Chemical ecology fatty acids of mollusks dominant species in intertidal zone of Chabahar Bay

Chemical ecology is the science of study and analysis of natural chemical products in result of biochemical processes in organisms and their reactions to variations of ecological and environmental parameters. In marine chemical ecology the existence of natural products in aquatic organisms and their ecological roles in marine animals and their reactions to environmental parameters variations will be studied. Among them, fatty acids are the most various and abundant ones in natural products which had been extracted from many marine organisms such as mollusks and algae. In this study selected animals were the dominant species of mollusks in intertidal zone of chabahar bay including gastropods, bivalves and polyplacophora classes. Nerita textilis and Turbo coronatus species are among gastropoda, Saccostrea cucullata is from bivalve, and Chiton lamyi is from polyplacophora. After seasonal sampling, separation and identification of natural products of these species, fatty acids had been isolated and identified by GC mass chromatography and their seasonal variations had been identified. In addition environmental factors of the location including pH, salinity temperature, dissolved oxygen, chlorophyll a and nutrients were measured monthly. Then the effect of seasonal variations of environmental factors on fatty acids had been studied by applying statistical analysis. GC/MS resulted thirteen fatty acids, which the most importants were myristic, stearic, oleic, palmitoleic, arachidonic and eicosapentaenoic acids. In majority of species palmitic acid was most abundant than the others and saturatedes had the most percentage levels than unsaturated ones. Although seasonal variations of identified fatty acids was not similar in species, but the majority of unsaturated ones had their maximum during winter, while saturated acids reached their maximum in summer. Statistical Analysis showed the strong correlations between Environmental factors and some fatty acids and temperature, nitrate, silicate and pH had strong correlations in all species. The species was studied from the point of lipid content and the results showed a good quality of lipid content in the selected species in the intertidal zone of Chabahar bay.

The chemical prospectors

The article discusses the results of researches on chemical prospecting of marine organisms containing compounds that show promise as anti-cancer drugs.

Physical and chemical characteristics of major aquatic ecosystems in the Victoria and Kyoga lake basins

The physical-chemical characteristics of any aquatic ecosystem include pH, conductivity, and temperature, water transparency, nutrient and the chlorophyll-a levels. Physical and chemical factors of any ecosystem determine the type and quality of flora present in it and these forms the basis on which the system operates. The elements required in largest amounts for plant productions are carbon, phosphorus, nitrogen, and silicon, which is important for diatoms as a major component of the cell wall. Nutrients may limit algal productivity in the tropics despite the high temperature there allowing rapid nutrient recycling. Nutrients most likely to be limiting African lakes are nitrogen (Talling & Talling 1965; Moss 1969; Lehman & Branstrator 1993, 1994) and phosphorus (Melack.et al l982; Kalff 1983) while silicon may limit diatom growth (Hecky & Kilham 1988). The objective of the study is to investigate the impact of physical-chemical characteristics on the distribution and abundance of organisms in the major aquatic ecosystems.

Physical, chemical, algal composition and primary production in the four Kisoro minor lakes

The study was conducted between 1998 and 1999. Physical, chemical and biological factors of the water quality characteristics were collected and analysed

Monthly patterns in physico-chemical conditions and fish catch in the immediate vicinity of the Bujagali hydropower construction site 29th September - 28th October 2007

The specific objectives were to: WATER QUALITY 1. To measure the water physical variables as indicators of environmental conditions in the upstream and downstream transects of Kalange (1) and Buyala (2), respectively, 2. To determine the concentrations of total suspended solids as a major constituent likely to be released into the waters at any time during the construction activities, by comparing the concentrations at the two transects. FISH CATCH 1. To follow up trends in fish catch as construction activity progresses, and to precision of the estimate; 2. To estimate the prevailing fish catch rates, total fish catches and the total value of the fish catch to the local fishers at the two transects.

Chemical, microbiological and sensory examinations of dried Lake Tanganyika sardine presently marketed in Zambia

Proximate composition, PH, total aerabic counts, coliform counts, appearance and taste of dried Lake Tanganyika sardine (Limnothrissa miodon and Stolothrissa tanganicae) sampled at Lusaka markets were analysed for the period July 1969 to February 1970. Water content for the dried sardine varied between 7 and l4% and oil content between 8 and 14% according to season. Flavour of the cooked sardine was scored as good to fair, which discredits the common belief that is poor in quality. Cooked fish scores correlated poorly to the oil content and bacterial counts of the dried fish.

Chemical, bacteriological and sensory examination of split, dried, smoked bream on the market in Zambia

A critical examination of the market quality of split, dried and smoked bream (Tilapia spp.) was chemically, bacteriologically and organoleptically conducted for the period of August 1968 to January 1969. The aim of this survey was to obtain basic information for the development of national quality standards for the commodity. Relationships of cooked meat score to pH, fish size, appearance and smell score, and water content wcre significantly correlated and responsive. Therefore, these parameters were proposed to be used as indices for the quality standards of the products.