The successful entrepreneurship of aqua farming relies on the production of aquatic animals in the cost effective, social and environmental friendly approach. Nevertheless, presently fish farming is suffering from various problems related to these. Biofloc technology and/or application of probiotics provide promising results to aquaculture in terms of improvement in the growth and survival of aquatic animals, along with other benefits such as maintaining water quality without causing pollution to the environment. Biofloc is mainly comprised of various beneficial microbial communities, but the action of some probiotics it contains is unknown. On the other hand, probiotics are single, known live microbial strains and their actions to the animals are well established. Therefore, probiotics are recognized for having the most important constituents in the aquaculture. Although biofloc method and probiotics applications are promised to have positive roles aforementioned, the fish welfare often disturbed as the survival of the animals are always less in the fish farming. These led researchers to try generate a new technique to minimize these concerns. Recently new strategy of integrating both biofloc and probiotics were introduced called the exogenous addition of known probiotic bacteria to the biofloc. The study was demonstrated in the area by keeping biofloc as a control. Results promised that addition of single or combination of known probiotics to the biofloc further improve the growth performance of animals in addition with the maintenance of water quality parameters. Besides they also were promising the highest survival to animals with the reduction of pathogenic microbes. An exogenous root of probiotic bacteria on biofloc based aquaculture is a novel approach; relatively less number of studies has been performed in the area. This review describes the impacts of exogenous probiotics on biofloc based fish culture systems.

A sixty-day feeding trial was conducted to determine the ascorbic acid (AA) requirement for growth of striped catfish, Pangasianodon hypophthalmus juveniles. Seven isonitrogenous and iso-energetic (370 g protein per kg and 19.6 MJ/kg) purified diets were prepared with different levels of ascorbic acid such as control (0), T 1 (17.5), T 2 (35), T 3 (70), T 4 (175), T 5 (350) and T 6 (700) mg ascorbic acid (L-ascorbyl-2-polyphosphate) equivalent per kg diet. Fish with a mean body weight of 3.2-3.4 g were stocked (fifteen fish per tank) in triplicates following a completely randomized design. Each group was fed to satiation twice a day for 60 days. Significant differences were observed in growth, survival, body composition and metabolic enzymes activities with different dietary ascorbic acid levels. Maximum weight gain, specific growth rate (SGR) and protein efficiency ratio (PER) were found in fishes fed with 35 mg AA per kg diet, supported by best feed conversion. Fish fed a diet containing vitamin C had the highest activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) compared to those fed with vitamin C-depleted diets.In this study, based on using broken-line regression analysis, the dietary vitamin C requirement for growth of P. hypophthalmus juveniles was estimated to be in the range of 46-76 mg AA per kg, depending on the criterion used, growth and liver storage.Our results will be helpful for the formulation of cost-effective ascorbic acid incorporated diets for striped catfish, P. hypophthalmus. K E Y W O R D Sascorbic acid, growth, L-ascorbyl-2-polyphosphate, Pangasianodon hypophthalmus, vitamin C requirement | INTRODUCTIONVitamin C (ascorbic acid) is considered as one of the essential nutrients required for growth and immunity in fish (Asaikkutti, Bhavan, Vimala, Karthik, & Cheruparambath, 2016;Dabrowski, 2000;Khan, Zuberi, & Ullah, 2015;Lim & Lovell, 1978; NRC, 2011;Pimpimol, Phoonsamran, & Chitmanat, 2012;Xu et al., 2016). Ascorbic acid (AA) has an extensive role in the enhancement of growth, collagen synthesis, iron metabolism, haematology, reproduction, stress physiology, wound healing and immune response in fish (Albrektsen, Lie, & Sandnes, 1988;Anbarasu & Chandran, 2001;Halver, Smith, Tolbert, & Baker, 1975;Roberts, Davies, & Pulsford, 1995). Many of the farmed fishes, such as ictalurids, cichlids and cyprinids, cannot synthesize vitamin C de novo because they do not contain the enzyme, L-gulono-1,4-lactone oxidase (Chatterjee, 1973;Dabrowski, 1994;Moreau, Dabrowski, & Sato, 1999;Xie, Niu, Zhang, & Bao, 2006;Yamamoto, Sato, & Ikeda, 1978). Ascorbic acid is soluble in water, and thus, leaching of this vitamin from feeds can be a serious issue (Abdelghany, 1996; Hilton, Cho, Brown, & Slinger, 1979; Hilton, & Slinger, 1977;Soliman, Jauncey, & Roberts, 1986). Wilson and Moreau (1996) reported that AA is not stable in the native form as 50 mg/kg of the supplemental AA will be destroyed during the feed manufacturing process. Therefore, accur...

This study provides the first record of Lutjanus xanthopinnis Iwatsuki, Tanaka et Allen, 2015 from the Andaman Islands. The new record is based on 2 specimens, 123 and 154 mm SL, captured inshore of Dignabad, Port Blair, Andaman Islands, India. The fish were examined, described, and illustrated. Morphometric and morphological data confirmed that the specimens examined from the Andamans are L. xanthopinnis, which varies distinctly from a closely-related species Lutjanus madras (Valenciennes, 1831).

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Vitamins are vital nutrients indispensable for the proper physiology, metabolism, growth, reproduction and health of aquatic animals (Li & Lowell, 1985). Animals can synthesize certain vitamins from the other nutritional components in the diet, but some vitamins such as vitamin C cannot be synthesized and need an exogenous supply (NRC, 2011). Some primitive fish can biosynthesize the vitamin C de novo employing the enzyme called "L-gulonolactone oxidase" either from glucose or galactose (Dabrowski, 1994;Eo and Lee, 2008). However, most of the cultivable fish lack the enzyme "Lgulonolactone oxidase" to biosynthesize vitamin C in tissues; therefore, they need dietary vitamin C inclusion (Fracalossi et al., 2001;