Habitat, Associations and Competition of Eight Barbus (= Puntius) Species (Pisces, Cyrinidae) Indigenous To Sri Lanka

Food and micro-habitat partitioning among cyprinids in Sri Lankan hill-stream pools

“…RD and DM were eating predominantly from the surface; but RD was also feeding in the water column and from rocky substrates. The vertical position of the fish species while feeding agrees well with most other authors who investigated niche segregation in hill streams of south-western Sri Lanka (Moyle and Senanayake 1984;Schut et al 1984;Wikramanayake and Moyle 1989). However, the diet results differed.…”

“…Also other studies of tropical river fish assemblages suggest that they are often predominantly structured by biological interactions (e.g. Moyle and Senanayake 1984;Schut et al 1984;Lowe-McConnell 1987;Arunachalam 2000).…”

“…Earlier studies focused on food, feeding habits, morphological features and reproduction Kortmulder et al 1978;, 1980, 1985. Later studies focused on niche segregation and the possible effect of competition as steering factor (Moyle and Senanayake 1984;Schut et al 1984;Wikramanayake and Moyle 1989;Wikramanayake 1990;Shirantha et al 2005). In none of these studies the availability of prey organisms in the environment were taken into account.…”

“…To study feeding behavior and micro-habitat occupation we analyzed fish gut contents and carried out direct underwater observations, furthermore, the environment was sampled to quantify the availability of potential food items of the fish. In this study we focus on microhabitat occupation, because the macro-habitats of the fishes belonging to this fish assemblage were earlier described in detail by Moyle and Senanayake (1984) and Schut et al (1984).…”

Effects of natural and anthropogenic environmental changes on riverine fish assemblages: a framework for ecological assessment of rivers

“…The knowledge about it remains somewhat superficial even if some authors have suggested that these interactions may be strong enough to have pervasive effects (Werner, 1984, Jackson et al, 2001. However, there is little evidence that either predation or interspecific competition strongly affects local fish assemblages in rivers with the exception of few studies (Zaret and Rand, 1971;Schut et al, 1984;Wikramanayake and Moyle, 1989;Taylor, 1996;Resetarits, 1997, Jackson et al 2001). If we first consider interspecific competition, we can hypothesize that if this is really an important process, then it should set an upper limit to the number of species in an assemblage (another species could only be accommodated by the loss of a species).…”