Past, Current and Future of Fish Diversity in the Alakol Lakes (Central Asia: Kazakhstan)

The aboriginal ichthyofauna of the Balkhash basin consists mainly of endemic fish species. By the end of the last century, indigenous fish species were driven out of Lake Balkhash and the Alakol Lakes remain the largest refuges of aboriginal fish fauna. Knowledge of regularities of the modern distribution of the indigenous fishes is crucial for biodiversity conservation as well as restoring aquatic ecosystems. The modern diversity of fish species was investigated there in this study. Significant changes for the indigenous and some alien fish distributions were revealed in contrast with earlier known data. Canonical correspondence analysis (CCA) was used to study the relationships between habitat characteristics and species abundance. Water mineralization and maximal observed water temperatures were estimated as the main environmental variables in fish distribution at the local scale. Habitat change leads to fish fauna homogenization as a result of rare species extinction and alien penetration. Growing human population and poor water management make the future of the indigenous fishes unpredictable.

Traditional knowledge of the fishermen community of Indian Sundarbans: An assessment of rationality and effectiveness

The present paper describes various Indigenous Technical Knowledge (ITK) of the fishermen community of Indian Sundarbans in West Bengal documented during the period from 2013 to 2015. A total of eleven ITKs were documented including therapeutic value of fish with special reference to small indigenous fishes (SIF) and were categorised based on their uses. Effectiveness and rationality were assessed based on the view of the experts as well as that of fishers. The study indicated that seven ITKs documented were rational and effective. Those valid ITKs include four types of unique fishing methods; fish as special energy booster; methods to support natural fish breeding and fish marketing. Remaining four ITKs, like use of fishes to address unique human health issues, method to reduce mortality during prawn seed transport and behaviour of fish for forecasting extreme climatic events, although appeared as irrational and less effective as per the view of experts, fishers are practicing them and hence demand special attention for proper validation, improvement and popularisation in the context of changing regional resource structure and stakeholders’ needs.

A Review on Embryonic Development of Inland Fishes of Bangladesh

The early developmental pattern of inland fishes of Bangladesh are not well studied though it has a great importance in fisheries and aquaculture sector. The embryonic study provides interesting information on further growth and health of the fish and considered as an essential component for optimization of fish seed production by natural and induced breeding. Therefore, the current review work has been undertaken to provide a detail information on embryonic development of important inland fishes of Bangladesh. Information was collected from published scientific papers, un-published Masters and PhD dissertations from universities, popular articles and other published and grey literature. Diameters of unfertilized egg of the reviewed fish species were found to be 0.5 to 1.3 mm and fertilized egg were 0.49 to 1.6 mm. Shapes of the egg were also variable from species to species. There is little information available on egg activation and egg micropyle of fish species of Bangladesh. The fertilization rate of different fishes ranged from 40.1% to 93.9%. There are different stages of early development in different species and time needs to complete the stages also vary. The timing of post hatching development by metamorphosis was found to vary based on the fish species from several days to weeks. Different factors like temperature, photoperiod, DO, seasonality and presence of chemicals in water were found to affect the early development of fish. The review included eighteen inland fishes and unearthed useful insights of their embryonic development and influence of different factors. As we expect, the outcome of the study would provide a baseline and would be very useful in conducting further research on the embryology of indigenous fishes of Bangladesh.