In this study, we document an increasing trend of catches of alien fish species from the Ganga River system. The changing fishery during 1980 to 2011 and the fish yield rate (kg km −1 ) are positively correlated with an invasion coefficient index (I xi ) of alien species within the river. The reproductive propagule pressure (PPP) of alien fishes (Cyprinus carpio, Oreochromis niloticus, Aristichthys nobilis, Ctenopharyngodon idella, Hypophthalmichthys molitrix and Clarias gariepinus) was determined and found to be 19.45×10 6 for C. carpio, 0.33×10 6 for O. niloticus and 0.82×10 6 for A. nobilis at confluences suggesting that these alien species may be migrating into new habitats. Further, these invaded species exhibited all reproductive stages, indicating their likely establishment within the river. The trophic spectrum of alien fishes spanned all levels and the gut repetitive index (GRI) indicated that that food items in most of the fishes were similar showing early trends of food-web alteration and biotic homogenization. The results of this study suggested a continuous decline in the catch of local fishes by wet weight, particularly Indian major carps (IMC) from 128.91 kg km −1 to 38.58 kg km −1 owing to increased catches of alien species from nil to 384.27 kg km −1 . Invasion of alien species in the Ganga River represented one of many possible causes of the decline in river health and overall loss of native aquatic communities.

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Laying hens continue to improve in egg production (EP) and feed efficiency (FE), and therefore, it is relevant to re-examine their digestible balanced protein (BP) requirements. From 27 to 66 wk of age, hens (Lohmann-LSL Lite) were fed diets designed to provide 550, 625, 700, 775, or 850 mg hen −1 d −1 of amino acid balanced digestible lysine (Dlys). Response criteria included EP, egg weight (EW), feed intake (FI), mortality, egg mass (EM), egg size classifications, FE (kg feed kg −1 EM), and lysine efficiency (LE; mg Dlys g −1 EM). The experiment was a completely randomized design, and data were analyzed using regression analysis. Differences were considered significant if P ≤ 0.05. Hen-day (HD) EP, EW, EM, FI, and LE increased and FE and mortality decreased in a quadratic fashion with increasing Dlys intake, while the proportion of cracked eggs increased linearly. Egg size classifications increased linearly (jumbo, extra-large) and quadratically (large) or decreased in a quadratic manner (medium, small) with increasing Dlys intake. Maximum HDEP, EW, and EM, and minimum FE were achieved at 769, 903, 836, and 839 mg hen −1 d −1 intake of Dlys, respectively. In conclusion, the digestible BP requirement of laying hens varies with response criteria.

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