Distribution of fish in river is controlled by physico-chemical properties of the water which is affected by land-use complexity and intensity of human intervention.A study on fish distribution was carried out in the upper Citarum River to map the effects of physio-chemical properties on habitat use. A survey was conducted to collect fish and to measure the water quality both on dry and rainy season. The result showed that distribution of the fish, in general, represented their adaptive response to physico-chemical properties. The river environment could be grouped into two categories: (i) clean and relatively unpolluted sites, which associated with high DO and water current, and (ii) polluted sites characterized by low DO, high COD, BOD, water temperature, NO 3 , PO 4 , H 2 S, NH 3 , and surfactant. Fish inhabiting the first sites were Xiphophorus helleri, Punctius binotatus, Xiphophorus maculatus, and Oreochromis mossambicus. Meanwhile, the latter sites were inhabited by Liposarcus pardalis, Trichogaster trichopterus, and Poecilia reticulata. Knowledge about fish distribution in association with the pysicochemical properties of water is crucial especially for the river management.
Severe river pollution creates a stressful environment for aquatic organisms, causing disturbances to their health and leading to their extinction. Thus, in this study, the stress responses of tolerant (Oreochromis niloticus) and sensitive (Cyprinus carpio) fish to river pollution in the Citarum River, Indonesia were investigated. The two groups of fish were exposed to varying levels and lengths of water pollution, their blood was sampled, and stress responses were identified. The red blood cells (RBC) count, haemoglobin (HGB), haematocrit (HCT), white blood cells (WBC) count, blood glucose levels, and derived haematological indices such as mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC), were measured. Significant changes in these indices, with tendential changes in RBC and HCT, were observed, indicating that stress responses had occurred in both groups of fish. The sensitive fish recorded more pronounced changes in their haematological activities, with greater amounts of blood parameters being altered in response to water pollution exposure. This result suggested that the sensitive fish were more susceptible to environmental stressors and were, therefore, more vulnerable to extinction in a polluted natural environment.
The productivity of vegetable crops is constrained by insect pests. The search for alternative insect pest control is becoming increasingly important and is including the use of plant-derived pesticides. Plant-derived pesticides are reported as effective in controlling various insect pests through natural mechanisms, with biodegradable organic materials, diverse bioactivity, and low toxicity to non-target organisms. An antifeedant approach for insect control in crop management has been comprehensively studied by many researchers, though it has only been restricted to plant-based compounds and to the laboratory level at least. Nano-delivery formulations of biopesticides offer a wide variety of benefits, including increased effectiveness and efficiency (well-dispersion, wettability, and target delivery) with the improved properties of the antifeedant. This review paper evaluates the role of the nano-delivery system in antifeedant obtained from various plant extracts. The evaluation includes the research progress of antifeedant-based nano-delivery systems and the bioactivity performances of different types of nano-carrier formulations against various insect pests. An antifeedant nano-delivery system can increase their bioactivities, such as increasing sublethal bioactivity or reducing toxicity levels in both crude extracts/essential oils (EOs) and pure compounds. However, the plant-based antifeedant requires nanotechnological development to improve the nano-delivery systems regarding properties related to the bioactive functionality and the target site of insect pests. It is highlighted that the formulation of plant extracts creates a forthcoming insight for a field-scale application of this nano-delivery antifeedant due to the possible economic production process.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.