JOURNAL OF MARINE BIOLOGY
Year:2009 | Volume:1 | Issue:1|Papers Count:9

In this study frequency and composition of plankton in Shadegan wetland was carried outin 5 stations during2007-2008. Genus qualitative identification and their composition and quantitative frequency aspect were studied (for phytoplankton chlorophyll a). Frequency of total 42 genus phytoplankton in4 classesBacilariophyceae (Diatom), Cyanophyceae, Chlorophyceae and Dinophyceae are 69.4, 22.22, 10.15 and 5.16 percent respectively and Diatoms are most dominant. In which Cyclotella and Nitzschia genus have the most abundance.In this manner, Frequency of total 24 genus zooplankton 4 groups Rotifera, Copepoda, Protozoa and Cladocera that are 80.47, 17.30, 2 and 0.23percent respectively and Rotifers are most dominant. . Phytoplankton has two frequency peak: first in the summer and the second with less in the early fall. Rogbh and Etysh have the most diversity in all of the stations. Mean annual primary production are1.67 gC/m2/d and maximum and minimum are 4.67 and 0.50 respectively. Absence of indicator species that eutrohic lakes such as Peridinium and Ceratium and none blooms ofCyanophyceae, are rejected the existence of conditions eutrophic. Other evidence, including presence macrophyta, the low water turbidity and high plankton diversity is an indicator of the quality of all of which are relatively natural wetlands. New input waste water agricultural to wetlands can first increase primary production by high nutrients and according occurrence of chaos theory and environmental stress, stress factors, first increase species diversity and in continuation status diversity decreases .

This investigation was carried out  monthly between September 2005 to October 2006 with shrimp trawl that had mesh size of 24 mm in order to recognition, estimate the frequency and distribution of Penaeidae shrimp in Mahshahr creeks (Darvish, Doragh, Ghazaleh,Ghanam, Bi had, Patil and Zangi).A total of 1925 individuals which belonged to 3 species of Penaeidae family were captured. Their mixture composed of Metapenaeus affinis with 60.62%, Parapenaeopsis stylifera with 37.73%, and Penaeus semisulcatus with 6.65%. In this spescies female sex had more frequency than male.Maximum abundant  also existed in June to August 2006 . Ghazleh creek had maximum  abundant  of shrimps . All species were in juvenile and pre-adult stages (had length range 44-129mm). However, based on ANOVA analysis, we observed significant differences between monthly frequency of shrimps (p≤0.05).

Polycyclic Aromatic Hydrocarbons (PAHs) are stable organic compounds that their carcinogenic properties have been proved. This components enter to the organisms body throught  food chain and affect the consumers adversely. This study was conducted in order to consider the effect of water soluble fraction of crude oil on the accumulation of PAHs in muscle tissue of  Pseudorhombus elevatus of The Persian  Gulf. It was performed in spring 2005 in the ecology research center of The  Persian Gulf. Two solutions with 0ppm and 12ppm dosages of crude oil were prepared with Anderson method and seawater. Then 24 fish from this species that were caught randomly from 6 stations of  The Persian Gulf were exposed to 0ppm and 12ppm dosages of crude oil for 8 days in long-term bioassay examination. After 8 days exposed fish were freezed and packed seprately and sent to the laboratory for determination of PAHs accumulated in their muscle. PAHs measurment was done with GC-FID model varian 3400. In this research, the amount of each compound of PAHs was detected. Then total PAHs in each dosage was calculated seprately. The result of data analysis shows that the mean accumulation amounts of PAHs ( x¯ ± STD) in tissues of testifier Pseudorhombus elevatus was 929.66 ± 2.51 ppb. Also the mean accumulation amounts of PAHs (x¯ ± STD) in tissues of Pseudorhombus elevatus which were exposed to 12 ppm dosage of crude oil was 3843 ± 13.52 ppb. According to T-test test we concluded that there is a significant difference (p<0.05) between two mentioned dosages of crude oil from their accumulation point of view in muscle tissues of this species. In other words exposing fish to 12ppm of crude oil can increase the accumulation of PAHs in comparition with testifier fish. On the other hand, the high amount of PAHs in the testifier fishes is due to pollution of The  Persian gulf.

Feeding of Shah – koolee which is one of the economical and popular fish in the northern part of Iran was studied in the area of the Sefidrood river. Carry out this research, 539fish were cought at selected stations from the scashore estuary to Kisum From April to August 2000 Intestinal content of sixty eight speciment in different sizes was collected and after primary biometry, their gastrointestinal system was removed and studied.Relative gut length (R.L.G) was 0.74 and the special charactristics showed that the main food of Shemaya is zooplankton. The vacuity index (C.V) was 23.5 percent Which proves that Shemaya is among greedy fishes.Instestinal examinations of Shan – koolee Shows that Three phytoplanktonal order including Crysophyta, Chlorophyta and Cyanophyta and two zooplankton order including Copepoda and Cladocera were the major food items consumed by this fish in Sefidrood river. In addition, some different organisms bigger than phytoplankton and zooplankton such as Chironmidae larvae and Gomphonaema were in its diet.Studies of Shah-koolee migration in Sefidrood river shows that spawning is more important than feeding.

The present study was carried out growth and mortality Parameters of Hilsa shad in the coasts of Khuzestan province (including Abadan and Hendejan ) using the commercial catch data. Totally more than 13000 specimens of Hilsa shad have been measured during 2007-2008. Population parameters were estimated using FiSAT software program. The growth parameters of von Bertalanffy equation were estimated as, L∞: 54.60 and K: 0.96 and  t0: -0.14. Mortality coefficients such as total mortality, Z: 4.20and natural mortality, M: 1.34 and fishing mortality, F: 2.8 were estimated. Exploitation ratio, E was estimated to be 0.68 and these high values of E showed that the Hilsa shad stock in the region was overexploited. Results showed that exploitation ratio of the hilsa shad stock was over fishing and decreases exploitation ratio proposed. According to biological characteristics and with compare to American Fisheries Society (AFS) indices, Hilsa shad is classified as low vulnerable group fishes.

Abstract In this study, we have investigated the effects of mix of Tomato (Solanum lycopersicum)  & Carrot) Daucus carota ( and red Bell pepper )Capsicum annuum( as a natural pigment source and astaxanthin as synthetic pigment sources on the skin colour of cichlid fish (Astronotus ocellatus sp., Agassiz, 1831), which are generally white with red patches in the dorsal skin. The fish were fed diets containing 100 mg kg–1 astaxanthin and natural pigment. The amount of both natural and synthetic pigment sources given as feed was 100 mg kg–1, and the experiment was continued for 60 days. Total carotenoid content of the fish was determined spectrophotometrically at the end of the experiment. As a result, while a visible change of colour in the skin of the fish fed on the feed containing astaxanthin was observed with 0.43 ± 0.2 mg g–1 of pigment accumulation, a relatively change of colour was observed in the skin of other fish that were fed on the feed containing powder of Tomato & Carrot and red Bell pepper with 0.35 ± 0.2 mg g–1 of pigment accumulations, respectively. Therefore, it was determined that these pigment sources have an effect on the colour of cichlid fish.

Euthynnus affinis with local name: Zardah is an important species in scombrid fishery in the Hormozgan and southern Iran provinces. Catch management of this species in region is requiring to be known some biological parameters such as growth and mortality. In this research according to migration behavior of kawakawa in Hormozgan, Samples were collected from landing at four station: Gavbandy, Kong, Salakh and Jask. During Three years study from 2003 to 2005 more than 25000 specimens were measured, mean ±S.D Values for each year were 64/58±6/27, 64/73±7/2 and 62/96±5/31 respectively. The maximum and minimum total lengths were 25cm and 86cm respectively. Growth and mortality parameters were calculated for the 3 years as below, L∞: 89, 87 and 87 and K: 0.5, 0.52 and 0.53 and t0: -0.30,- 0.46, and -0.48, Z: 1.78, 2.72 and 2.62, M: 0.64, 0.66 and 0.67, F: 1.14, 2.06 and 1.95 respectively. Exploitation ratio (E) was estimated 0.64, 0.75 and 0.74 respectively. Exploitation rate, U : 0.53,0.7,0.68 and Annual total stock at beginning of year: 11566,7881,9060 T and Annual average standing stock , b : 5419, 2678 , 3159 T were also estimated for 2003 – 2005 respectively. Result in this study showed exploitation ratio kawakawa stock is over fishing and decreases exploitation ratio proposed.

This research was carried out in summer 2008 at Abzisytan shrimp aquaculture hatchery center in Bushehr province " Delvar " for 10 successive weeks (2 weeks for adaptation and 8 weeks for culture). The effects of dietary nucleotide at 5 levels of dietary including 0.0%(control), 0.15%, 0.25%, 0.35% and 0.5% on the growth performance of Epinephelus coioides was investigated in this trial. Juvenile fishes with average weight of 10.70 ± 0.29 were fed by experimental diets for 8 weeks. The trial was carried out in 300 liter fiberglass tanks. Fifteen juveniles were stocked in each tank. The best value of growth parameters were observed at dietary at level of 0.35% nucleotide and based on Duncan test, it is recommended that in this study 0.35%  of  nucleotide suitable for growth of Epinephelus coioides.