Search

The species Lepidocephalus thermalis is commonly called as Indian spiny loach and locally called as Ayirai meen. It is widespread in peninsular India and Sri Lanka. Loach is edible freshwater fish and its preferred food fish in southern part of Tamil Nadu. It consists of nutraceutical potential with good taste and flavor and it's rich in calcium, irons and other nutrients. In many places, this species is being used and consider as ornament value but, in this state, it is considered as better taste inland fish so it has to fetch good price all-around in the local market. Loach has inhabitant in ponds, lake, streams and adjacent creeks of paddy fields. A species diversification is takes place important role in inland fish culture at India.

A 330-day field trial was conducted to evaluate the effect of stocking density and feeding ration on stunted Labeo rohita (Hamilton, 1822) fingerling reared in floating net cages. The stunted fingerling of L. rohita with an average body weight 38.23 ± 1.90 g were stocked in cages (3 × 3 × 3 m) at different densities viz. T1 (10), T2 (15), T3 (20) and T4 (25) fish/m3 and fed with varying levels of feeding rations at 3, 4, 5 and 6% at each stocking density. The 4×4 factorial design was used, and each density and feeding level kept in triplicate, and fed with commercial pellet feed (crude protein 28% and fat 5%) twice in a day. The significant recovery was observed in the T1 (10*5 and 10*6) treatment groups, which showed highest Hb, RBC, PCV and lowest WBC content at the end of experiment. Similarly, significant changes were observed in glucose, cortisol and lactate dehydrogenase (LDH), which were highest in higher stocking density (T4), and normalized in lower stocking T1 (10*5 and 10*6) treatment groups. Histological examination showed, almost complete recovery of structural changes such as swelling/ edema primary lamellae, hyperplasia of basal epithelium between the secondary lamellae of gill and necrosis in liver of lower stocking densities (10 and 15 fish/m3). In contrast, greater structural changes in both the organs were observed in the higher stocking density groups (20 and fish nos/m3). Based on the results, it can be concluded that maximum growth and complete recovery (in term of haematology, stress and histological changes) were observed in lower stocking density (10 fish/m3) fed with 5 to 6% feeding levels. Hence, in an Indian reservoir cage-based cultures, 10 fish/m3 fed with 5 to 6% feeding rations can be recommended at commercial scale to get maximum and sustainable profit by using the stunted L. rohita fingerling.

The purpose of this review is to elucidate the antimicrobial effect of seaweed extracts as a dietary supplement in aquatic animals. Aquaculture, a future of food producing sector, plays an important role in global food security, elimination of mal nutrition, and provides livelihood and employment over 59 million people around the world. Though, one side global food fish production and consumption shows an increasing trend, on the other side due to the over exploitation of available marine resources and emergence of deadly bacterial and viral disease in culture practices, the sector is leading to a great adversity which can bridge a gap between fish production and consumption. Nowadays there are several chemicals and drugs have been used to treat the diseased aquatic animals. Antibiotic usage in aquaculture practices, to mitigate the pathogenic intruders, is unsustainable and its application makes the bacteria to evolve resistance and their consumption leads to food vulnerability in human and animal. Presently, the global fish production sector is moving towards the sustainable and eco-friendly solutions to mitigate the emerging deadly intruders. However, there are many sustainable alternatives in practice such as, bacteriophage therapy, vaccine, RNA interference, use of short-chain fatty acids and polyhydroxyal kanoates to inhibit the growth of bacterial intruders, use of immune stimulants, probiotics, prebiotics, symbiotics, quorum sensing inhibition, and also the use of seaweed extract in the place of antibiotics and chemicals considered as an effective and sustainable alternative in fighting against the diseases in aquatic animals. Extracts derived from seaweeds, exerts numerous benefits over the cultivable aquatic animal which includes, promotion of growth and enhancement of the immune and other physiological performances. The present review gives an insight to the use of bio-active compounds derived from seaweeds and its beneficial effects to improve the production and immune status in aquatic animals.

Petroleum products, such as gasoline, leaked from an underground storage tank can be recovered successfully by two-pump operations. The success of the recovery effort depends on the accurate placement of the recovery well at the spill site. An effective recovery operation can minimize the remaining contamination mass in the subsurface. Therefore, a careful evaluation and determination has to be made as to where to locate the recovery well. The location of the well can be decided based on an estimation of the extent and thickness of free product on the water table. Such an estimation should be based on analysis of governing mechanisms. In this study we present analytical solutions to estimate the recovery of oil from an established oil lens. These solutions are obtained by applying the Laplace transformation to averaged linear partial differential equations governing the phenomenon. The governing equation for the free product thickness is derived by averaging the oil phase mass balance equation along the free product thickness and substituting the boundary conditions at the oil/water interface and oil surface. The analytical solutions estimate the temporal and spatial distribution of free product thickness on the water table for a number of recovery scenarios. Results are presented for the temporal and spatial variation of the free product thickness, temporal variation of the free product Volume recovered, and recovery efficiency based on the readings at the monitoring wells. Since they can be utilized without a great deal of data, analytical solutions are quite attractive as screening tools in two-pump free product recovery operations.