Population Parameters, Feeding And Reproductive Biology Of Beardless Barb, Cyclocheilichthys Apogon (Valenciennes, 1842) From Selected Tributaries Of Muda Reservoir, Kedah, Malaysia
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Date
2018-08
Authors
Rosli, Nor Aziella Mohd
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Abstract
Scanty information is known about the biological aspects of Cyclocheilichthys
apogon and as such, a study on the biology this species was conducted in five
tributaries of Muda Reservoir for 18 months from March 2014 untill August 2015.
Monthly sampling was conducted to collect the water samples and fish specimens.
This study includes the determination of the physico-chemical water quality
parameters, length-weight relationships and relative condition factor of C. apogon,
population parameters, feeding and reproductive biology of C. apogon. No significant
differences (p > 0.05) were observed among sampling stations in pH, nitrite, nitrate
and ammonia concentration and no significant differences (p > 0.05) were observed
in water temperature, conductivity, water depth, dissolved oxygen, total dissolved
solid, current flow, nitrate and phosphate concentration among sampling months. All
the values of the physico-chemical water quality analysis in tributaries of Muda
Reservoir were in safe level in Class I and IIA. C. apogon was found to grow in
isometric growth pattern using the length-weight relationships. The values of relative
condition factor of C. apogon was higher than one shows the better condition of C.
apogon in this tributaries. From the population parameters study, C. apogon was
estimated to reach length infinity (L∞) at 21.5 cm, with moderate growth rate (K) of
0.42 year-1. The length at first capture (Lc) of C. apogon was estimated at 8.67 cm.
The total mortality (Z) of C. apogon was higher (3.17 year-1) with the fishing mortality (F) of 1.95 year-1 was higher than the natural mortality (M) of 1.22 year-1.
The exploitation rate (E) of 0.62 year¯¹ of C. apogon was slightly exploited than the
optimum exploitation level (E0.1) of 0.61 year¯¹. The exploitation of this species
should be managed properly in sustainable way for fish resources continuity before it
reaches the estimated maximum allowable limit of exploitation (Emax) of 0.76 year¯¹.
C. apogon recruit in two recruitment pattern per year in April and September. From
the feeding biology study, C. apogon in tributaries of Muda Reservoir was
euryphagous-omnivores by consuming mixed diet of animal and plant-based food
with the preferences to the animal-based food. The main food contents were
Bacillariophyta, Crustacea, Insecta and worms (Nematoda & Annelida). Other food
materials such as Chlorophyta, Cyanophyta, unidentified macrophyte particles,
unidentified weeds, fish scales and eggs were less encountered indicating their low
importance to fishes or mistakenly consumed. The variations in the type of diet
consumed by C. apogon were observed between immature and mature fish, dry and
wet months, length size classes and sampling stations. A diet shift from plant
materials to animal materials was observed from immature fish to mature fish. The
same diet shift from plant materials to animal materials was observed from smaller
size fish to bigger size fish. C. apogon consumed more on animal materials in Stations
1, 2 and 3 compared to plant materials and consumed more on plant materials in
Stations 4 and 5 compared to animal materials. From the reproductive biology study,
the sex ratio of male and female C. apogon was 1.08: 1.00 (male: female). The
maturity stages of male and female C. apogon were classified into six maturity stages.
C. apogon was a ‘group synchronous spawner’ according to histological analysis and
oocyte size frequency distribution. Female C. apogon reach sexual maturity at smaller
size (10.0 cm) than the male C. apogon (11.3 cm). The major spawning season of C.apogon was tightly related to the rainy or wet month in September. Fecundity of C.
apogon ranged from 135 to 2260 eggs per gonad and it is more related to gonad
weight rather than body weight and total length. Informations obtained from this
study would be useful to fill in the gap of knowledge on the population parameters,
feeding and reproductive biology of C. apogon in tributaries of Muda Reservoir as
well as for future comparisons regarding this species.
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Keywords
Natural history