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The purpose of this study was to understand and compare profitability indices of tilapia production under monoculture, polyculture, and integrated culture models. The study covered a total of 47 tilapia farmers in Guangdong, Guangxi, Fujian, Hainan, Yunnan provinces in the southern coastal areas, and Hebei province in Northern China. The study focused on two objectives: (i) Socioeconomic and production characteristics that influence tilapia production; (ii) Profitability indices, and breakeven analysis of tilapia production using a structured questionnaire. All calculations for the 3 culture models in this study are based on 1mu (667m2 or 0.666 ha). The study found that all tilapia farms visited were owned by males. About 72.9% of the farmers were 30 to 50 years of age; 50% of the farmers had undergone vocational training. Tilapia farm production areas averaged 70.2mu (~4.7 ha) per farmer, and pond aquaculture accounted for 87.5% of their production. Tilapia production costs were an average of US$1168.4 (1 yuan=US$6.6). Positive Gross Margins (GM) and Net Incomes (NFI) were observed. Tilapia production was economically viable with positive Benefit Cost Ratio (BCR) of US$0.24 in monoculture, and US$0.15 in other culture models. Farmers with low yields, especially tilapia cultured in an integrated model were expected to sell fish at US$0.93per kilogram to recover invested capital within a single production season averaging 6 months. Positive Returns on Investment (ROI) of US$0.22-0.15/kg were observed in monoculture and polyculture respectively. In conclusion, the study found that for farmers to increase tilapia production profit margins, tilapia stocking densities need to increase, especially under integrated culture, and improvements are needed in fish feed utilization to reduce current feed conversion ratios (FCR). In order to boost sales, farmers must ensure production of quality fish, and seek alternative markets such as Africa.

The occurrence, types, morphology, and mineralogical characteristics of tube microfossils were studied in gossanites from twelve VHMS deposits of the Urals. Several types of tube microfossils were recognized, including siboglinids, polychaetes and calcerous serpulids, replaced by a variety of minerals (e.g. hematite-quartz, hematite-chlorite, carbonate-hematite) depending on the nature of the substrate prior to the formation of the gossanites. Colonial hematite tube microfossils (~. 150. µm across,1-2. mm long) are composed of hematitic outer and inner walls, and may exhibit a cellular structure within their cavities. Spherical forms are saturated with Fe-oxidizing bacteria inside the tubes - probably analogues of trophosomes. Colloform stromatolitic outer wall surfaces are characterized by the presence of numerous interlaced filaments of hematite (2-3. µm diameter, up to 1-2. mm long). Between tube microfossils, the hematitized cement contains bundles of hematitized filaments with structures similar to the hyphae of fungi. Hematite-chlorite tube microfossils are scattered in gossanites, mostly as biological debris. They are typically 30 to 300. µm in diameter and 1 to 5. mm long. The layered structure of their tube walls is characterized by hematite-quartz and chlorite layers. Abundant filamentous bacteria coated by glycocalix and chlorite stromatolite are associated with hematite-chlorite tubes. The carbonate-hematite tube microfossils (up to 300. µm across, 2-3. mm long) occur in carbonate-rich gossanites. The tubes are characterized by fine (~. 10. µm thick) walls of hematite and cavities dominated by relatively dark carbonate or hematite. Carbonates may be present both in walls and cavities. Stromatolite-like leucoxene or hematite-carbonate aggregates were also found in association with tubes. Randomly oriented filaments are composed of ankerite. Single filaments are composed of individual cells, typically smaller than 100. nm across, similar to that of magneto

© 2016The occurrence, types, morphology, and mineralogical characteristics of tube microfossils were studied in gossanites from twelve VHMS deposits of the Urals. Several types of tube microfossils were recognized, including siboglinids, polychaetes and calcerous serpulids, replaced by a variety of minerals (e.g. hematite–quartz, hematite–chlorite, carbonate–hematite) depending on the nature of the substrate prior to the formation of the gossanites. Colonial hematite tube microfossils (~ 150 μm across,1–2 mm long) are composed of hematitic outer and inner walls, and may exhibit a cellular structure within their cavities. Spherical forms are saturated with Fe-oxidizing bacteria inside the tubes – probably analogues of trophosomes. Colloform stromatolitic outer wall surfaces are characterized by the presence of numerous interlaced filaments of hematite (2–3 μm diameter, up to 1–2 mm long). Between tube microfossils, the hematitized cement contains bundles of hematitized filaments with structures similar to the hyphae of fungi. Hematite–chlorite tube microfossils are scattered in gossanites, mostly as biological debris. They are typically 30 to 300 μm in diameter and 1 to 5 mm long. The layered structure of their tube walls is characterized by hematite–quartz and chlorite layers. Abundant filamentous bacteria coated by glycocalix and chlorite stromatolite are associated with hematite–chlorite tubes. The carbonate–hematite tube microfossils (up to 300 μm across, 2–3 mm long) occur in carbonate-rich gossanites. The tubes are characterized by fine (~ 10 μm thick) walls of hematite and cavities dominated by relatively dark carbonate or hematite. Carbonates may be present both in walls and cavities. Stromatolite-like leucoxene or hematite–carbonate aggregates were also found in association with tubes. Randomly oriented filaments are composed of ankerite. Single filaments are composed of individual cells, typically smaller than 100 nm across, similar to that of magnetotactic

© 2016The occurrence, types, morphology, and mineralogical characteristics of tube microfossils were studied in gossanites from twelve VHMS deposits of the Urals. Several types of tube microfossils were recognized, including siboglinids, polychaetes and calcerous serpulids, replaced by a variety of minerals (e.g. hematite–quartz, hematite–chlorite, carbonate–hematite) depending on the nature of the substrate prior to the formation of the gossanites. Colonial hematite tube microfossils (~ 150 μm across,1–2 mm long) are composed of hematitic outer and inner walls, and may exhibit a cellular structure within their cavities. Spherical forms are saturated with Fe-oxidizing bacteria inside the tubes – probably analogues of trophosomes. Colloform stromatolitic outer wall surfaces are characterized by the presence of numerous interlaced filaments of hematite (2–3 μm diameter, up to 1–2 mm long). Between tube microfossils, the hematitized cement contains bundles of hematitized filaments with structures similar to the hyphae of fungi. Hematite–chlorite tube microfossils are scattered in gossanites, mostly as biological debris. They are typically 30 to 300 μm in diameter and 1 to 5 mm long. The layered structure of their tube walls is characterized by hematite–quartz and chlorite layers. Abundant filamentous bacteria coated by glycocalix and chlorite stromatolite are associated with hematite–chlorite tubes. The carbonate–hematite tube microfossils (up to 300 μm across, 2–3 mm long) occur in carbonate-rich gossanites. The tubes are characterized by fine (~ 10 μm thick) walls of hematite and cavities dominated by relatively dark carbonate or hematite. Carbonates may be present both in walls and cavities. Stromatolite-like leucoxene or hematite–carbonate aggregates were also found in association with tubes. Randomly oriented filaments are composed of ankerite. Single filaments are composed of individual cells, typically smaller than 100 nm across, similar to that of magnetotactic