Himadri Saha

Effects of waterborne iron on fry of Catla catla (Ham.), Labeo rohita (Ham.) and Cirrhinus mrigala (Ham.)

Effects of waterborne iron on Indian major carps (Catla catla, Labeo rohita and Cirrhinus mrigala) fry was evaluated in the present study. In short-term definitive test a concentration series of 8, 10, 12, 14, 16, 18, 20, 22 and 24 mg l-1 of iron were selected. In long-term partial life cycle test 1.0, 2.0, 3.0, 5.0 and 6.0 mg l-1 of iron were selected to observe the behavioural changes, feeding rate, growth rate and bioaccumulation of iron in different organs of fishes. Supplement of iron was done by adding FeSO4 to get the test concentrations. Rohu showed highest tolerance to iron toxicity. The lowest 96 h LC50 value was found for mrigal as 11.21 ± 0.53 mg l-1 whereas the highest was observed in rohu as 16.75 ± 0.96 mg l-1. Among the organs tested, comparatively gill showed higher iron accumulation and muscle showed the lowest. However, rate of change of iron accumulation in gills w.r.t toxicant concentration was lowest as compared to other tissues. Histopathological study of gill showed the evidence of iron accumulation and erosion of secondary gill lamellae. In long-term partial life cycle test reduction in feeding rate, behavioural changes and reduced weight gain was observed. Mrigal showed highest accumulation and catla showed the lowest.

DNA Barcoding of Freshwater Fishes of Indo-Myanmar Biodiversity Hotspot

To develop an effective conservation and management strategy, it is required to assess the biodiversity status of an ecosystem, especially when we deal with Indo-Myanmar biodiversity hotspot. Importance of this reaches to an entirely different level as the hotspot represents the area of high endemism which is under continuous threat. Therefore, the need of the present study was conceptualized, dealing with molecular assessment of the fish fauna of Indo-Myanmar region, which covers the Indian states namely, Manipur, Meghalaya, Mizoram, and Nagaland. A total of 363 specimens, representing 109 species were collected and barcoded from the different rivers and their tributaries of the region. The analyses performed in the present study, i.e. Kimura 2-Parameter genetic divergence, Neighbor-Joining, Automated Barcode Gap Discovery and Bayesian Poisson Tree Processes suggest that DNA barcoding is an efficient and reliable tool for species identification. Most of the species were clearly delineated. However, presence of intra-specific and inter-specific genetic distance overlap in few species, revealed the existence of putative cryptic species. A reliable DNA barcode reference library, established in our study provides an adequate knowledge base to the groups of non-taxonomists, researchers, biodiversity managers and policy makers in sketching effective conservation measures for this ecosystem.