JOURNAL OF WETLAND ECOBIOLOGY
Year:2010 | Volume:2 | Issue:3|Papers Count:9

In this study, sedimentary mollusks were collected by Peterson grab with covering area of 225 cm2 from three stations with 3 replicates in each from along Shadegan wetland. Samples were fixed on formalin 5% and transferred to laboratory for further determinations .Based on the result, 5 genera belonging to 5 family, 3 order and 1 class were identified. Mesalia sp. and Pirenella sp. were reported for the first time from Shadegan wetland.In this investigation, the diversity of mollusks were reported very low.

This study carried out during January 2006 to August 2007. Tagging and biological measurements were done on 42 pieces of Hawksbill turtle. The following parameters : sizes of straight length, width of carapace, length of tail, reproductive parameters such as total laid eggs, the number of normal and abnormal eggs, weight and the diameter of eggs were measured. Analysis on the soil types of different nesting sizes and successes in nesting of the eggs showed that Nakhielo Island was a suitable main land for nesting of Hawksbill turtles with fine soil particles. The average weight and straight length size were 49.45 Kg and 65.12 cm, which in comparison with Hawksbill turtles in other parts of world, were smaller. The total average number of eggs were 92 and the mean diameter and weight of eggs were measured as following: 37.18 mm & 30.45 gr that was similar to the same species in other countries along the Persian Gulf but in comparison with same species in other parts of the world was so smaller in size. The results showed that the Hawksbill Turtle population nesting in Iranian coasts, were similar to the same species in other countries along the Persian Gulf, but had larger eggs diameters and larger new borne turtles that leaded to higher survival rate of this species in Nakhielo and other Islands of the Boshehr Province.

In this study, in order to investigate limnological and biological parameters of Lar dam lake such as indentification of density and distribution of phytoplankton, sampling were done during 6 months from different depths (layers 0, 5, 10, 20, 30m) by Ruttner and fixed in formalin 4% and transferred to laboratory for further investigation under inverted microscope. In this study, 28 genera which belonged to 6 phytoplanktonic phylla were identified. Among these genera, 14 were belonged to Bacillariophyta, 1 genus was belonged to Euglenophyta, 7 genera were belonged to chlorophyta, 3 genera were belonged to phyrophyta, 1 genus was belonged to chrysophyta and 2 genera were belonged to cyanophyta. In this reservoir dam, Bacillariophyta was the dominant phytoplanktom phylum with annually 74.83% of population and following genera cyclotella, Navicula and Nitzchia were dominat samples. The others phytoplank tonic phylla were: chlrophyta, chrysophyta, Pryophyta, Euglenophyta and cyanophyta with following frequencies: 17.10%, 3.60%, 2.73%, 0.83% and 0.83% respectively and following genera: (Oocystis, Padiastrum, Scendemus and Chlorella), (Dinobryon and Malomonas), (Ceratium and Peridinium) and (Occillatoria and Anabeana). In all of the sampling months, the highest average density was belonged to Bacillariophyta with 437500±37.740 number per liter and the dominant genus of this phyllum which was observed in high number during a year was cyclotella. After that was Chlorophyta with average number of 268750±39.753 per liter and its dominant genera were Oocystis, Pediastrum, Scenedesmus and Chlorella respectively.According to non-parametric analysis Kruskal-Wallis and Mann-Whitney, there were statically significant difference (P<0.05) between Phytoplanktonic frequency in different stations and months but there was not observed any statical significant difference between different depths (P>0.05).Biological studies indicated that this reservoir had low Planktonic generation potential.

In this study, inorder to determine physical and chemical properties and measure following heavy metals concentration: Cd, Cr and Pb, water and sediments samples were collected from 5 stations along Sefid-Rud river in autumn and winter 2009-2010. Geographical maps, topography and land useage of areas along the river were determined by Geographical Information System (GIS). The results showed that heay metals concentration (Cd and Pb) were recorded near or higher` than standard level in water samples of Garjeh station and in the sediment of this station, following heavy metals Cr and Cd had the highest level. In this study, industrial activities, Urban and domestic sewage discharge were determined as the main source of Cd and Pb in the sediments. The extracted organic matter from water samples indicated that in addition to petroleum hydrocarbons existence in water,some unknown organic substances with high concentration were peresent in industrial effluents related to organic materials. Based on the GIS maps, geological structures had no role in contaminating of the river.

The effects of climate change and changes on snowmelt runoff timing is very important in the rivers with snowmelt runoff regime. In this study the snowmelt runoff model (SRM model) and world climate change model (ECHAM4 model) are applied in order to study the effects of climate change on snowmelt runoff timing with two scenarioes (A & B) for next 50 years (2000-2050) in dez basin in the southwest of iran. Research results showed that the peak time of snowmwlt runoff will change from spring to winter and the winter streamflow is going up and the spring stream flow is going down. The summer stream flow is going down slightly and the atumn stream flow will not change considerably.

The embryonic and pre-larval development of Barb (Barbus grypus) was investigated in the reproduction center of endemic fishes in khouzestan province. The fertilization and hatching percentage of egg were 85% and 75%, respectively. Microphile pore in oocytes was similar to the peak of volcano or stoma of plant body and average diameters of oocytes was 2.18±0.16 mm. Eggs with a chorion were spherical, transparent, a little adhesive and without an oil globule and the average diameter of fertilized egg was 2.44±0.06 mm. The first cleavage occurred after 170-200 min and egg incubation and larval development took place after 61 h 30 min. The length of larvae with spoon shaped yolk sac was 7.96±0.25 mm. Open mounth and two chamber swimming bladder were observed in larvae after two and five days of development, respectively.

This study was carried out to determine the health status of four following Aquarium fish species in Ahvaz: Carassius auratus, Astronatus ocellatus, Hypostomus plecostomus, Poecilia reticulata. For this purpose during 1 year, 120 fish (each species 30 specimens) were transferred to the laboratory and examined. Each fish was inspected and examined by routine methods. The parasitical infection was studied by sampling from the organs. The infestation rate in Gold fish was 100% and all 30 fish were infected by at least one type of parasites. In this species the infestation rate from trematoda, protozoa and crustacean parasites were 80%, 66% and 6% respectively. In Astronatus ocellatus the infestation rate was 90% (90% trematoda and 72% protozoa). In Poecilia reticulata the infestation rate was 50% (23% trematoda and 13% protozoa and 13% crustacae). In Hypostomus plecostomus the infestation rate was 60% (60% trematoda and 13% protozoa). In this study following protozoa were detected: Ichthyophethirius sp., Cryptobia sp., Trichodina sp., Myxobolus sp., Lerneae, Hexamita and Dactylogyrus sp.

his study was carried out in the shrimp ponds in the Abadan (Choebde area) during 2004-2004. In this research, rain bow trout fingerling larva were Cultured in 4*4.5*1.5 m pens which were located in 2500 m2 ponds. In each pen, 7000 specimen finger ling larva were released and fed with following foods: FFT1, FFT2 and GFT1 and after reaching to 100gr weight, fishes were deliverd to the open area of the ponds. Based on the results, Survival rate and food conservation rate (FCR) were measured 86.7% and 1.59 respectively.