Guruge, W.A.H.P, Amarasinghe N.J.De. S

Tab 4: Diet overlaps (s) among twelve co-occurring fish species in Tissawewa. n= number of fish species dissected forgut content analysis. For species abbreviation see table 4.4 in chapter 4. High overlap values (³ 0.67) are boldand underlined, and low overlap values (£0.33) are in italics and bold.N Fish species AM BC BD BS CS GG HG MYS OM ON RD TR2294 AM - 0.48 0.34 0.35 0.17 0.38 0.39 0.41 0.83 0.80 0.41 0.493005 BC - 0.79 0.61 0.40 0.65 0.61 0.72 0.57 0.57 0.70 0.502395 BD - 0.69 0.47 0.61 0.53 0.64 0.41 0.41 0.60 0.391251 BS - 0.40 0.57 0.54 0.57 0.45 0.48 0.56 0.4927 CS - 0.71 0.32 0.58 0.21 0.23 0.38 0.281120 GG - 0.55 0.82 0.44 0.45 0.62 0.521197 HG - 0.71 0.62 0.67 0.92 0.541712 MYS - 0.48 0.48 0.78 0.512557 OM - 0.92 0.50 0.58410 ON - 0.50 0.662531 RD - 0.4695 TR -Dietary overlaps in eleven co occurring fishspecies pairs during the pre drought period (= period 1)and the post drought period (= period 2) in theTissawewa are shown in Figure 3. For the most speciespairs dietary overlap values in the post drought periodwere higher than during the pre drought period. Of the10 possible species pairs in combination with AM inboth periods 1 and 2, two pairs recorded high overlaps,while in period 1, two pairs recorded low overlaps andin period 2, this dropped to one pair. In BC, out of 11possible species pairs, during period 1 one pair of eachshowedhigh and low overlaps, whereas in period 2, highoverlaps increased to 5 species pairs and no lowoverlaps were recorded (Figure 3). Of the 11 possiblespecies combination with BD, in period 1, one speciespair recorded high dietary overlap and in period 2, fourpairs recorded high overlaps and no species pairrecorded low overlaps. A similar trend was observedfor BS too. Of the 11 possible species pairs of BS, inperiod 1, none of species combination recorded highoverlaps, but in period 2, four pairs (57 %) indicatedhigh overlaps.Tab 5: Diet overlaps (s) among eleven co-occurring fish species in Tissawewa in two periods, the pre drought period(white dotted column) and the post drought period (dark column) species are compared pair wise, comparison iswith the species in the right hand corner of each figure with the species listed on the y-axis. Small overlaps are< 0.33, large overlaps are > 0.67. For number of observations per fish species see table 7.1. For speciesabbreviations see Figure 3.. Numbers next to the species legend indicates two periods, 1: pre-drought and 2:post-drought period.pre (1) and postfish species(2) drought period AM BC BD BS CS GG HG MYS OM ON RDAM1 0.51 0.31 0.31 0.01 0.37 0.42 0.38 0.85 0.84 0.39AM2 0.41 0.35 0.40 0.27 0.35 0.33 0.49 0.69 0.69 0.48BC1 0.75 0.50 0.19 0.59 0.58 0.62 0.59 0.55 0.64BC2 0.88 0.80 0.48 0.72 0.65 0.82 0.55 0.55 0.77BD1 0.63 0.30 0.52 0.45 0.53 0.38 0.33 0.54BD2 0.81 0.48 0.71 0.60 0.80 0.49 0.50 0.72BS1 0.16 0.47 0.39 0.47 0.41 0.41 0.43BS2 0.49 0.70 0.67 0.78 0.60 0.60 0.79CS1 0.55 0.08 0.41 0.03 0.03 0.17CS2 0.68 0.43 0.51 0.39 0.41 0.49GG1 0.51 0.85 0.44 0.41 0.59GG2 0.56 0.75 0.48 0.49 0.70HG1 0.66 0.49 0.45 0.91HG2 0.67 0.50 0.52 0.74MYS1 0.45 0.41 0.74MYS2 0.61 0.61 0.83OM1 0.91 0.45OM2 0.98 0.65ON1 0.41ON2 0.65