JOURNAL OF AQUATIC ANIMALS & FISHERIES
Year:2010 | Volume:1 | Issue:3|Papers Count:8

Immunostimulants are one of important ways to prevent diseases. In this research, effects of Ergosan on the growth factors such as total length and increasing of dry weight and survival rates in stage of post larvae PL15 in Indian white shrimp (Fenneropenaeus indicus)was studied. The effects of Ergosan (0.5%) (T1) Ergosan (1%) (T2) Ergosan (2%) (T3) along with a control treatment for comparison was used. Taking into consideration of 4 treatments and 3 replication for each of them, 12 similar vessels were used, which in amounts of 10 liters were refilled with water and reserved with 100 larvae in liters in zoa stages and were fed in a completely randomized design. Duration of experiment was zoa stage to PL15 that in the end of 25 days for the biometry and determination of survival rates were studied. Results showed that the highest amount of total length (mm) observed in PL15 stage in T3 (17.45, 17.42, 17.15) which had a significance difference in regard to the control treatment (16.86) at P<0.05 level. The highest amount of dry weight (mg) observed in PL15 stage in treatments respectively (2.92, 2.93 and 2.85) that against of control treatment (2.75) had a significance difference (P<0.05).The highest amount of survival rates (%) observed in T3 (79.67, 76.33 and78.33) that against of control treatment (60.33) had a significance difference (P<0.05). The use of this product in a desired feeding program from zoa stage to PL12 could increase the resistance and immunity in post larvae as increasing in amount of survival rates and growth factors in shrimps that led to produce suitable post larvae for introducing into the training ponds.

Coastal waters of Persian Gulf were investigated for the purpose of selecting the best place for artificial reef installation in the center and west of Hormuzgan province. In this study, Ichtyoplankton communities were studied seasonally. For this purpose, from the south of Qeshm Island to Hendorabi Island were divided to 10 transects, and each of them was partitioned to 3 subtransects (Coastal line to 10, 10 20 and 20 30 meters), and random sampling was used for data collection. In this study, were recognized 7 families of ichtyoplanktons (Sparidae, Gobidae, Seaniadae, Soliadae, Mugaliadae, Clupaidae and Bregmacerotidae). The results of One Way Variance Analysis for frequency of ichtyoplankton, was showed difference in west area (from Bandar Lengeh area to Bandar Haseneh area and Kish island area) with central area (Qeshm island area) (P<0.05), but in the west area do not differ between from Bandar lengeh to Bandar Haseneh and Kish Island area) (P>0.05). Also, the result of this test was showed ichtyoplankton frequencies had differed in some transects and seasons (P<0.05). Although, these communities had fluctuation, coastal waters of Hormozgun province in this area have appropriated for installation artificial reefs.

This study was carried out from July to October of 2004. Culture of shrimps was done with cooperation of Persian Prawn Company in 3 hectare earthpounds with density of 180000 PL15 in a time period of 127 days in shrimp culture site of Tiab. Some physicochemical factors were measured such as dissolved oxygen, salinity, pH and temperature (morning and afternoon) and transparency (only afternoon) twice per month. Biometry of shrimps also done twice per month. Some physicochemical factors were measured such as dissolved oxygen, salinity, pH and temperature (morning and afternoon) and transparency (only afternoon) twice per month. Biometry of shrimps also done twice per month. the results showed which mean shrimp growth and daily shrimp growth rates and also total production in monoculture system of P. semisulcatus were 13.8 gr, 0.1 gr, 1045 kg respectively.

In this study we was carried out mercury concentration in liver and Muscle tissues of two flat fish species, Euryglossa orientalis and Psettodes erumei, in different station and different fishing areas( Bandar-Abbas and Bandar-Lengeh) in Hormozgan Province. Immediately after the collection, fish samples were stored on ice in an isolated box and transferred to the Environmental Laboratory, Body weight and length of fishes were measured and then dissected the tissues, dry and then powder samples. We analyzed total Hg concentration of liver and muscle tissues by Mercury Analyzer (model LECO AMA 254). The average concentration of total Hg in edible Muscle tissue of deep-Flounder was measured in Bandar-Abbas and was found to be 18.92 and it was 10.19 µg.g-1 in Bandar-Lengeh. The corresponding values for Oriental sole were 8.47 and 0.08 μg.g-1. The average concentration of Hg in liver tissue of deep-Flounder, in Bandar-abbas was 25.49 and that in Bandarlengeh was 12.52 μg.g-1.the values for Oriental sole were 11.88 and 3.2 μg.g-1 in Bandar-Abbas and Bandar-Lengeh, respectively.

Threadfin bream (Nemipterus japonicus) is one of the most important commercial fishes in the Persian Gulf. Speciments were collected from commercial catches from November 2005 to Agust 2006. A totally 473 individual were studied, diet results showed that britle stars were dominant diet with 31%, other food component were small crabs 19%, digested fishes 19%, Echura and Sipuncula 15%, Squila sp. 12%, Shrimps 3% and anchovies 1%. The food items in <14 cm length class Britle stars 50%, in 20-15cm length class small crab 24.6%, in 21-26 cm digested fishes 18.5%, and >26 cm length class Britle stars 50% were dominat. The vacuity index was estimated 53%, that showed this species was mediat-voracious appetite fishes. Britle stars were the major food perfect with 45%, small crabs 37%, Echiura 33%, Squila sp. 28% and others were less than 10 percent. Results on seasonal food items frequecy showed that Small crabs 38.5%, Britle stars 45.3% and 44.6% were more frequent items in summer, autumn and winter respectivly.

This study was conducted from February-March to June-July 2007. As a result, 1188 pieces of 435(kg) fish, belonging to 25 species and 11 families were in the inspection of Trap (Gargoor) 10 times. The most abundant species were in March with 54.0% and the lowest were in April with 7.2%. More than 38.1% of the catches number belonged to (Carangoides talamporoides) and other species Argyrops spinifer 21.9%, Pomadasys kaakan 11.5%, Acanthopagrus latus 7.7%, Epinephelus coioides 6.1%, Carangoides chrysophrys 3.7%, Nemipterus japonicus 3.0% and Lutjanus Malabaricus 2.1% respectively. Totally, numbers of fishes were 94.0% belonged to only 8 species. 24.3% of the catches weight belonged to, Pomadasys kaakan and other species Epinephelus coioides 16.8%, Carangoides talamporoides 16.2%, Argyrops spinifer 13.5%, Carangoides chrysophrys 8.7%, Acanthopagrus latus 7.4%, Lutjanus Malabaricus 3.8%, Acanthoparus cuvieri 1.8%, Nemipterus japonicus 1.6% and Protonibea diacanthus 1.3% respectively. 95.5% totally weights of fishes were belonged to only above 10 species. The average catch per unit effort or one trap month (CPUE) were estimated to be, 1.8 (kg/month), while the Max CPUE in May equal 3.8 and min in March equal were 0.8 kg/month trap.

In this study to achive the best grows condition rotifer Brachionus two treatment (temperature and feeding algae) selected. Studies were performed in October 2009.The rotifer was cultured at tree temperature ranges (25, 30 and 35 ºC) and feeding was with two species of microalgae including, Nannochloropsis spp., Chlorella spp and mixed of Chlorella spp.& Nannochloropsis spp and for comparison among treatment, two–way ANOVA was used. The result showed that with increasing temperature, rotifer density increased. The lowest density of rotifer was observed at 25 ºC and the highest density was observed at 35 ºC. There was a significant difference between the density in different temperatures (P<0.05). In the other words, in this study, some of treatment temperature and nutrition on growth has effected on rotifer. In general the result showed that the temperature of 35oC and with a combination of Nanochloropsis and chlorella the heist density was observed.

Sind sardine is one the most important commercial resources in the Oman Sea (Jask area). In this study the Growth parameters and mortality rates of sardiella sindensis were estimated by monthly length frequencies samplings from commercial fishing purse seiners. This study conducted from Sep. 2008 to Jul. 2009. A totally 4606 specimens were measured for length frequency analysis.The growth parameters of K and L ¥ were estimated 1.4y-1 and 20 cm respectively. The mean, minimum and maximum of total length were recorded 15.7, 9.5 and 19.9 respectively. The t0 and maximum age were estimated -0.17 and 2.5 years. The Von-Bertalanffy growth equation was L(t)=20 (1-exp (-1.4 (t+0.17), with two recruitments per year and the maximum recruit were found in September. The Length-Weight relationship was BW=0.0131TL2.8328. The total mortality (Z), natural mortality (M) and fishing mortality (F) were estimated 3.15, 0.72 and 2.43 per year, respectively. The exploitation rate (E) was 0.22 and it was significantly low and it showing the under exploitation of sardine resources in the study area and it is proposed to increase the fishing effort with encouraging the traditional fishermen to be more involved in this fishery.