Day :
- Fish Physiology
Location: Vancouver, British Columbia, Canada
Session Introduction
Md Faizur Rahman
The University of Texas Rio Grande Valley, TX 78520, USA
Title: Effects of elevated temperature on oxidative DNA damage in the American oyster (Crassostrea virginica)
Biography:
Md Faizur Rahman has completed his Bachelor of Science and Masters of Science from the University of Dhaka and continuing his Master of Sceicnes studies in the School of Earth, Environmental and Marine Sciences at the University of Texas at Rio Grande Valley. He is the life time member of Zoological Society of Bangladesh (ZSB).
Abstract:
Global temperature increases due to natural and manmade emissions of greenhouse gases which affects the terrestrial as well as marine and coastal environments and their biota. The effects of rising sea water temperature on marine and coastal organisms are well documented in teleost fishes. The American oyster (Crassostrea virginica) is an ideal shellfish species to study on global warming and oxidative DNA damage. Gills of oyster seem vulnerable to environmental stress due to their early exposure to sea water compare to other organs. In this study, we used high temperature as a form of environmental stress and measured different biomarkers on oxidative stress and DNA damage. We analyzed heat shock protein-70 (HSP70, a key chaperone protein), 8’-hyrodxy-2’-deoxyguanosine (8-OHdG, an oxidative derivates of deoxy guanosine), single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), caspase-3 (CAS, a master enzyme of apoptosis), BAX, a apoptosis regulator protein; and γH2AX, a sensitive molecular marker of DNA damage; protein expressions in gills of oysters. We also analyzed the extrapallial fluid (EPF, an important body fluid found in marine bivalves which regulates many physiological functions) conditions (e.g. protein concentration, glucose level) in oyster. Oysters were maintained in six glass aquaria with three different temperature groups: control (24oC), medium (28oC), and high (32oC) temperatures for one-week exposure. Immunohistochemical results showed that elevated temperatures (28 and 32oC) increased HSP70, 8-OHdG, ssDNA, dsDNA, γH2AX, BAX, and Caspase-3 protein expressions in gills of oysters compare to control temperature. EPF glucose level also increased, however, EPF protein concentration decreased in heat exposure oysters. Collectively, these results suggest that heat shock driven oxidative stress induces DNA damage which may lead to decreased various physiological functions in American oyster.
- Aquaculture Engineering
Location: Vancouver, British Columbia, Canada
Session Introduction
Siddhartha Regmi
Institute of Forestry, Tribhuvan University, Hetauda, Nepal
Title: Species Diversity threats to Fish Fauna in Adhokhola River, Nepal
Biography:
Siddhartha Regmi is a graduate student at Institute of Forestry, Tribhuvan University, Nepal which is an reknown institution in Nepal. He is also early career researcher, though have appreciative research experiences. He completed his Bachelor’s Degree in Institute of Forestry, Tribhuvan University, Nepal. This conference will help him to achieve his career goal in the field of ecological research
Abstract:
Aquatic biodiversity is in crisis due to several natural and anthropogenic factors. This study was conducted to assess the status and threats to the fish fauna in Andhikhola River system, which originates from a low• mountain in Siwalik. Both primary and secondary data collection methods were used in the study. Primary data was collected by reconnaissance survey and field monitoring and secondary data were collected from literature review from research reports, journal articles and books, records from Department of National Park and Wildlife Conservation (DNPWC), Andhikhola Hydropower Project and other stakeholders and from relevant websites. Seven sampling sites were chosen (sites A-G). All sites were selected based on availability of water resources, stakeholder consultation and the habitat preference of the fish species in that river system. Catch and release method was used in field to find out the diversity of fish. Qualitative and Quantitative analysis methods were used to analyze data. Two orders of fish i.e. Cypriniformes and Siluriformes were found in the area. Under these two orders. 6 families, 26 species and 128 individuals were catch. Both natural threats (silt deposition, flooding) and anthropogenic threats (illegal fishing, construction of dam/bridge. waste dumping and poisoning to fish) to fish were found in the study sites. It is suggested to construct appropriate ladder during dam construction, stop dumping in the river and further study on fish diversity and threats to fish. Also to fulfill gap of knowledge on fish diversity, it is advised to have government plans, so the knowledge on fish taxonomy and conservation could be prioritized giving special focus raising awareness on conservation of riverine fishes.