Search results for: cold-water

Authors: Feroz A. Shah, M. H. Balkhi

Abstract:

The study was aimed at to record the distribution and prevalence of various metazoan parasites of fish from hill stream/coldwater fishes of various water bodies of northwest Himalayan region of India. Snow trout (Schizoth oracids) from eutrophic lakes and fresh water streams were collected from January to December 2012, to study the impact of environmental factors on the dynamics and distribution of parasitic infection. The prevalence of helminth parasites was correlated with available physico-chemical parameters including water temperature, pH and dissolved oxygen (DO). The most abundant parasitic infection recorded during this study was Adenoscolex sp. (Cestode parasite) which showed positive correlation with pH (significant p≤0.05) negative correlation with temperature. The Bothriocephalus was having positive correlation with water temperature while as negative correlation was observed with pH and DO. The correlation between Diplozoon sp. and Clinostomum sp. with the physiochemical parameters were non-significant.

Keywords: hill stream fishes, parasites, Western Himalayas, prevelance

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Authors: Ning Zhang, Kateřina Grabicová, Pavel Horký, Zuzana Linhartová, Jan Turek, Martin Pšenička, Linan Gao, Roman Grabic, Tomáš Randák

Abstract:

Sewage treatment plant (STP) effluent is a significant source of pharmaceuticals and personal care products (PPCPs) in the aquatic environment. Exposure laboratory studies have a limited reporting capacity to capture the complex effect of actual pollution on exposed organisms in the aquatic environment. This study aimed to study the impact of contamination originating from the STP's effluent on early life stages development and sex determination of brown trout (Salmo trutta m. fario) – a native coldwater species with a long period of embryo-larval development – by using special floating egg incubators usually used to support native fish species within fisheries management. Brown trout eggs were placed upstream (the control group) and downstream (the exposure group) of the STP Prachatice situated on the Zivny stream. Up to 72 PPCPs were detected in at least one water sample with higher concentration downstream than upstream. Compared with the control group, the mortality of brown trout in the exposure group was significantly higher; after statistical correction of temperature, the size, growth rate, and metabolic rate of brown trout in the exposure group were significantly lower than those in the control group. After several months of natural growth in the stream, the male-to-female ratio of randomly caught brown trout in the exposure group was 1: 1.9, showing the imbalance of sex ratio. These results suggest that STP effluents can negatively affect the early growth and development of fish in watersheds, and these negative effects may further affect the population density of aquatic organisms and the balance of the whole aquatic ecosystem. The use of floating egg incubators proved to be a promising approach for studying the effect of pollution on the early developmental stages of fish in natural conditions.

Keywords: fish egg incubator, PPCPs, real exposure scenario, STP

Procedia PDF Downloads 28

Authors: N. N. Pandey, Raghvendra Singh, Biju S. Kamlam, Bipin K. Vishwakarma, Preetam Kala

Abstract:

The rainbow trout (Oncorhynchus mykiss) is an exotic salmonid fish, well known for its fast growth, tremendous ability to thrive in diverse conditions, delicious flesh and hard fighting nature in Europe and other countries. Rainbow trout farming has a great potential for its contribution to the mainstream economy of Himalayan states in India and other temperate countries. These characteristics establish them as one of the most widely introduced and cultured fish across the globe, and its farming is also prominent in the cold water regions of India. Nevertheless, genetic fatigue, slow growth, early maturity, and low productivity are limiting the expansion of trout production. Moreover, farms adjacent to natural streams or other water sources are subject to escape of domesticated rainbow trout into the wild, which is a serious environmental concern as the escaped fish is subject to contaminate and disrupt the receiving ecosystem. A decline in production traits due to early maturity prolongs the culture duration and affects the profit margin of rainbow trout farms in India. A viable strategy that could overcome these farming constraints in large scale operation is the production of triploid fish that are sterile and more heterozygous. For better triploidy induction rate (TR), heat shock at 28°C for 10 minutes and pressure shock 9500 psi pressure for 5 minutes is applied to green eggs with 90-100% of triploidy success and 72-80% survival upto swim-up fry stage. There is 20% better growth in aquaculture with triploids rainbow trout over diploids. As compared to wild diploid fish, larger sized and fitter triploid rainbow trout in natural waters attract to trout anglers, and support the development of recreational fisheries by state fisheries departments without the risk of contaminating existing gene pools and disrupting local fish diversity. Overall, enhancement of productivity in rainbow trout farms and trout production in coldwater regions, development of lucrative trout angling and better ecological management is feasible with triploid rainbow trout.

Keywords: rainbow trout, triploids fish, heat shock, pressure shock, trout angling

Procedia PDF Downloads 94