches as well as to enhance the stock biomass. Formulation of a joint advisory management committee would be advisable approach to manage and monitor the zobaidy stock in the region. This will need commitment from the three countries in the region for data collection on regular basis on length frequency, statistics, and biological data. Copepods with high occurence of 64% - 88% is considered as the main item in the Pomfret fish, while jelly fish and other decapods crustaceans are considered as minor items. Observation of pre- flexion stage larvae of pampus genus among the specimens collected from Khuzestan coast water could be considered as an evidence for the spawning of this fish in this region. The occurrence of pampus larvae in Khuzestan coast during the months of June to October has been reported for several times. Examination of 101 specimens (38 from Kuwait, 63 from Iran) for molecular survey does not show any significant differences between Kuwait and Iran water stocks for this fish, so it is possible to hypothesize a unit population for zobidy stock in Persian Gulf and Oman Sea as whole. Iranian Fisheries Science Research Institute Published

Coregonus lavaretus is one the important species of coregonidae family. It has adipose fin and the tail fin has a deep notch. The fish is special for fresh and cold north waters and are mainly found in north hemisphere and north of Europe, Asia and America. It feeds aquatic invertebrate and zooplanktons. The mentioned species has tasteful meat and supplies the major part of fish consumption. The big fishes meat is tasteful, low fat and has a cucumber like odorous characteristics and is mostly consumed in dried and smoked forms. Since this fish is important in inland fisheries and is releasable and developing in water sources of lakes behind dams has been considered and respect to purity of water resources behind dams. In the lake of Karaj dam has been considered as the only habitat and considered to have to low biological information from October to late march 2001 for 6 months totally 82 samples were caught and studied and through this way lack of fishing in the region by determining 11 stations, the samples were collected and grown, relation between length and weight, age and length, propagation, nutrition and fertility parameters were evaluated. Most of caught fishes are 4 to 5 year olds and 3 and 4 year olds. The 4 year olds males were majority and 5 and 6 year olds females formed the dominant group. Correlation relation between age and total length in both sexes (male and female) was very significant at 1% level, of course in females the correlation was around 100%. The weight and total length in males and females that was caught both had high correlation at 1%level; of course this correlation in females had been very stronger than males. % level related to gonad weight and sexual evolution stages of females. Gonad had correlation at 5 The most absolute fecundity had belonged to 5 year old female with 19120 ovules and the lowest to 4 year old breeder. With 11496 ovules the most relative fecundity was 62.13% and belonged to 5 year old breeder and the lowest was 36.06% belonged to 4 year old breeder by increasing the quantity of ovules in breeders the sixth stage of sexual evolution the fecundity rate has been directly increased as well. % of Gonad weight was the most effective factor on absolute fecundity and according to (R2) more than 90 variations of breeders; absolute fecundity is claimable by their gonad weight. Among all traits, affecting gonad weight fecundity the breeders sexual evolution stage has been recognized the most effective factor on fish ovules diameter. Generally in oligotrophic aquatic resources they become mature before the age of 3 and in utroph aquatic resources and full of edible zooplanktons they become mature with 2 years of age. In respect to nutrition this fish eats a broad range of zooplanktons separated from surface to bed of water of dam lake and no kind of selection was seen there so that in different ecological condition it can differ appropriately to kind of foods available in different seasons so that in cold months (December to March) the food diet of this fish varies toward eating water bed living things such as tobifex. Iranian Fisheries Science Research Institute Published

Some reproduction characteristics of keeled mullet, Liza klunzingeri, were studied during Apr. 2003 to Feb. 2004 in Khuzestan waters of the Persian Gulf. A total of 836 samples were monthly collected from two fish landings of Bahrekan and Hendijan; 727 specimens were studied from point of sex determination, and 60 specimens were studied from the fecundity point of view. This species was found to have more abundance in autumn (esp. Oct-Nov). The samples composed of 89 (12.2%) male, 467 (64.2%) female and 171 (23.6%) immature; the sex ratio was M:F = 1:5. The advanced stages of maturity (4th & 5th) were found in October onward. The highest Gonadosomatic Index was in December and the lowest was in June. The maximum absolute and relative fecundities were 183040 and 2232, respectively; the minimum absolute and relative fecundities were 44700 and 582, respectively. The minimum and maximum egg diameter was 0.04mm (stage 2nd) and 0.75mm (stage 6th).

Fishing vessels equipped with bottom trawls cause high amount of by-catch and discards. We investigated the catch composition and by-catch percentage in October - November 2002 during shrimp fishing season in Hormuzgan Province waters. The studied area was located in DarmSoorkh area, east of Hormuz Island and Toola area. Sampling was done using wooden fishing dhows. During shrimp season, 36 hauls with a total catch of 6050kg were treated. The catch composed of 88 species belonging to 50 families of which 67 species were bony fish from 38 families, 9 species were cartilaginous fish from 6 families, and 3 species were mollusks from three families and also 9 species of crustacean were found belonging to 3 families. The percentages of different groups of by-catch and target catch (shrimp) were 49.4% small discards, 18.7% large discards, 4.7% commercial species and 27.2% shrimp. The ratio of total by-catch to shrimp was estimated to be about 2.7 times that of the shrimp.

The age structure of John's Snapper (Luyanus johni) in Hormozgan waters, south Iran was studied. We conducted monthly sampling starting in May 1996 and ending in July 1997. Totally, 613 fish specimens were collected, of which 567 and 308 specimens were aged based on whole and sectioned otoliths respectively. The snappers were found to be aged from I to 17 years old. Results showed that each year only one pair of opaque and translucent zones was formed. Age determination based on the two methods was significantly different especially in the fish aged 1 to 6 years (P

Some reproduction characteristic of Liza klunzingeri were studied during one year period in 2003. ... Iranian Fisheries Science Research Institute Published

The spawning season, fecundity and Lm50% of the Caspian Sea prawn (Palaemon adspersus) were investigated in the coastal waters of Guilan province. A monthly sampling was conducted using a bottom trawl with mesh size 3 mm in cod end in areas 0-5 and 5-10 meters deep during the year 2002. Mean total length, carapace length and weight of ovigerous female of Palaemon adspersus were 51.95±3.1 mm, 13.95+1.9mm and 2.742±0.58g (X ± S.D). Minimum and maximum total length of ovigerous specimens were 37 and 59.3mm with a weight 1.002 and 4.145 grams respectively. We found that the spawning season of Palaemon adspersus begins in April and ends in September with a peak in June. Mean fecundity of the species was 1994.5±506.6. The size at which 50% of females are mature was estimated to be 51.27mm total length.

In conformity with programming to harvest from virgin resources of Myctophids (Benthosema pterotum) in the Oman Sea (Iranian waters), a series of research cruises and trial fishing were carried out from 1992 to 1998. Assessment of B. pterotum stocks was carried out using the data obtained from a series of seven cruises conducted by R/V Ferdows1 in the Iranian waters using modern scientific echo sounder of EK500 system in 1993-94, with complementary monitoring surveys in the following years. The biomass estimates ranged from 1 to 4 million tones with an average of 2.3 million tons. A number of fishing operations using mid-water trawls were also performed in 1994-1998 using the same vessel. Distribution of B. pterotum was found to be all around the Oman Sea. The dense schools of this species were found in the northwest areas of the Iranian waters. Also the F/V Jahad Fanoos was applied during 1994-95 to do some trial fishing and its maximum catch was 50 t/h.

This research was conducted to identify Cuttlefish population (Sepia pharaonis) in The Persian Gulf and the Oman Sea using PCR-RFLP. Specimens were collected from 15 different stations. Bottom trawling method was used for sampling from different zones of the Persian Gulf and the Oman Sea, and finally 20-40 specimens from S.Pharaonis were collected at each station . DNA was extracted by phenol chloroform method. One pair primer was designed based on 18s rRNA gene nucleotide sequences. The results obtained from 18s rRNA gene RFLP, which was reproduced by PCR technique, were analyzed and utilized for study of diversity of the Cuttlefish population . PCR product with 502 pair base in length achieved for all specimens, which was subjected to enzymatic digestion by 8 restriction action enzymes: Alu I-Taq I-Mnl I- Rsa I-Hind III-Dra I-Pvu II and Hae II DNA bands patterns in all specimens digested by those enzymen showed similarity with no any polymorphism. From this result, it can be concluded that there is not any possibility to isolate different populations in the studied Cuttlefish species under exploitation of rRNA gene. Iranian Fisheries Science Research Institute Published

Psettodes erumei is the sole fish species belonging to Psettodidae family that lives in the Oman Sea. The species has a flat body and is thicker than other flat fishes. It has a large mouth with strong teeth and gray-brown color on body surface; and is mostlysround in muddy-sandy substrates up to 25m depths. The species is carnivorous and feeds on prey fishes. The common trawl and gillnet are commonly used for catching the fish. This study was carried out in the Oman Sea in 2002 covering 86 trawling stations. After each haul, the trawl was emptied on board for separation, identification and weight measurement of the catch items. The CPUA was calculated by Swept Area method and used as an index for distribution analysis of the fish species. The maximum snout-length was found to be 66cm for the study area and the length-weight relationship was calculated as W = 0.0294TL^2 7973.

Jajroud river with 140km length, inhabits various species of aquatics of which one of the main identified one is freshwater crab belongs to POTAMIDAE family with scientific name of Potamon persicum. In this study, 388 specimens from 5 sampling stations (Latian dam, Taraghion, Khojir, Giahan daroie and Mamloo dam) were collected since November 1998. All samples were transferred to the laboratory for reproduction studies and determination of spawning season, with studying the maturity stages of gonads and external eggs. The results showed that the spawning season of this species occurring in middle of spring, it was also found that P. persicum is a total spawner. The external maturity (of eggs) was classified to 7 stages. On the other hand the maturity stages of gonad was recognized in accordance with the color, size and egg diameter and classified to 5 stages.