Fish Assemblages In Kerian River Tributaries, Kedah – Perak Border
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Date
2012-02
Authors
Zakeyuddin, Mohd. Shafiq
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Influence of habitat characteristics on fish distribution in selected Kerian
River tributaries was investigated from May 2008 to June 2009 by measuring several
physico-chemical parameters; DO, pH, temperature, salinity, conductivity, TDS,
velocity, river depth and width. Mean DO content in the water, ion conductivity,
water temperature, TDS content, water velocity, river width and depth were
significantly different among rivers (Kruskal-Wallis Test, P < 0.05). Forty eight fish
species from 20 families were collected using a cast net, an electrofishing and an
insect net. Cyprinidae had the highest abundance with 645 individuals or 73.3%
from all the catch. Bogak River had the most diverse fish community (H’=2.353)
while Kangar River was the least diverse (H’=1.344). The CCA ordination explained
significant relationship (Monte Carlo permutation tests, p < 0.05) between fish
species and environmental variables. The length-weight relationship was analyzed
for six most abundant fish species by substituting respective fish length and weight
values into W=aLb. The fish growth (b) showed that four species, D. regina
(b=3.256), P. binotatus (b=3.911), R. sumatrana (b=3.642) and C. apogon (b=3.623)
had positive allometric growth, while two species, Labiobarbus sp. (b=2.898) and A.
choironrhycos (b=2.427) had negative allometric growth. All species had fast growth
rates as indicated by a growth constant (K) of the estimated growth parameters,
ranging from 1.03 year-1 to 1.60 year-1. Fishing mortality (F) that varied from 0.33
year-1 to 0.76 year-1, were lower than calculated natural mortality (M) of 1.92 year-1
to 2.40 year-1. Exploitation rates for all selected species (0.26 year-1 - 0.13 year-1) fell
below the optimal stock exploitation rate. The analysis of stomach content indicated
Devario regina was an active feeder when 121 of 126 individuals had full stomachs.
Formicidae was the most frequently eaten (based on IRI) in high abundance hence
was its main diet while other terrestrial and aquatic insects and plant materials were
taken in lesser amount. The dominance of Formicidae in the stomach of D. regina
indicated the importance of riparian vegetations as shelters for its food sources.
Description
Keywords
Fish distribution in selected Kerian River tributaries , measuring several physico-chemical parameters