Browsing by Author "Villanueva, M.C."

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Diel feeding pattern and food consumption of selected fish populations in Asian reservoirs, Journal Aquatic Ecosystem and Development: Comparative Asian Perspectives
    (Backhuys Publishers, 2008) Amarasinghe, U.S.; Weliange, W.S.; Kakkaeo, M.; Villanueva, M.C.; Moreau, J.
  • No Thumbnail Available
    Item
    Diel feeding periodicity, daily ration and relative food consumption in some fish populations in three reservoirs of Sri Lanka
    (Aquatic Living Resources, 2006) Weliange, W.S.; Amarasinghe, U.S.; Moreau, J.; Villanueva, M.C.
    Twelve diel surveys were carried out in three reservoirs of Sri Lanka viz. Minneriya, Udawalawe and Victoria, to investigate diel feeding patterns, daily ration and relative food consumption in fish populations. Stomach content weights of different size classes of various fish species in the three reservoirs in 12 diel surveys were analysed using an iterative method, MAXIMS. Predominantly herbivorous or detritivorous fish species such as Amblypharyngodon melettinus and Oreochromis niloticus exhibited one peak in the diel feeding pattern. Two peak feeding periods were evident in predominantly insectivores and/or zooplanktivores (e.g., Puntius chola and Rasbora daniconius) and interestingly in macrophyte feeders (i.e., Etroplus suratensis, Puntius filamentosus and Tilapia rendalli). It might be possible that all species with two feeding peaks in diel feeding patterns rely on vision for feeding. Food consumption per biomass (Q/B ratio) defined as amount of food consumed per unit weight of an age-structured population of fish was estimated on the basis of the average quantities of food consumed over a long period of time by various size classes in order to minimize the bias of estimates.
  • No Thumbnail Available
    Item
    Trophic relationships and possible evolution of the production under various fisheries management strategies in a Sri Lankan reservoir
    (Reservoir and Culture-based Fisheries: Biology and Management, 2001) Moreau, J.; Villanueva, M.C.; Amarasinghe, U.S.; Schiemer, F.
    The ECOPATH trophic model has been used to describe an extensive study of the trophic relationships of Parakrama Samudra reservoir, Sri Lanka, during the 1970s. It has supported preliminary assessments made regarding the importance of unexploited fish stocks and can possibly provide the link to understanding the further evolution of the lake under various fisheries management schemes.